| 1. |
Mufflers for aeronautic engines
( 1917) by Diederichs, H Upton, G B [11 pages; 0.4
MB] |
|
Abstract: Report presents the design, development
and experimental results of muffling devices used to reduce noise
generated by the airplane power plant. |
| 2. |
Thermodynamic efficiency of
present types of internal combustion engines for aircraft (
1917) by Lucke, Charles E [115 pages; 6.4 MB] |
|
Abstract: Report presents requirements of
internal combustion engines suitable for aircraft. Topics include: (1)
service requirements for aeronautic engines - power versus weight,
reliability, and adaptability factors, (2) general characteristics of
present aero engines, (3) aero engine processes and functions of parts
versus power-weight ratio, reliability, and adaptability factors, and
(4) general arrangement, form, proportions, and materials of aero parts
- power-weight ratio, reliability, and adaptability. |
| 3. |
The steadiness factor in engine
sets ( Jan 1920) by W. Margoulis [13 pages; 0.5 MB] |
|
Abstract: A discussion on the Steadiness Factor
in Engine Sets was prepared by the Paris Office of the National
Advisory Committee for Aeronautics. |
| 4. |
Airplane performance as
influenced by the use of a supercharged engine ( May 1920)
by George De Bothezat [9 pages; 0.2 MB] |
|
Abstract: The question of the influence of a
supercharged engine on airplane performance is treated here in a first
approximation, but one that gives an exact idea of the advantage of
supercharging. Considered here is an airplane that climbs first with an
ordinary engine, not supercharged, and afterwards climbs with a
supercharged engine. The aim is to find the difference of the ceilings
reached in the two cases. In the case of our figure, the ceiling from
25,000 feet is increased to 37,000 feet, the supercharging maintaining
the power only up to 20,000 feet. This makes, in comparison with an
engine without supercharging, an increase of about 50 percent. |
| 5. |
Instrument for measuring engine
clearance volumes ( Dec 1920) by S. W. Sparrow [13
pages; 0.7 MB] |
|
Abstract: With the advent of the V type engine, a
new method to measure the clearance volume in cylinders was needed. It
was suggested that this measurement could be made by a process which
consisted essentially of simultaneously changing both a known and
unknown volume of gas by a known amount and then calculating the
magnitude of the unknown from the resulting difference in pressure
between the two. An instrument based on this design is described. |
| 6. |
Notes on the design of
supercharged and overdimensioned aircraft engines ( Jul 1920)
by Schwager [8 pages; 0.2 MB] |
|
Abstract: The purely supercharged motor must be
considered as overloaded, because the increase of power with altitude
reached by supercharging is limited. |
| 7. |
Experience with geared
propeller drives for aviation engines ( Sep 1920) by K.
Kutzbach [24 pages; 1.4 MB] |
|
Abstract: I. The development of the gear wheels:
(a) bending stresses; (b) compressive stresses; (c) heating; (d)
precision of manufacture. II. General arrangement of the gearing. III.
Vibration in the shaft transmission. An overview is given of experience
with geared propeller drives for aviation engines. The development of
gear wheels is discussed with emphasis upon bending stresses,
compressive stresses, heating, and precision in manufacturing. With
respect to the general arrangement of gear drives for airplanes, some
principal rules of mechanical engineering that apply with special force
are noted. The primary vibrations in the shaft transmission are
discussed. With respect to vibration, various methods for computing
vibration frequency and the influence of elastic couplings are
discussed. |
| 8. |
Recent efforts and experiments
in the construction of aviation engines ( Sept 1920) by
Schwager [18 pages; 1.2 MB] |
|
Abstract: It became evident during World War I
that ever-increasing demands were being placed on the mean power of
aircraft engines as a result of the increased on board equipment and
the demands of aerial combat. The need was for increased climbing
efficiency and climbing speed. The response to these demands has been
in terms of lightweight construction and the adaptation of the aircraft
engine to the requirements of its use. Discussed here are specific
efforts to increase flying efficiency, such as reduction of the number
of revolutions of the propeller from 1400 to about 900 r.p.m. through
the use of a reduction gear, increasing piston velocity, locating two
crankshafts in one gear box, and using the two-cycle stroke. Also
discussed are improvements in the transformation of fuel energy into
engine power, the raising of compression ratios, the use of
super-compression with carburetors constructed for high altitudes, the
use of turbo-compressors, rotary engines, and the use of variable pitch
propellers. |
| 9. |
Increase in maximum pressures
produced by preignition in internal combustion engines ( Aug
1920) by S. W. Sparrow [7 pages; 0.1 MB] |
|
Abstract: With the high compression ratio of the
aviation engine, preignition is of frequent occurrence. That extremely
high temperatures are a result, is fairly well recognized, but little
attention seems to have been given to the pressures that prevail in the
cylinder under these conditions. |
| 10. |
Tests of the Daimler D-IVa
engine at a high altitude test bench ( Oct 1920) by W.
G. Noack [21 pages; 1.1 MB] |
|
Abstract: Reports of tests of a Daimler IVa
engine at the test-bench at Friedrichshafen, show that the decrease of
power of that engine, at high altitudes, was established, and that the
manner of its working when air is supplied at a certain pressure was
explained. These tests were preparatory to the installation of
compressors in giant aircraft for the purpose of maintaining constant
power at high altitudes. |
| 11. |
A new process for the
production of aircraft-engine fuels ( 1920) by Paris,
Auguste Jean, Jr Paris, W Francelyn [4 pages; 0.1 MB] |
|
Abstract: Report describes experiments conducted
on a new method of producing high-grade aviation gasoline at a test
laboratory established at Charleston, W. Va. For the National Advisory
Committee for Aeronautics. |
| 12. |
The altitude laboratory for the
test of aircraft engines ( 1920) by Dickinson, H C
Boutell, H G [19 pages; 1.2 MB] |
|
Abstract: Report presents descriptions,
schematics, and photographs of the altitude laboratory for the testing
of aircraft engines constructed at the Bureau of Standards for the
National Advisory Committee for Aeronautics. |
| 13. |
A study of airplane engine
tests ( 1920) by Gage, Victor R [35 pages; 2.1 MB] |
|
Abstract: This report is a study of the results
obtained from a large number of test of an Hispano-Suiza airplane
engine in the altitude laboratory of the Bureau of Standards. It was
originally undertaken to determine the heat distribution in such an
engine, but many other factors are also considered as bearing on this
matter. |
| 14. |
Power characteristics of fuels
for aircraft engines ( 1920) by Dickinson, W S James, W
S Roberts, E W Gage, V R Harper, D R Iii [30 pages; 1.7 MB] |
|
Abstract: Report presents the summation of
results obtained in the testing of fuels of various compositions and
characteristics in the altitude laboratory. The data upon which this
report is based has had an important influence upon the writing of
specifications for the various grades of aviation fuels. |
| 15. |
Carbureting conditions
characteristics of aircraft engines ( 1920) by Tice,
Percival S [6 pages; 0.3 MB] |
|
Abstract: Tests were conducted at the altitude
laboratory erected at the Bureau of Standards for the National Advisory
Committee for Aeronautics to determine the changes in engine
performance with changes in atmospheric temperature and pressure at
various levels above the earth's surface, with special reference to (a)
the variables affecting the functioning of the carburetor and (b) the
changes in performance resulting from variables in the carburetor
itself. This report constitutes a concise statement of the difficulties
to be encountered in this branch of carburetion. |
| 16. |
Results of tests on radiators
for aircraft engines ( 1920) by Dickinson, H C James, W
S Kleinschmidt, R V [39 pages; 2.1 MB] |
|
Abstract: Part 1 is to present the results of
tests on 56 types of core in a form convenient for use in the study of
the performance of and possible improvements in existing designs.
Working rules are given by which the data contained in the report may
be used, and the most obvious conclusions as to the behavior of cores
are summarized. Part 2 presents the results of tests made to determine
the pressure necessary to produce water flows up to 50 gallons per
minute through an 8-inch square section of radiator core. These data
are of special value in evaluating the hydraulic head against which the
circulating pump is required to operate. |
| 17. |
Investigation of the muffling
problem for airplane engines ( 1920) by Upton, G. B.,
Gage, V. R. [41 pages; 3.4 MB] |
|
Abstract: The experimentation presented in this
report falls in two divisions: first, the determination of the relation
between back pressure in the exhaust line and consequent power loss,
for various combinations of speed and throttle positions of the engine;
second, the construction and trial of muffler designs covering both
type and size. Report deals with experiments in the development of a
muffler designed on the principle which will give the maximum muffling
effect with a minimum loss of power. The main body of the work has been
done on a Curtiss OX eight-cylinder airplane engine, 4 by 5 inches,
rated 70 horsepower at 1,200 revolutions per minute. For estimation of
the muffling ability and suppression of "bark" of individual exhausts,
the "Ingeco" stationary, single cylinder, 5 1/2 by 10 inch, throttling
governed gasoline engine, and occasionally other engines were used. |
| 18. |
The 300 H.P. Benz aircraft
engine ( Jan 1921) by A. Heller [18 pages; 1.1 MB] |
|
Abstract: A description is given of the Benz
12-cylinder aircraft engine. The 300 H.P. engine, with the cylinders
placed at an angle of 60 degrees not only realizes a long-cherished
conception, but has received refinement in detail. It may be described
as a perfect example of modern German aircraft engine construction.
Here, a detailed description is given of the construction of this
engine. Emphasis is placed on the design and construction of the
cylinders, pistons, and connecting rods. Also discussed are engine
fitting, lubrication, oil pumps, bearings, the oil tank, fuel pump,
carburetors, and cooling system. |
| 19. |
Airplane crashes: engine
troubles : a possible explanation ( Mar 1921) by
Stanwood W. sparrow [7 pages; 0.2 MB] |
|
Abstract: The aim was to bring attention to what
might be the cause of some aircraft accidents for which there was no
satisfactory explanation. The author notes that in testing aircraft
accidents at the Bureau of Standards, it happened frequently that the
engine performance became erratic when the temperature of the air
entering the carburetor was between 0 C and 20 C. Investigation
revealed the trouble to have been caused by the formation and
collection of snow somewhere between the entrance to the carburetor and
the manifold, probably at the throttle. Proof scarcely less convincing
was obtained during engine tests. The results of such engine tests are
described. Granting that the loss of power and the sudden increases in
power were caused by the condensation of moisture from the air and the
subsequent formation of snow, two solutions proved effective. The
removal of the moisture or an increase in temperature cured the
problem. |
| 20. |
The dynamometer hub for the
testing propellers and engines during flight ( Jul 1921)
by O. Enoch [26 pages; 1.3 MB] |
|
Abstract: The need for a device to measure flight
resistance, engine and propeller power, and efficiency during flight
grew in proportion to the demand for increased flying capacity in
military types of aircraft. Here, a dynamometer hub was inserted
between the engine and the propeller. Taken as a whole, the tests that
were conducted show that though the dynamometer is a sensitive
instrument liable to numerous derangements, it is undeniably useful
even in its present form, when handled with care and skill.
Facilitating, as it does, the possibility of maintaining the fixed
position of the engine, the blocking out of the weight effect when the
plane is in the sloping position, and the possibility of taking direct
measurements of force at the point of transmission, the dynamometer
appears to be by far the best solution of the problem of a flying test
bench, utilized as a hydraulic balance with the smallest possible
measuring stroke and the least tendency to oscillation. |
| 21. |
The problem of fuel for
aviation engines ( Jul 1921) by W. S. James [24 pages;
0.9 MB] |
|
Abstract: This paper addresses the physical
properties which may be demanded of fuels for aviation use and the
means that may be adopted by the engine manufactures to properly meet
the demands necessitated by the use of such fuel. In the choice of a
fuel the following factors must be considered: (1) its composition; (2)
the quantity available; (3) the price per heat unit; and (4) the
possibility of keeping stocks in aerial ports both at home and abroad.
It is also important to know if the change from one fuel to another
will necessitate any serious modification of the engine. |
| 22. |
The calculated performance of
airplanes equipped with supercharging engines ( 1921) by
Kemble, E C [54 pages; 2.8 MB] |
|
Abstract: In part one of this report are
presented the theoretical performance curves of an airplane engine
equipped with a supercharging compressor. In predicting the gross power
of a supercharging engine, the writer uses temperature and pressure
correction factors based on experiments made at the Bureau of Standards
(NACA report nos. 45 and 46). Means for estimating the temperature rise
in the compressor are outlined. Part two of this report presents an
estimation of the performance curves of an airplane fitted with a
supercharging engine. A supercharging installation suitable for
commercial use is described, and it is shown that with the use of the
compressor a great saving in fuel and a considerable increase in
carrying capacity can be effected simultaneously. In an appendix the
writer derives a theoretical formula for the correction of the thrust
coefficient of an airscrew to offset the added resistance of the
airplane due to the slip-stream effect. |
| 23. |
Performance of a Liberty 12
airplane engine ( 1921) by Sparrow, S W White, H S [20
pages; 1 MB] |
|
Abstract: In cooperation with the Engineering
Division of the Air Service of the United States Army, a Liberty-12
engine has been tested at the Bureau of Standards. The program of tests
was planned to yield that information considered most important in
determining the value of the engine for aviation. Full power runs were
made at the ground, at 25,000 feet, and at several intermediate
altitudes. To determine the mechanical efficiency of the engine,
friction horsepower was measured at the ground and at 15,000 feet. As a
basis for predicting engine performance with a propeller, a series of
tests was made in which the dynamometer load and engine throttle were
adjusted at each speed to simulate the engine load which would be
imposed at that speed by a propeller operating under normal full load
at 1,700 r.p.m. Among the quantities calculated from the test
measurements are: brake horsepower; break mean effective pressure; fuel
consumption; mixture ratio; mechanical, thermal, and volumetric
efficiency; and the percentage of the heat in the fuel appearing in the
jacket water and in the exhaust. Jacket water temperature, oil
temperature, manifold pressure, etc., are recorded to show the
conditions under which the test was made. |
| 24. |
Performance of a 300-horsepower
Hispano-Suiza airplane engine ( 1921) by Sparrow, S W
White, H S [22 pages; 0.9 MB] |
|
Abstract: The National Bureau of Standards tested
a 300-horsepower Hispano-Suiza engine to determine the characteristic
performance of the engine at various altitudes. The engine was operated
at the ground, at 25,000 feet, and at intermediate altitudes, both at
full loads similar to those that would be imposed upon the engine at
various speeds by a propeller whose normal full-load speed was 1,800
r.p.m. Friction horsepower also was determined in order that the
mechanical efficiency of the engine might be calculated. From the test
data there were computed the brake horsepower, brake mean effective
pressure, specific fuel consumption, mixture ratio, jacket loss,
exhaust loss, and thermal, mechanical, and volumetric efficiencies. A
record of jacket water temperatures, oil temperatures, manifold
pressures, etc., shows the conditions under which the test was made. |
| 25. |
Turbulence in the air tubes of
radiators for aircraft engines ( 1921) by Parsons, S R
[13 pages; 0.7 MB] |
|
Abstract: This report describes an investigation
of the characteristics of flow in the air passages of aircraft
radiators. The work was done by the National Bureau of Standards for
the National Advisory Committee for Aeronautics. |
| 26. |
A high-speed engine pressure
indicator of the balanced diaphragm type ( 1921) by
Dickinson, H C Newell, F B [15 pages; 0.9 MB] |
|
Abstract: This report describes a
pressure-measuring device especially adapted for use in mapping
indicator diagrams of high-speed internal combustion engines. The cards
are obtained by a point-to-point method giving the average of a large
number of engine cycles. The principle involved is the balancing of the
engine cylinder pressure against a measured pressure on the opposite
side of the metal a diaphragm of negligible stiffness. In its
application as an engine indicator the phase of the engine cycle to
which a pressure measurement corresponds is selected by a timing
device. The report discusses briefly the errors which must be avoided
in the development of an indicator for light high-speed engines, where
vibration is serious, and outlines the principles underlying the design
of this instrument in order to be free of such errors. A detailed
description of the instrument and accessories follows together with
operating directions. |
| 27. |
Factors of airplane engine
performance ( 1921) by Gage, Victor R [29 pages; 1.9 MB]
|
|
Abstract: This report is based upon an analysis
of a large number of airplane-engine tests. It contains the results of
a search for fundamental relations between many variables of engine
operation. The data used came from over 100 groups of tests made upon
several engines, primarily for military information. The types of
engines were the Liberty 12 and three models of the Hispano-Suiza. The
tests were made in the altitude chamber, where conditions simulated
altitudes up to about 30,000 feet, with engine speeds ranging from
1,200 to 2,200 r.p.m. The compression ratios of the different engines
ranged from under 5 to over 8 to 1. The data taken on the tests were
exceptionally complete, including variations of pressure and
temperature, besides the brake and friction torques, rates of fuel and
air consumption, the jacket and exhaust heat losses. |
| 28. |
The Goebel rotary engine
( March 1921) by (Author(s) Not Available) [3 pages; 0 MB] |
|
Abstract: This report presents a table of
specifications of the rotary engine and a very brief description of
some of the notable features such as the exhaust valves controlled by
means of a fixed cam gear. |
| 29. |
Abacus giving the variation of
the mean pressure of an aviation engine as a function of its speed of
rotation ( March 1921) by Margoulis, W [13 pages; 0.6
MB] |
|
Abstract: Comparing the results of the
calculations for computing the mean pressure of an aviation engine for
any number of revolutions, with those of experiment, the writer, by
numerous examples, shows the perfect agreement between them. This
report will show that, by means of a special abacus, an engineer can
instantly plot the characteristics of an engine. |
| 30. |
The coupling of engines
( April 1921) by Boccaccio, Paul [8 pages; 0.3 MB] |
|
Abstract: This report examines the idea of
coupling numerous engines together to turn a single propeller, which
the author feels would free aircraft design from the problems of
multi-engine and propeller design. |
| 31. |
The dynamometer hub and the
flywheel of the engine ( June 1921) by Everling, E
(German Aeronautical Laboratory) [9 pages; 0.2 MB] |
|
Abstract: No Abstract Available |
| 32. |
Preliminary calculation of
cylinder dimensions for aircraft engines ( September 1921)
by Schwager, Otto [9 pages; 0.2 MB] |
|
Abstract: It is extremely important in building
aircraft engines to determine the requisite cylinder dimensions as
accurately as possible, in order that the weight required for a given
power shall not be excessive. This report presents a calculation method
that depends on the air requirement of the fuel. |
| 33. |
The small diesel engine as an
automotive engine ( September 1921) by Frey, Ernst [18
pages; 0.6 MB] |
|
Abstract: Essential principles for building small
diesel engines and also structural details so far as feasibility are
presented. |
| 34. |
Development of aeronautical
engines by the Army and Navy ( March 03, 1921) by
(Author(s) Not Available) [5 pages; 0.2 MB] |
|
Abstract: Different aircraft engines are
categorized as being of interest to only the Army or Navy or to both
armed services. A listing of the different engines is presented along
with some statistics, namely, horsepower. |
| 35. |
Comparing maximum pressures in
internal combustion engines ( June, 1922) by Stanwood W.
Sparrow, Stephen M. Lee [5 pages; 0.1 MB] |
|
Abstract: Thin metal diaphragms form a
satisfactory means for comparing maximum pressures in internal
combustion engines. The diaphragm is clamped between two metal washers
in a spark plug shell and its thickness is chosen such that, when
subjected to explosion pressure, the exposed portion will be sheared
from the rim in a short time. |
| 36. |
Comparative performance with
direct and geared engines ( October, 1922) by W. S.
Diehl [13 pages; 0.4 MB] |
|
Abstract: Comprehensive tests were made to
compare the performance of the F-5-L Boat Seaplane fitted with direct
drive and Liberty engines. Details are given on the test conditions.
The conclusions of the comparison tests follow. 1) An F-5-L with geared
engines takes off in approximately 90 percent of the time required for
the same airplane with standard direct drive engines. An F-5-L with
geared engines climbs in 20 minutes to an altitude approximately 20
percent greater than that obtained with the standard direct drive on
the same airplane. 3) There is a large difference between the climbs of
the two airplanes of the same type. This difference will always be more
pronounced when the climb is normally slow. In the case of the F-5-L
airplanes under construction, it is of the order of a 10 percent
difference in altitude on a 20 minute climb. 4) The maximum speed of an
F-5-L with geared engines is about 3.5 percent greater than the maximum
speed of the same airplane with standard direct drive engines (at the
same engine r.p.m.). 5) The fuel consumption is probably less effected
by the type of drive than by inherent differences in the performance of
different airplanes. |
| 37. |
Engine pistons of light metal
( June 1922) by Becker, G [8 pages; 0.2 MB] |
|
Abstract: This report presents the results of
testing 32 sets of light metal pistons from 16 different aluminum and
magnesium alloys, 2 sets of cast iron pistons, and one piston of pure
electrolytic copper. The many-fold mutual relations between material
properties, shape, thermic and dynamic processes in the engine were
clarified by comprehensive technical, thermic, chemical, physical and
metallographic investigations of pistons and piston materials. |
| 38. |
Training of aeronautical
engineers ( October 1922) by Warner, Edward P
(Massachusetts Inst. of Tech) [4 pages; 0.1 MB] |
|
Abstract: The requirements and preliminary
coursework for aeronautical engineering are discussed. |
| 39. |
The "Universal" adjustable and
reversible propeller built by Paragon Engineers, Inc., Baltimore, Md
( November 1922) by Bacon, David L [10 pages; 0.3 MB] |
|
Abstract: A device which does for the aircraft
what change speed gears do for the automobile is the invention of
Spencer Heath. It comprises a system of special blades and a mechanism
for varying the pitch of the blades from zero to 360 degrees, while in
flight or otherwise. |
| 40. |
Type of engine to employ
( November 1922) by Hamel, M [10 pages; 0.3 MB] |
|
Abstract: The engine of a commercial airplane
must, above all, be sure and durable. It seems therefore, that we must
use engines with vertical cylinders or in the V form with quite a small
angle. |
| 41. |
Definition of terms used in
connection with commercial aircraft engines ( November 1922)
by Martinot, Lagarde [5 pages; 0.1 MB] |
|
Abstract: To facilitate standardization of
certain terms and definitions relating to engines and airplanes a list
of definitions is provided. |
| 42. |
Influence of design on cost of
operating airplanes ( December 1922) by Black, Archibald
(American Society of Mechanical Engineers) [27 pages; 0.9 MB] |
|
Abstract: The author discusses cost of operating
commercial airplanes and endeavors to clear up prevalent
misunderstandings. Curves of operating cost for varying duration,
speed, reserve horsepower, etc. are developed. |
| 43. |
The problem of landing
( February 1922) by Pistolesi, E (War Department Air Services,
Engineering Division, McCook Field, Dayton, Ohio.) [16 pages; 0.5 MB] |
|
Abstract: The author discusses various aspects of
landing aircraft such as the actual process of touchdown and the
problems associated with the tail skid touching the ground before the
landing gear. |
| 44. |
Vibrations of aviation engines
( 1922) by Lagarde, Martinot C [19 pages; 0.6 MB] |
|
Abstract: Different causes of airplane engine
vibration are given as well as devices to measure vibration. |
| 45. |
The "Universal propeller":
built by Paragon Engineers, Inc., Baltimore, Md ( March 1922)
by Bacon, David L [9 pages; 0.3 MB] |
|
Abstract: At the request of the N.A.C.A. the
"Universal Propeller" was operated and explained by the inventor, Mr.
Spencer Heath, for the purpose of demonstrating the following features
of design: 1) Elimination of continuously running gears, collars or
bearings in the pitch control mechanism; 2) The use of engine power in
place of manual labor in changing blade angle; 3) The absence of any
structural limitation to the range of blade angles available and the
possibility of limiting the blade travel between any two predetermined
extreme positions; 4) Continuous indication on the instrument board of
the blade position; 5) Automatic throttling of the engine while the
propeller is passing through the position of neutral pitch. |
| 46. |
Bagnulo heavy fuel internal
combustion engine and its employment in aviation ( March 1922)
by Fiore, Amedeo [9 pages; 0.3 MB] |
|
Abstract: We see with great satisfaction that
Bagnulo's studies and experiments on his high-speed, heavy-fuel
engines, promise to solve not only the general problem of economical
power and hence of thermal efficiency, but also all other special
problems, of weight and space, and, what is still more important, range
of error. |
| 610. |
An analysis of
normal-acceleration and airspeed data from a four-engine type of
transport ( Aug 1953) by Thomas L. Coleman, Paul W. J.
Schumacher [28 pages; 0.8 MB] |
|
Abstract: airplane in commercial operation on an
eastern united states route from November 1947 to February 1950 An
analysis of 48,187 hours of normal-acceleration and airspeed data
obtained on a four-engine type of transport airplane in commercial
operation on an eastern United States route from November 1947 to
February 1950 has been made to determine the gusts and gust loads for
the operations. The results, covering operation to 20,000 feet,
indicate that the maximum gust velocity encountered in a given number
of flight miles was less than that for a low-altitude operation (below
10,000 feet) but the accelerations experienced were about as severe in
terms of percentage of limit load factor as for the operations below
10,000 feet. |
| 611. |
Effect of rotor- and
stator-blade modifications on surge performance of an 11-stage
axial-flow compressor II : redesigned compressor for XJ-40-WE-6 engine
( May 25, 1953) by Conrad, E William Essig, Robert H Finger,
Harold B [45 pages; 1.7 MB] |
|
Abstract: No Abstract Available |
| 612. |
Effects of fuel temperature and
fuel distribution on the combustion efficiency of a 16-inch ram-jet
engine at a simulated Mach number of 2.9 ( January 08, 1953)
by Dangle, E E Cervenka, A J Bahr, D W [28 pages; 1 MB] |
|
Abstract: No Abstract Available |
| 613. |
Free-flight performance of a
rocket-boosted, air-launched 16-inch-diameter ram-jet engine at Mach
numbers up to 2.20 ( February 03, 1953) by Disher, John
H Kohl, Robert C Jones, Merle L [36 pages; 1.2 MB] |
|
Abstract: The investigation of air-launched
ram-jet engines has been extended to include a study of models with a
nominal design free-stream Mach number of 2.40. These models require
auxiliary thrust in order to attain a flight speed at which the ram jet
becomes self-accelerating. A rocket-boosting technique for providing
this auxiliary thrust is described and time histories of two
rocket-boosted ram-jet flights are presented. In one flight, the model
attained a maximum Mach number of 2.20 before a fuel system failure
resulted in the destruction of the engine. Performance data for this
model are presented in terms of thrust and drag coefficients, diffuser
pressure recovery, mass-flow ratio, combustion efficiency, specific
fuel consumption, and over-all engine efficiency. |
| 614. |
Summary report on analytical
evaluation of air and fuel specific-impulse characteristics of several
nonhydrocarbon jet-engine fuels ( February 19, 1953) by
Breitwieser, Roland Gordon, Sanford Gammon, Benson [59 pages; 1.7 MB] |
|
Abstract: No Abstract Available |
| 615. |
Analytical comparison of
turbine-blade cooling systems designed for a turbojet engine operating
at supersonic speed and high altitude I : liquid-cooling systems
( February 20, 1953) by Schramm, Wilson B Nachtigall, Alfred J
Arne, Vernon L [54 pages; 2.2 MB] |
|
Abstract: No Abstract Available |
| 616. |
Analytical comparison of
turbine-blade cooling systems designed for a turbojet engine operating
at supersonic speed and high altitude II : air-cooling systems
( February 19, 1953) by Schramm, Wilson B Arne, Vernon L
Nachtigall, Alfred J [52 pages; 2.2 MB] |
|
Abstract: No Abstract Available |
| 617. |
Effect of uneven air-flow
distribution to the twin inlets of an axial-flow turbojet engine
( January 26, 1953) by Wallner, Lewis E Conrad, E William Prince,
William R [36 pages; 1.2 MB] |
|
Abstract: No Abstract Available |
| 618. |
Acceleration of
high-pressure-ratio single-spool turbojet engine as determined from
component performance characteristics I : effect of air bleed at
compressor outlet ( March 10, 1953) by Rebeske, John J ,
Jr Rohlik, Harold E [22 pages; 0.7 MB] |
|
Abstract: An analytical investigation was made to
determine from component performance characteristics the effect of air
bleed at the compressor outlet on the acceleration characteristics of a
typical high-pressure-ratio single-spool turbojet engine. Consideration
of several operating lines on the compressor performance map with two
turbine-inlet temperatures showed that for a minimum acceleration time
the turbine-inlet temperature should be the maximum allowable, and the
operating line on the compressor map should be as close to the surge
region as possible throughout the speed range. Operation along such a
line would require a continuously varying bleed area. A relatively
simple two-step area bleed gives only a small increase in acceleration
time over a corresponding variable-area bleed. For the modes of
operation considered, over 84 percent of the total acceleration time
was required to accelerate through the low-speed range ; therefore,
better low-speed compressor performance (higher pressure ratios and
efficiencies) would give a significant reduction in acceleration time. |
| 619. |
Comparison of theoretically and
experimentally determined effects of oxide coatings supplied by fuel
additives on uncooled turbine-blade temperature during transient
turbojet-engine operation ( March 30, 1953) by Schafer,
Louis J Stepka, Francis S Brown, W Byron [46 pages; 1.7 MB] |
|
Abstract: An analysis was made to permit the
calculation of the effectiveness of oxide coatings in retarding the
transient heat flow into turbine blades when the combustion gas
temperature of a turbojet engine is suddenly changed. The analysis is
checked with experimental data obtained from a turbojet engine whose
blades were coated with two different coating materials (silicon
dioxide and boric oxide) by adding silicone oil and tributyl borate to
the engine fuel. The very thin coatings (approximately 0.001 in.) that
formed on the blades produced a negligible effect on the turbine-blade
transient temperature response. With the analysis discussed here, it
was possible to predict the turbine rotor-blade temperature response
with a maximum error of 40 F. |
| 620. |
Investigation of water-spray
cooling of turbine blades in a turbojet engine ( March 10,
1953) by Freche, John C Stelpflug, William J [46 pages; 2 MB] |
|
Abstract: An analytical and experimental
investigation was made with a J33-A-9 engine to determine the
effectiveness of spray cooling as a means of increasing thrust by
permitting engine operation at inlet-gas temperatures and speeds above
rated. With the assumption of adequate spray cooling at a
coolant-to-gas flow ratio of 3 percent, calculations for the sea-level
static condition indicated a thrust may be achieved by engine operation
at an inlet-gas temperature of 2000 degrees F and an overspeed of 10
percent. Of the water-injection configurations investigated
experimentally, those located in the inner ring of the stator diaphragm
provided the best cooling at rated engine speed. |
| 621. |
Effect of fuel-air ratio
concentration in combustion zone on combustion performance of a 16-inch
ram-jet engine ( April 13, 1953) by Dangle, E E
Cervenka, A J Bahr, D W [25 pages; 0.7 MB] |
|
Abstract: The results of fuel-air ratio and
temperature surveys made in the flame stabilizing zone of a 16-inch
ram-jet combustor indicated that the distribution of combustible
mixture immediately downstream of a flame holder should be mechanically
controlled if a preferred mixture composition is to be maintained in
that zone. A sloping-baffle combustor configuration gave combustion
efficiencies of 90 percent or greater over a range of fuel-air ratios
from 0.010 to 0.045. |
| 622. |
Investigation of liquid
fluorine : liquid ammonia propellant combination in a 100-pound-thrust
rocket engine ( July 03, 1953) by Rothenberg, Edward A
Douglass, Howard W [32 pages; 1 MB] |
|
Abstract: No Abstract Available |
| 623. |
Experimental investigation of
air-cooled turbine blades in turbojet engine XIII : endurance
evaluation of several protective coatings applied to turbine blades of
nonstrategic steels ( July 16, 1953) by Bartoo, Edward R
Clure, John L [41 pages; 1.7 MB] |
|
Abstract: No Abstract Available |
| 624. |
Magnesium-slurry combustion
performance in 6.5-inch-diameter ram-jet engine mounted in
connected-pipe facility ( August 05, 1953) by
Branstetter, J Robert Gibbs, James B Kaufman, Warner B [64 pages; 2 MB]
|
|
Abstract: No Abstract Available |
| 625. |
Altitude evaluation of several
afterburner design variables on a J47-GE-17 turbojet engine (
October 23, 1953) by Walker, Curtis L Braithwaite, Willis M Sivo,
Joseph N [56 pages; 1.9 MB] |
|
Abstract: No Abstract Available |
| 626. |
Preliminary investigation of
several root designs for cermet turbine blades in turbojet engine II :
root design alterations ( October 13, 1953) by Meyer, A
J , Jr Deutsch, G C Morgan, W C [35 pages; 1.4 MB] |
|
Abstract: No Abstract Available |
| 627. |
Experimental investigation of
several water-injection configurations for turbine-blade spray cooling
in a turbojet engine ( October 08, 1953) by Freche, John
C Mckinnon, Roy A [38 pages; 1.6 MB] |
|
Abstract: No Abstract Available |
| 628. |
A theoretical analysis of the
distortion of fuel-spray-particle paths in a helicopter ram-jet engine
due to centrifugal effects ( April 07, 1953) by Katzoff,
S Smith, Samuel L , III [45 pages; 1 MB] |
|
Abstract: No Abstract Available |
| 629. |
Engineering method of ram-jet
thrust determination based on experimentally obtained combustor
parameters ( August 13, 1953) by Dettwyler, H Rudolph
Faget, Maxime A [45 pages; 1.1 MB] |
|
Abstract: No Abstract Available |
| 630. |
An engineering method for the
determination of aeroelastic effects upon the rolling effectiveness of
ailerons on swept wings ( November 30, 1953) by Strass,
H Kurt Stephens, Emily W [83 pages; 2 MB] |
|
Abstract: No Abstract Available |
| 631. |
Comparison of the performance
of a helicopter-type ram-jet engine under various centrifugal loadings
( October 07, 1953) by Radin, Edward J Carpenter, Paul J [22
pages; 0.6 MB] |
|
Abstract: No Abstract Available |
| 632. |
Preflight tests and flight
performance of a 6.5-inch diameter ram-jet engine ( November
02, 1953) by Hinners, Arthur H , Jr Foland, Douglas, H [57 pages;
1.5 MB] |
|
Abstract: No Abstract Available |
| 633. |
The attenuation characteristics
of four specially designed mufflers tested on a practical engine setup
( May 1953) by Stokes, George M Davis, Don D , Jr [31 pages; 1
MB] |
|
Abstract: Attenuation characteristics of four
different resonator mufflers were determined in both cold tests and
engine field tests and compared with the theoretical calculations.
These mufflers were specifically designed for a helicopter.
Engine-exhaust sound pressures, temperatures, and noise levels from the
helicopter were measured. The experimental muffler cold tests indicated
close a agreement with theory, whereas the engine tests indicated some
discrepancies. Test results show the usefulness of the theoretical
equation used for predicting muffler attenuation characteristics. |
| 634. |
Effect of engine and control
limits on steady-state and transient performance of turbojet engine
with variable-area exhaust nozzle ( 1953) by Vasu,
George., Hinde, William L. [47 pages; 2.6 MB] |
|
Abstract: (abstract not available) |
| 635. |
Analysis of the turbojet engine
for propulsion of supersonic fighter airplanes / David S. Gabriel,
Richard P. Krebs, E.Clinton Wilcox, Stanley L.Koutz ( 1953)
by Gabriel, David S., Krebs, Richard P., Wilcox, E. Clinton., Koutz,
Stanley L. [87 pages; 3.8 MB] |
|
Abstract: An analytical investigation was made of
two supersonic interceptor type airplanes to determine the most
desirable turbojet engine characteristics for this application The
airplanes were designed differently primarily because of the amount of
subsonic flight incorporated in the flight plan--one flight having none
and the other, a cruise radius of 400 nautical miles. Several power
plant design variables were varied independently to determine the
effect of changes in each parameter on airplane performance. These
parameters included compressor pressure ratio, compressor efficiency,
turbine-inlet temperature, afterburner temperature, engine specific
weight, and air-handling capacity. The effects of using a
convergent-divergent exhaust nozzle and of changing the design flight
Mach number were also investigated. |
| 636. |
Effect of rotor-and
stator-blade modifications on surge performance of an 11-stage
axial-flow compressor I :original production compressor of XJ40-WE-6
engine ( 1953) by Finger, Harold B., Essig, Robert H.,
Conrad, E. William. [46 pages; 1.8 MB] |
|
Abstract: An investigation to increase the
compressor surge-limit pressure ratio of the XJ40-WE-6 turbojet engine
at high equivalent speeds was conducted at the NACA Lewis altitude wind
tunnel. This report evaluates the compressor modifications which were
restricted to (1) twisting rotor blades (in place) to change blade
section angles and (2) inserting new stator diaphragms with different
blade angles. Such configuration changes could be incorporated quickly
and easily in existing engines at overhaul depots. It was found that
slight improvements in the compressor surge limit were possible by
compressor blade adjustment. However, some of the modifications also
reduced the engine air flow and hence penalized the thrust. A mixer
assembly designed and supplied by the engine manufacturer was used at
the compressor outlet and improved the surge limit with no appreciable
thrust penalty. |
| 637. |
Altitude performance
characteristics of the J47-25 turbojet engine :data presentation
( 1953) by Renas, Paul E., Jansen, Emmert T. [35 pages; 1.4 MB] |
|
Abstract: The altitude performance of the J47-25
turbojet engine operating with a fixed-area exhaust nozzle was
determined over a range of engine-inlet Reynolds numbers corresponding
to altitudes from 18,000 to 54,000 feet and flight Mach numbers from
0.50 to 1.10. Reducing the engine-inlet Reynolds number resulted in a
reduction in corrected air flow but had essentially no effect on
corrected exhaust-gas total temperature, corrected fuel flow, and
engine pumping characteristics for a range of Reynolds number indices
from 0.80 to 0.30. The corrected jet thrust parameter generalized
throughout the range of engine-inlet Reynolds numbers investigated. At
a given corrected engine speed with critical pressure ratio existing in
the exhaust nozzle, increasing the engine-inlet ram-pressure ratio from
1.0 to 1.25 decreased the corrected exhaust-gas temperature. Further
increases in ram-pressure ratio had no effect on the exhaust-gas
temperature. |
| 638. |
Altitude investigation of
XJ34-WE-32 engine performance without electronic control (
1953) by Bloomer, Harry E., Walker, William J., Pantages, George
L. [41 pages; 2 MB] |
|
Abstract: An investigation was conducted in the
NACA Lewis altitude wind tunnel to evaluate the performance
characteristics of an XJ34-WE-32 turbojet engine which was equipped
with an afterburner, a variable-area exhaust nozzle, and an integrated
electronic control. The data were obtained with the afterburner and
electronic control inoperative. Performance data were obtained at
altitudes from 5000 to 55,000 feet and flight Mach numbers from 0.28 to
1.06 for a complete range of operable engine speeds at each of four
fixed positions of the variable-area exhaust nozzle. |
| 639. |
Altitude performance
investigation of two single-annular type combustors and the prototype
J40-WE-8 turbojet engine combustor with various combustor-inlet air
pressure profiles ( 1953) by Sobolewski, Adam E.,
Miller, Robert R., McAulay, John E. [48 pages; 2.3 MB] |
|
Abstract: Data obtained for three single-annular
type combustors over a range of engine speeds at an altitude of 30,000
feet and flight Mach number of 0.62 indicated that changes in combustor
hole geometry and combustor-inlet air-pressure profiles affected the
combustor-outlet temperature profile and the combustor pressure-loss
coefficient but had no discernible effect on combustion efficiency.
Performance data for the prototype J40-WE-8 turbojet-engine combustor
were obtained over a range of altitudes from 15,000 to 55,000 feet and
flight Mach numbers from 0.17 to 0.99. A good correlation was obtained
when combustion efficiency was presented as a function of a combustion
parameter and engine fuel-air ratio. |
| 640. |
Preliminary evaluation of
turbine performance with variable-area turbine nozzles in a turbojet
engine ( 1953) by Campbell, Carl E., Welna, Henry J. [35
pages; 1.6 MB] |
|
Abstract: The performance of a two-stage turbine
with variable-area first-stage turbine nozzles was determined in the
NACA Lewis altitude wind tunnel over a range of simulated altitudes
from 15,000 to 44,000 feet and engine speeds from 50 to 100 percent of
rated speed. The variable-area turbine nozzles were found to be
mechanically reliable and to have negligible leakage losses. Increasing
the turbine-nozzle-throat area from 1.15 to 1.67 square feet increased
the corrected turbine gas flow or effective turbine nozzle area about
10 percent. At a given corrected turbine speed and turbine pressure
ratio, changing the turbine nozzle area from 1.30 to 1.67 square feet
lowered the turbine efficiency 3 or 4 percent. The effect of increasing
the turbine nozzle area from 1.15 to 1.67 square feet (decreasing the
turning angle about 7-1/2 degrees) would be to lower the turbine
efficiency about 5 or 6 percent. |
| 641. |
Altitude wind tunnel
investigation of the prototype J40-WE-8 turbojet engine without
afterburner ( 1953) by McAulay, John E., Kaufman, Harold
R. [54 pages; 2.7 MB] |
|
Abstract: An investigation was conducted in the
Lewis altitude wind tunnel to evaluate the performance characteristics
of the prototype J40-WE-8 turbojet engine without afterburner. Data
were obtained with an electronic control operative and inoperative. The
performance data were obtained at altitudes from 15,000 to 60,000 feet
and flight Mach numbers of 0.17 to 1.68. At corrected engine speeds of
7000 rpm and above, an increase in altitude resulted in an increase in
correct net thrust and had no effect on corrected air flow. A method is
presented to define the effect of changes in engine operating and
flight conditions on the pumping and air-flow characteristics and the
combustion efficiency. |
| 642. |
Preliminary investigation in
J33 turbojet engine of several root designs for ceramal turbine blades
( 1953) by Deutsch, George C., Meyer, Andre J., Jr., Morgan,
William C. [26 pages; 1.1 MB] |
|
Abstract: The practicability of using ceramals
with comparatively low strategic material content for the blades of
aircraft turbines was determined in an experimental investigation. Four
blade root configurations were examined. The most favorable results
were obtained for ceramal turbine blades with single serration
interlock and dovetail root configurations. Six of the interlock type
were operated in a J33-A-33 engine for 68 hr, 23 min at rated service
speed and six of the dovetail type were operated for 58 hr, 28 min at
rated speed. This result confirms the conclusions of previous static
design studies. |
| 643. |
Orthotoluidine and
triethylamine in rocket engine applications ( 1953) by
Ladanyi, Dezso J. [26 pages; 1.2 MB] |
|
Abstract: The literature pertaining to the use of
orthotoluidine and triethylamine in rocket propellant combinations was
surveyed and summarized with particular emphasis on ignition delay
investigations and fuel mixture applications. In addition, experimental
ignition delay determinations of two orthotoluidine-triethylamine
mixtures (1:1 and 3:7 by volume) and a low-freezing-point red fuming
nitric acid were conducted at simulated altitude conditions utilizing a
small-scale rocket engine of approximately 50 pounds thrust. The delays
varied almost linearly from about 12 milliseconds at 120 degrees F to
about 28 milliseconds at minus 70 degrees F for both propellant
combinations. At minus 95 degrees F, the ignition delays for the 1:1
and 3:7 fuel blends were about 101 and 29 milliseconds, respectively.
Experiments at pressure altitudes of about 90,000 feet at the two
temperature extremes indicated no significant effect of low initial
ambient pressure on ignition delay. |
| 644. |
Altitude investigation of
several afterburner configurations for the J40-WE-8 turbojet engine
( 1953) by Conrad, E. William., Campbell, Carl E. [52 pages; 2.3
MB] |
|
Abstract: An investigation was conducted in the
Lewis altitude wind tunnel to evaluate the performance and operational
characteristics of the J40-WE-8 afterburner. A brief program of minor
modifications to the flame holder, diffuser, and fuel system was
undertaken to improve at a burner-inlet pressure level of 620 pounds
per square foot. At this pressure level, modifications to the fuel
system resulted in an increase in maximum net thrust from 1500 to 1600
pounds and a reduction in specific fuel consumption in the
stoichiometric region from 3.70 to 3.15 pounds of fuel per hour per
pound of net thrust. However, these fuel system modifications also
resulted in buzzing combustion under certain operation conditions. |
| 645. |
Altitude investigation of
thrust augmentation using water-alcohol injection into the combustion
chambers of an axial-flow turbojet engine ( 1953) by
Jansen, E. T., Renas, P. E. [30 pages; 1.3 MB] |
|
Abstract: An investigation was conducted in an
altitude test chamber using water-alcohol injection into the combustion
chambers of an axial-flow turbojet engine. Data were obtained at a
flight Mach number of 0.8 for a range of altitudes from 30,000 to
50,000 feet over a range of liquid-air ratios from 0 to 0.10 and for a
range of exhaust-nozzle areas from 100 percent to 93.7 percent of the
standard nozzle area. Employing a continuously variable-area exhaust
nozzle and operating at limiting turbine-outlet temperature, net thrust
augmentation ratios of 1.25, 1.23, and 1.21 were obtained at a
liquid-air ratio of 0.10 for altitudes of 30,000, 40,000, and 50,000
feet, respectively. Operation with the standard nozzle area and with a
liquid-air ratio of 0.10 resulted in a variance of net thrust from 1.14
to 1.195 as the altitude was increased from 30,000 to 50,000 feet. The
use of 10,000 gallons of water-alcohol mixture in 7.5 hours of engine
running time resulted in no noticeable engine structural
deterioriation. |
| 646. |
Component and over-all
performance evaluation of a J47-GE-25 turbojet engine over a range of
engine-inlet Reynolds number indices ( 1953) by Walker,
Curtis L., Braithwaite, Willis M., Fenn, David B. [75 pages; 2.8 MB] |
|
Abstract: An investigation was conducted in an
altitude test chamber to evaluate the performance of an axial-flow
turbojet engine over a range of engine-inlet Reynolds number indices.
The range of Reynolds number indices investigated provided data which
were applicable over a range of flight conditions, for example,
altitudes from 15,000 to 55,000 feet at a flight Mach number of 0.7.
Secondary effects of exhaust-nozzle flow coefficient, air-flow leakage,
and inlet temperature which should be considered before analyzing the
effect of variations in engine-inlet Reynolds number index are
presented. In general, the effect of reducing Reynolds number index was
to lower compressor efficiency and air flow with a resultant shift in
the compressor map and rematching of compressor with turbine. There was
only a slight effect of Reynolds number index variation on the turbine
performance. Several minor design modifications proposed by the
manufacturer (designated as a block change) did not produce any
measurable improvement in engine performance. |
| 647. |
Behavior of forged S-816
turbine blades in steady-state operation of J33-9 turbojet engine with
stress-rupture and metallographic evaluations / By F. B.Garrett, C. A.
Gyorgak, and J. W. Weeton ( 1953) by Garrett, Floyd B.,
Gyorgak, Charles A., Weeton, John Waldemar. [31 pages; 1.3 MB] |
|
Abstract: An investigation was conducted to
determine the behavior of recently produced, forged S-816 turbine
blades in a full-scale turbojet engine, and in particular, the scatter
in performance of the alloy. The turbine blades were operated as
continuously as possible at a temperature of 1500 degrees F and a
centrifugal stress of 21,500 pounds per square inch. The operating
lives of the turbine blades varied from 181 to 539 hours, a range of
358 hours. Stress-rupture properties of specimens cut from blade
airfoils also varied considerably, as much as 1257 hours at 20,000
pounds per square inch and 1500 degrees F. Since the variability of
scatter of stress-rupture data is greater than that of blade
performance, the scatter is probably caused by variations in the
properties of the forged blades rather than by variations caused by
engine operation or installation of the blades. Metallographic
examinations were made to determine possible causes of the scatter and
although numerous differences in microstructures of blades were found,
no consistent tendencies were observed and the findings did not permit
an explanation of the scatter of blade performance. The results of the
metallographic examinations and of the physical tests indirectly
indicated variables in the fabricating method caused the scatter in
properties. |
| 648. |
Turbojet-engine thrust
augmentation at altitude by combined ammonia injection into the
compressor inlet and afterburning ( 1953) by Useller,
James W., Fenn, David B., Harp, James L., Jr. [37 pages; 1.6 MB] |
|
Abstract: An experimental investigation was
conducted on an axial-flow turbojet engine operating at simulated
transonic flight conditions at an altitude of 35,000 feet to determine
the magnitude of the thrust augmentation and to ascertain the
operational characteristics of a combined augmentation system. This
system included the use of a high-performance afterburner (operating at
approximately stoichiometric condition) and the introduction of liquid
anhydrous ammonia into the compressor inlet (ammonia-air ratios from 0
to 0.55). The maximum augmented net thrust ratio obtained, 2.13,
resulted from a combination of a stoichiometric condition in the
afterburner and the introduction of liquid ammonia into the compressor
inlet to produce an ammonia-air ratio of 0.045. Maximum afterburner
combustion efficiency and temperature occurred while the afterburner
was operating stoichiometrically both with and without the ammonia
injection. |
| 649. |
Adhesive and protective
characteristics of ceramic coating A-417 and its effect on engine life
of forged Refractaloy-26 (AMS 5760) and cast stellite 21 (AMS 5385)
turbine blades ( 1953) by Garrett, Floyd B., Gyorgak,
Charles A. [23 pages; 0.9 MB] |
|
Abstract: The adhesive and protective
characteristics of National Bureau of Standards Coating A-417 were
investigated, as well as the effect of the coating on the life of
forged Refractaloy 26 and cast Stellite 21 turbine blades. Coated and
uncoated blades were run in a full-scale J33-9 engine and were
subjected to simulated service operations consisting of consecutive
20-minute cycles (15 min at rated speed and approximately 5 min at
idle). The ceramic coating adhered well to Refractaloy 26 and Stellite
21 turbine blades operated at 1500 degrees F. The coating also
prevented corrosion of the Refractaloy 26, a corrosion-sensitive
nickel-base alloy, and of the Stellite 21, a relatively
corrosion-resistant cobalt-base alloy. Although the coating prevented
corrosion of both alloys, it had no apparent effect on blade life. |
| 650. |
Some measurements of noise from
three solid-fuel rocket engines ( Dec 1954) by Leslie W.
Lassiter, Robert H. Heikotter [22 pages; 0.6 MB] |
|
Abstract: A systematic investigation of the sound
field of a 1,000-pound-thrust solid-fuel rocket was made and data on
two other rockets, of 900 and 5,500 pounds of thrust, were obtained at
a few isolated field points. |
| 651. |
A method of measuring jet
thrust of turbojet engines in flight installations ( January
21, 1954) by Sivo, Joseph N Fenn, David B [20 pages; 0.6 MB] |
|
Abstract: Measurement of the jet thrust of a
turbojet engine in flight becomes more difficult as the number and
complexity of the engine components increase. It is desirable,
therefore, that a general correlation of jet thrust be developed which
is applicable to a simple direct reading thrustmeter. In view of this
need a correlation is presented which is independent of flight
conditions and applicable to both non-afterburning and afterburning
engines equipped with nonejector type fixed- and variable-area
convergent exhaust nozzles. The general equation used in this
correlation was derived from the theoretical jet-thrust equation for a
choked convergent nozzle. The data used to verify the correlation were
obtained over a range of altitudes from 10,000 to 54,000 feet and a
range of flight Mach numbers from 0.4 to 1.1. A thrustometer based on
this equation was installed on an afterburning turbojet engine equipped
with a fixed area convergent exhaust nozzle. The results indicated that
a meter based on this correlation would be applicable to a flight
installation and that the probable error in thrust measurement would be
approximately + or -1.5 percent provided the exhaust-nozzle thrust
coefficient is known. |
| 652. |
Starting characteristics and
combustion performance of magnesium slurry in 6.5-inch-diameter ram-jet
engine mounted in connected-pipe facility ( January 28, 1954)
by Gibbs, James B [26 pages; 1 MB] |
|
Abstract: The starting characteristics and
combustion performance of slurry type fuels, consisting of 50 percent
magnesium powder in a hydrocarbon carrier, have been investigated in a
flight-type, 6.5-inch-diameter ram-jet engine in a connected-pipe
facility. Quick, dependable starting of the engine was obtained by the
use of a disk which blocked part of the combustor area downstream of
the flame holder. Acceptable performance was achieved with a short
fuel-air mixing length by the development of a fuel-distribution
control sleeve. |
| 653. |
Summary of free-flight
performance of a series of ram-jet engines at Mach numbers from 0.80 to
2.20 ( February 11, 1954) by North, Warren J [38 pages;
1.2 MB] |
|
Abstract: Data obtained from the NACA
air-launched ram-jet program are summarized with emphasis placed upon
the transonic propulsive thrust potential of the engines. Data are
presented for boosted and non-boosted engine configurations which
incorporate a single-oblique-shock or double-oblique-shock diffuser
designed for critical inlet operation at flight Mach numbers of 1.8 and
2.4, respectively. The engines are evaluated in terms of flight Mach
number, mass-flow ratio, diffuser pressure recovery, combustion-chamber
heat release, propulsive thrust, external drag, and specific impulse.
From specific impulse considerations, it appears that for some
air-launched missile applications the self-accelerating supersonic ram
jet may have a lower gross weight than a rocket-boosted ram jet. |
| 654. |
Performance of two air-cooled
turbojet engines determined analytically from engine component
performance for a range of cooling-air weight flows ( February
17, 1954) by Ziemer, Robert R Schafer, Louis J JR Heaton, Thomas
R [40 pages; 1.5 MB] |
|
Abstract: No Abstract Available |
| 655. |
Exploratory engine test of
transpiration-cooled turbine-rotor blade with wire-cloth shell
( 1954) by Donoughe, Patrick L Diaguila, Anthony J [19 pages; 0.8
MB] |
|
Abstract: Engine tests were made on a
transpiration-cooled blade that was fabricated from an internal
load-carrying member with an external surface of wire cloth. After
operation in the engine, some damage was noted at the tip region of the
trailing edge of the blades. On other sections of the blade, the wire
cloth did not appear greatly overheated, and it appeared that
satisfactory chordwise temperature distribution was provided by
orifices in the blade base. |
| 656. |
Investigation of conical
subsonic diffusers for ram-jet engines ( March 15, 1954)
by Farley, John M Welna, Henry J [41 pages; 1.5 MB] |
|
Abstract: The efficiency of a 30 degree conical
diffuser was improved as much as 20 percent and separation was
eliminated by the use of vortex generators. The use of splitter cones
gave only small efficiency gains, but relatively uniform
diffuser-outlet velocity profiles were obtained with the better
designs. A configuration which incorporated both vortex generators and
a splitter cone gave efficiencies higher than those obtained with any
other splitter-cone configuration and also higher than those obtained
when the same vortex generators were used without the splitter cone.
Moderate diffuser-efficiency increases were obtained with guide vanes;
however, in all cases combustion occurred in the vane wakes. |
| 657. |
Evaluation of a compressor
bleed system for RIM cooling the turbine wheel of a turbojet engine
( March 22, 1954) by Morse, C R Kemp, R H [21 pages; 0.6 MB] |
|
Abstract: No Abstract Available |
| 658. |
Photographic study of rotary
screaming and other oscillations in a rocket engine ( 1954)
by Male, Theodore Kerslake, William R Tischler, Adelbert O [38 pages;
1.9 MB] |
|
Abstract: No Abstract Available |
| 659. |
Experimental performance of
liquid fluorine-liquid ammonia propellant combination in
1000-pound-thrust rocket engines ( May 13, 1954) by
Douglass, Howard W [33 pages; 1.2 MB] |
|
Abstract: No Abstract Available |
| 660. |
Effect of mechanically induced
sinusoidal air-foil oscillations on operation of a ram-jet engine
( June 16, 1954) by Dangle, E E Cervenka, A J Perchonok, Eugene
[23 pages; 0.9 MB] |
|
Abstract: No Abstract Available |
| 661. |
An evaluation of turbojet
engine thrust control by exhaust-nozzle-area modulation and
compressor-inlet throttling ( August 02, 1954) by Harp,
James L , Jr Velie, Wallaace W Mallett, William [18 pages; 0.6 MB] |
|
Abstract: No Abstract Available |
| 662. |
A method for prevention of
screaming in rocket engines ( August 19, 1954) by Male,
Theodore Kerslake, William R [24 pages; 1.2 MB] |
|
Abstract: No Abstract Available |
| 663. |
Altitude investigation of
20-inch-diameter ram-jet engine with annular-piloted combustor
( August 27, 1954) by Henzel, James G Trout, Arthur M [27 pages;
0.8 MB] |
|
Abstract: No Abstract Available |
| 664. |
Performance of a 16-inch
ram-jet engine with a can-type combustor at Mach numbers of 1.5 to 2.16
( August 27, 1954) by Hearth, Donald P Perchonok,
Eugene [31 pages; 0.9 MB] |
|
Abstract: No Abstract Available |
| 665. |
Drag data for 16-inch-diameter
ram-jet engine with double-cone inlet in free flight at Mach numbers
from 0.7 to 1.8 ( October 25, 1954) by Jones, Merle L
Rabb, Leonard Simpkins, Scott H [53 pages; 1.5 MB] |
|
Abstract: No Abstract Available |
| 666. |
Preliminary report of
experimental investigation of ram-jet controls and engine dynamics
( October 25, 1954) by Vasu, G Wilcox, F A Himmel, S C [71 pages;
2.3 MB] |
|
Abstract: No Abstract Available |
| 667. |
Investigation to Mach number
2.0 of shock-positioning control systems for a variable-geometry inlet
in combination with a J34 turbojet engine ( December 20, 1954)
by Leissler, L Abbott Nettles, J Cary [40 pages; 1.4 MB] |
|
Abstract: No Abstract Available |
| 668. |
Flight and preflight evaluation
of an automatic thrust-coefficient control system in a twin-engine
ram-jet missile ( January 22, 1954) by Dettwyler, H
Rudolph Trout, Otto F JR [39 pages; 1.1 MB] |
|
Abstract: No Abstract Available |
| 669. |
The effects of operating
propellers on the longitudinal characteristics at high subsonic speeds
of a four-engine tractor airplane configuration having a wing with 40
degrees of sweepback and an aspect ratio of 10 ( January 07,
1954) by Sutton, Fred B Demele, Fred A [108 pages; 2.8 MB] |
|
Abstract: No Abstract Available |
| 670. |
Effects of operating propellers
on the wing-surface pressures of a four-engine tractor airplane
configuration having a wing with 40 degrees of sweepback (
April 23, 1954) by Boltz, Frederick W Kolbe, Carl D [134 pages;
4.7 MB] |
|
Abstract: No Abstract Available |
| 671. |
The effect of lip shape on a
nose-inlet installation at Mach numbers from 0 to 1.5 and a method for
optimizing engine-inlet combinations ( May 07, 1954) by
Mossman, Emmet A Anderson, Warren E [50 pages; 1.2 MB] |
|
Abstract: No Abstract Available |
| 672. |
Flight Investigation of Engine
Nacelles and Wing Vertical Position on the Drag of a Delta-Wing
Airplane Configuration from Mach Number 0.8 to 2.0 ( 1954)
by Joseph H. Judd (Langley Aeronautical Laboratory, Langley Field, Va.)
[41 pages; 1 MB] |
|
Abstract: No Abstract Available |
| 673. |
Theoretical and Experimental
Investigation of Mufflers with Comment on Engine-Exhaust Muffler Design
( 1954) by Don D. Davis, Jr., George M. Stokes,
Dewey Moore, George L. Stevens, Jr. [51 pages; 5.9 MB] |
|
Abstract: Equations are presented for the
attenuation characteristics of single-chamber and multiple-chamber
mufflers of both the expansion-chamber and resonator types, for tuned
side-branch tubes, and for the combination of an expansion chamber with
a resonator. Experimental curves of attentuation plotted against
frequency are presented for 77 different mufflers with a
reflection-free tailpipe termination, and the resuslts are compared
with theory. The experiments were made at room temperature without
flow; the sound source was a loud speaker. A method is given for
including the tailpipe reflections in the calculations. Experimental
attenuation curves are presented for four different muffler-tailpipe
combinations, and results are compared with theory. The application of
the theory to the design of engine-exhaust mufflers is discussed, and
charts are included for the assistance of the designer. Noise spectrums
are presented for a helicopter with each of the four muffler-tailpipe
combinations installed. These spectrums are compared with the noise
spectrum of the unmuffled helicopter. The results show that the overall
noise level of the helicopter was reduced significantly by even the
smallest of the four mufflers tested. |
| 674. |
Analog study of interacting and
noninteracting multiple-loop control systems for turbojet engines
( 1955) by George J. Pack, W. E. Phillips, Jr. [14 pages; 1.2 MB]
|
|
Abstract: The results of an analog investigation
of several turbojet-engine control configurations is presented in this
report. Both proportional and proportional-plus-integral controllers
were studied, and compensating terms for engine interaction were added
to the control system. Data were obtained on the stability limits and
the transient responses of these various configurations. Analytical
expressions in terms of the component transfer functions were developed
for the configurations studied, and the optimum form for the
compensation terms was determined. It was found that the addition of
the integral term, while making the system slower and more oscillatory,
was desirable in that it made the final values of the system parameters
independent of source of disturbance and also eliminated droop in these
parameters. Definite improvement in system characteristics resulted
from the use of proper compensation terms. At comparable gain points
the compensated system was faster and more stable. Complete
compensation eliminated engine interaction, permitting each loop to be
developed to an optimum point independently. |
| 675. |
Analysis of the horizontal-tail
loads measured in flight on a multiengine jet bomber ( Sep
1955) by William S. Aiken, Bernard Wiener [71 pages; 2.2 MB] |
|
Abstract: Horizontal-tail loads were measured in
gradual and abrupt longitudinal maneuvers on two configurations of a
four-engine jet bomber. The results obtained have been analyzed to
determine the flight values of the coefficients important in
calculations of horizontal-tail loads. |
| 676. |
Preliminary analysis of
performance of turbojet engines used as pumps for boundary-layer
control ( August 16, 1955) by Conrad, E William [22
pages; 0.7 MB] |
|
Abstract: No Abstract Available |
| 677. |
Experimental study of
shock-positioning method of ram-jet-engine control ( August
29, 1955) by Hurrell, Herbert G Vasu, George Dunbar, William R
[72 pages; 3 MB] |
|
Abstract: No Abstract Available |
| 678. |
An experimental evaluation of
several design variations of hollow turbine blades for expendable
engine application ( February 23, 1955) by Morgan, W C
Kemp, R H [34 pages; 1 MB] |
|
Abstract: No Abstract Available |
| 679. |
Inlet-air distortion effects on
stall, surge, and acceleration margin of a turbojet engine equipped
with variable compressor inlet guide vanes ( October 04, 1955)
by Harry, David P , III Lubick, Robert J [50 pages; 3.7 MB] |
|
Abstract: No Abstract Available |
| 680. |
Application of oblique-shock
sensing system to ram-jet-engine flight Mach number control (
March 03, 1955) by Wilcox, Fred A Hearth, Donald P [30 pages; 1.1
MB] |
|
Abstract: No Abstract Available |
| 681. |
Preliminary investigation of
several root designs for cermet turbine blades in turbojet engine III :
curved-root design ( December 28, 1955) by Pinkel,
Benjamin Deutsch, George C Morgan, William C [18 pages; 0.5 MB] |
|
Abstract: Stresses om tje root fastenings of
turbine blades were appreciably reduced by redesign of the root. The
redesign consisted in curving the root to approximately conform to the
camber of the airfoil and elimination of the blade platform. Full-scale
jet-engine tests at rated speed using cermet blades of the design
confirmed the improvement. |
| 682. |
Rocket-engine throttling
( 1955) by Tomazic, William A [23 pages; 1 MB] |
|
Abstract: No Abstract Available |
| 683. |
Some linear dynamics of
two-spool turbojet engines ( Jun 1956) by David Novik
[36 pages; 0.8 MB] |
|
Abstract: General equations for the linear
responses of inner- and outer-spool speed to change in turbine-inlet
temperature and exhaust-nozzle area are derived and evaluated from
hypothetical two-spool-engine characteristics at design speed. |
| 684. |
Investigation of the effect of
impact damage on fatigue strength of jet-engine compressor rotor blades
( Jun 1956) by Albert Kaufman, Andre J. Meyer, Jr.
[26 pages; 0.9 MB] |
|
Abstract: An investigation was undertaken to
determine the effect of type and location of impact damage on the
fatigue strength of jet-engine compressor blades. First-stage
compressor rotor blades from a production engine which had suffered
foreign-object damage were fatigue tested. |
| 685. |
Factors that affect operational
reliability of turbojet engines ( January 31, 1956) by
(Author(s) Not Available) [379 pages; 13.9 MB] |
|
Abstract: The problem of improving operational
reliability of turbojet engines is studied in a series of papers.
Failure statistics for this engine are presented, the theory and
experimental evidence on how engine failures occur are described, and
the methods available for avoiding failure in operation are discussed.
The individual papers of the series are Objectives, Failure Statistics,
Foreign-Object Damage, Compressor Blades, Combustor Assembly, Nozzle
Diaphrams, Turbine Buckets, Turbine Disks, Rolling Contact Bearings,
Engine Fuel Controls, and Summary Discussion. |
| 686. |
Effect of inlet-duct length in
uniform-flow field on turbojet-engine operation ( April 11,
1956) by Lubick, Robert J Chelko, Louis J Wallner, Lewis E [27
pages; 0.7 MB] |
|
Abstract: No Abstract Available |
| 687. |
Weight-flow and thrust
limitations due to use of rotating combustors in a turbojet engine
( August 17, 1956) by Lezberg, Erwin A Blackshear, Perry L , Jr
Rayle, Warren D [31 pages; 0.9 MB] |
|
Abstract: No Abstract Available |
| 688. |
Effects of rocket-armament
exhaust gas on the performance of a supersonic-inlet
J34-turbojet-engine installation at Mach 2.0 ( February 20,
1956) by Beheim, Milton, A Evans, Phillip J [25 pages; 0.7 MB] |
|
Abstract: No Abstract Available |
| 689. |
Dynamics of a supersonic inlet
with adjustable bypass in combination with a J34 turbojet engine
( March 23, 1956) by Wilcox, Fred Whalen, Paul [28 pages; 0.9 MB]
|
|
Abstract: No Abstract Available |
| 690. |
Effect of fuels on screaming in
200-pound-thrust liquid-oxygen - fuel rocket engine ( June 22,
1956) by Pass, Isaac Tischler, Adelbert O [27 pages; 0.8 MB] |
|
Abstract: No Abstract Available |
| 691. |
Effect of variable-position
inlet guide vanes and interstage bleed on compressor performance of a
high-pressure-ratio turbojet engine ( December 28, 1956)
by Huntley, S C Braithwaite, Willis M [28 pages; 1.5 MB] |
|
Abstract: Increased guide-vane turning resulted
in poorer overall performance, the decrease being greatest at the
highest rotor speed. Rotating stall originating at the tips of the
first stage correlated with the knee in the stall-limit line.
Increasing guide-vane turning shifted the first-stage stall-free
performance and the knee in the stall-limit line to a lower engine
speed. Opening the interstage bleed reduced the minimum rotor speed at
which stall-free performance of the first stage was possible and tended
to eliminate the knee in the stall-limit line. |
| 692. |
Analysis of limitations imposed
on one-spool turboprop-engine designs by compressors and turbines at
flight mach numbers of 0, 0.6, and 0.8 ( December 06, 1956)
by Cavicchi, Richard H [67 pages; 2 MB] |
|
Abstract: Turbine centrifugal stress is a
limiting factor for all flight conditions studied. This stress is more
severe for sea-level operations than for subsonic flight at the
tropopause. Turbines designed for a stress of 30,000 psi are capable of
driving a light, compact, high-spedd compressor but only at high values
of specific fuel consumption. An increase in turbine-inlet temperature
is accompanied by an increase in turbine centrifugal stress. If
stresses in excess of 50,000 psi can be tolerated, compressor
aerodynamics may become a primary limitation. |
| 693. |
Preliminary investigation of
Guy alloy as a turbojet-engine bucket material for use at 1650 degrees
F ( November 29, 1956) by Signorelli, R A Johnston, J R
Weeton, J W [23 pages; 0.8 MB] |
|
Abstract: As-cast buckets of Guy alloy, a cast
nickel-base material, were run in a J33-9 turbojet engine for cycles of
15 minutes at rated speed and 5 minutes at idle speed. Stress rupture,
impace and engine-performance data indicate that Guy alloy may be
considered for bucket use at a temperature of 1650 degrees F. Ductility
and impact strength of Guy alloy is limited but appears to be adequate
for bucket applications. |
| 694. |
A survey and evaluation of
flutter research and engineering ( October 05, 1956) by
(Author(s) Not Available) [57 pages; 3.7 MB] |
|
Abstract: No Abstract Available |
| 695. |
Aerodynamic principles for the
design of jet-engine induction systems ( February 27, 1956)
by Davis, Wallace F Scherrer, Richard [188 pages; 11.9 MB] |
|
Abstract: No Abstract Available |
| 696. |
Analysis of ram-jet engine
performance including effects of component changes ( October
29, 1956) by Weber, Richard J Luidens, Roger W [47 pages; 1.6 MB]
|
|
Abstract: Calculated design-point performance of
ram-jet engines using JP-4 fuel is presented for a wide range of engine
total-temperature ratios and combustion-chamber-inlet Mach numbers for
flight numbers from 1.5 to 4.0. The results include engine thrust,
drag, fuel consumption, and area ratios. Data are also presented to
illustrate the sensitivity of the results to variations in the assumed
component parameters. A brief comparison is included between fixed-and
variable-geometry engines. |
| 697. |
Performance of a blunt-lip side
inlet with ramp bleed, bypass, and a long constant-area duct ahead of
the engine : Mach number 0.66 and 1.5 to 2.1 ( December 28,
1956) by Allen, John L [56 pages; 1.6 MB] |
|
Abstract: Unsteady shock-induced separation of
the ramp boundary layer was reduced and stabilized more effectively by
external perforations than by external or internal slots. At Mach 2.0
peak total-pressure recovery was increased from 0.802 to 0.89 and
stable mass-flow range was increased 185 percent over that for the
solid ramp. Peak pressure recovery occurred just before instability.
The 7 and one-third-diameter duct ahead of the engine reduced large
total-pressure distortions but was not as successful for small
distortions as obtained with throat bleed. By removing boundary-layer
air the bypass nearly recovered the total-pressure loss due to the long
duct. |
| 698. |
Flight investigation of the
effect of a propulsive jet positioned according to the transonic area
rule on the drag coefficients of a single-engine delta-wing
configuration at Mach numbers from 0.83 to 1.36 ( April 13,
1956) by Judd, Joseph H Falanga, Ralph A [37 pages; 1.4 MB] |
|
Abstract: No Abstract Available |
| 699. |
Model ditching investigation of
a jet transport airplane with various engine installations (
August 20, 1956) by Thomson, William C [28 pages; 0.6 MB] |
|
Abstract: No Abstract Available |
| 700. |
Pressure distributions at Mach
numbers of 1.6 and 1.9 of a conically cambered wing of triangular plan
form with and without pylon-mounted engine nacelles ( 1956)
by Phelps, E. Ray. [38 pages; 1.4 MB] |
|
Abstract: Results are presented of an
experimental investigation of the pressure-distribution characteristics
of a conically cambered wing of triangular plan form with and without
four pylon-mounted engine nacelles. The experimental investigation was
conducted at Mach numbers of 1.6 and 1.9 for Reynolds numbers of 2.9
and 2.6 million, respectively. |
| 701. |
Analytical investigation of the
effect of water injection on supersonic turbojet-engine-inlet matching
and thrust augmentation ( Jan 1957) by Andrew Beke [26
pages; 1.1 MB] |
|
Abstract: An analytical investigation of the
effectiveness of water injection for engine-inlet matching and thrust
augmentation was made at Mach numbers from 1.5 to 2.0. One-dimensional
equations for complete evaporation in a constant-area channel were
applied to a fixed-geometry inlet, and its flight performance was
compared with bypass and translating-spike inlets. |
| 702. |
Propellant vaporization as a
criterion for rocket engine design : calculations of chamber length to
vaporize a single n-heptane drop ( Jul 1957) by Richard
J. Priem [42 pages; 1.4 MB] |
|
Abstract: Calculations based on
droplet-evaporation theory show that for a given combustor length the
percent of fuel mass vaporized can be increased by decreasing the
fuel-drop size and the initial drop velocity, or by increasing chamber
pressure, final gas velocity, and initial fuel temperature. The
analytical results of this study were correlated to give a single curve
of percent of fuel evaporated as a function of the chamber length and
the factors involving these parameters. The calculated results agree
with experimental results if the mass-mean-drop diameters for various
injectors are assumed to be about 100 to 200 microns. |
| 703. |
Calculated and measured
stresses in simple panels subject to intense random acoustic loading
including the near noise field of a turbojet engine ( Sep
1957) by Leslie W. Lassiter, Robert W. Hess [34 pages; 1.2 MB] |
|
Abstract: Flat 2024-T3 aluminum panels measuring
11 inches by 13 inches were tested in the near noise fields of a 4-inch
air jet and turbojet engine. The stresses which were developed in the
panels are compared with those calculated by generalized harmonic
analysis. The calculated and measured stresses were found to be in good
agreement. |
| 704. |
Propellant vaporization as a
criterion for rocket-engine design : calculations using various
log-probability distributions of heptane drops ( Oct 1957)
by Richard J. Priem [31 pages; 1.1 MB] |
|
Abstract: Calculations were made to determine the
vaporization rates of fuel drops in a rocket engine for sprays having
various log-probability distributions of n-heptane drops. The rates
were also calculated for various engine design and operation
parameters. |
| 705. |
Effect of ground proximity on
the aerodynamic characteristics of a four-engine
vertical-take-off-and-landing transport-airplane model with tilting
wing and propellers ( Oct 1957) by William A. Newsom, Jr
[16 pages; 0.6 MB] |
|
Abstract: An investigation has been made to study
the effect of ground proximity on the aerodynamic characteristics of a
four-engine vertical-take-off-and-land transport-airplane model with
tilting wing and propellers. Tests were made with the wing at an angle
of incidence of 90 degrees, the position used for vertical take-off or
landing. |
| 706. |
Analysis of operational airline
data to show the effects of airborne weather radar on the gust loads
and operating practices of twin-engine short-haul transport airplanes
( Nov 1957) by Martin R. Copp, Walter G. Walker [19 pages; 0.8
MB] |
|
Abstract: Samples of airspeed, altitude, and
acceleration measurements obtained from transport operations utilizing
airborne weather radar have been evaluated to determine the effects of
radar storm detection on the magnitudes of the gust velocities, gust
loads, and operation airspeeds. The data samples were obtained with
NACA V-G and VGH recorders installed in twin-engine short-haul
commercial transports. |
| 707. |
Transition-flight investigation
of a four-engine-transport vertical-take-off airplane model utilizing a
large flap and extensible vanes for redirecting the propeller
slipstream ( Dec 1957) by Louis P. Tosti [38 pages; 1.6
MB] |
|
Abstract: An experimental investigation has been
conducted to determine the dynamic stability and control
characteristics of a four engine-transport vertical-take-off airplane
model in the transition range from hovering to normal forward flight. |
| 708. |
Cloud-droplet ingestion in
engine inlets with inlet velocity ratios of 1.0 and 0.7 ( Jan
1957) by Rinaldo J. Brun [35 pages; 2.3 MB] |
|
Abstract: The paths of cloud droplets into two
engine inlets have been calculated for a wide range of meteorological
and flight conditions. The amount of water in droplet form ingested by
the inlets and the amount and distribution of water impinging on the
inlet walls are obtained from these droplet-trajectory calculations. In
both types of inlet, a prolate ellipsoid of revolution represents
either part or all of the forebody at the center of an annular inlet to
an engine. The configurations can also represent a fuselage of an
airplane with side ram-scoop inlets. The studies were made at an angle
of attack of 0 degree. The principal difference between the two inlets
studied is that the inlet-air velocity of one is 0.7 that of the other.
The studies of the two velocity ratios lead to some important general
concepts of water ingestion in inlets. |
| 709. |
Far noise field of air jets and
jet engines ( Jan 1957) by Edmund E. Callaghan, Willard
D. Coles [18 pages; 1.5 MB] |
|
Abstract: An experimental investigation was
conducted to study and compare the acoustic radiation of air jets and
jet engines. A number of different nozzle-exit shapes were studied with
air jets to determine the effect of exit shape on noise generation.
Circular, square, rectangular, and elliptical convergent nozzles and
convergent-divergent and plug nozzles were investigated. The spectral
distributions of the sound power for the engine and the air jet were in
good agreement for the case where the engine data were not greatly
affected by reflection or jet interference effects. Such power spectra
for a subsonic or slightly choked engine or air jet show that the peaks
of the spectra occur at a Strouhal number of 0.3. |
| 710. |
Foreign-object retention and
flow characteristics of retractable engine-inlet screens ( Jul
1957) by Fred W. Steffen, Lewis A. Rodert [31 pages; 0.9 MB] |
|
Abstract: An investigation was conducted to
determine and improve upon the foreign-object- retention capabilities
and pressure-loss characteristics of retractable engine-inlet screens.
Test were made with two commercially made retractable screens installed
in the engine-inlet sections for which they were designed. |
| 711. |
Analysis of two-spool
turboprop-engine characteristics ( Jun 1957) by Elmer H.
Davison [59 pages; 2.1 MB] |
|
Abstract: Two-spool turboprop engines with an
over-all compressor pressure ratio of 12 split 6-2, 3-4, and 2-6
between the outer and inner compressors were analytically investigated
for a range of turbine-inlet temperatures and flight conditions. |
| 712. |
Effect of ambient-temperature
variation on the matching requirements of inlet-engine combinations at
supersonic speeds ( Jan 1957) by Eugene Perchonok,
Donald P. Hearth [17 pages; 0.6 MB] |
|
Abstract: The effect of ambient temperature on
the matching requirements of inlet-engine combinations has been
analyzed for two typical turbojet engines up to a Mach number of 3.5.
The changes in ambient temperature ordinarily encountered in flight can
markedly influence the performance of matched inlet-engine combinations
for engines operated at constant mechanical speed. |
| 713. |
Results of turbojet engine
operation tests using a 50-50 mixture of JP-4 and tributyl borate as
the fuel ( January 16, 1957) by Schafer, Louis J , Jr
Stepka, Francis S [16 pages; 0.6 MB] |
|
Abstract: An experimental investigation was
conducted on a centrifugal-type turbojet engine using a 50-50 mixture
of tributyl borate and JP-4 as the fuel to determine the magnitude and
the location of the boric oxide deposits in the engine as well as the
effect of these deposits on the engine performance. Large deposits of
boric acid formed in the combustor walls and on the turbine rotor and
stator blades. The deposits had no effect on the engine thrust. |
| 714. |
A study of injection processes
for 15-percent fluorine - 85-percent oxygen and heptane in a
200-pound-thrust rocket engine ( January 15, 1957) by
Heidmann, M F [25 pages; 0.9 MB] |
|
Abstract: Characteristic exhaust velocity over a
range of mixture ratios and variations in gas velocity with distance
from the injector were measured for six injectors. Comparisons of
injector performance showed the gains obtained from oxidant
atomization, fuel atomization, and propellant mixing. The results are
compared with oxygen and heptane performance and show the effect, which
is qualitatively small, of spontaneous propellant ignition on the
relation between injection processes and engine performance. |
| 715. |
Identification of foreign
objects damaging compressor blades in turbojet engines (
January 07, 1957) by Spakowski, A E Graab, J [13 pages; 0.4 MB] |
|
Abstract: Damage to the compressor blades of
turbojet engines due to ingestion of foreign objects is a growing
problem, the solution of which has been made more difficult by the
large percentage of damaging materials that have remained unknown. A
rapid emission spectroscopic method was devised to identify the
chemical composition of these foreign objects. Results on
laboratory-prepared specimens and blades from damaged engines show that
the method can be utilized to determine the nature of the ingested
foreign objects. |
| 716. |
Comparison of effect of a
turbojet engine and three cold-flow configurations on the stability of
a full-scale supersonicle inlet ( January 24, 1957) by
Musial, Norman T [17 pages; 0.5 MB] |
|
Abstract: Increasing the volume and length of the
duct behind the inlet affected the inlet stability at Mach 2.0 and zero
angle of attack. Close approximation of the inlet stability limit of
the J34 engine-inlet configuration was obtained by a cold-pipe
configuration having a length and volume approaching that measured to
the engine turbine. Variation of these parameters had a small effect on
the minimum subcritical stable mass flow below a cowl-lip-position
parameter of 44 degrees and appeared to have a negligible effect on the
inlet pressure-recovery - mass-flow curve. Initial buzz frequency and
minimum cowl-lip-position parameter for complete buzz-free operation
varied with configuration. |
| 717. |
Arrangements of jet engine and
airframe for increased range ( July 26, 1957) by
Luidens, Roger W [87 pages; 3.4 MB] |
|
Abstract: No Abstract Available |
| 718. |
Initial performance
investigation of pentaborane fuel in free-flight ram-jet engine
( January 24, 1957) by Disher, John H Rabb, Leonard [32 pages;
0.9 MB] |
|
Abstract: No Abstract Available |
| 719. |
A study of liquid boric oxide
particle growth rates in a gas stream from a simulated jet engine
combustor ( April 30, 1957) by Setze, Paul C [42 pages;
1.3 MB] |
|
Abstract: It was experimentally determined that
the liquid boric oxide particles leaving a jet engine combustor,
burning a boron-containing fuel, will have diameters of 1.0 x 10(exp
-5) to 2.0 x 10(exp -5) centimeter. For this size range the particle
heat-transfer and drag coefficients are essentially infinite. The
results may be applied to any boron-containing fuel. Equations are
developed that enable the calculation of the particle size-time
history. A study of boric oxide deposition mechanisms is included, and
suggestions for decreading deposition rates given. |
| 720. |
Investigation of a
supersonic-inlet - turbojet-engine combination at Mach 2.0 and angles
of attack up to 6 degrees ( July 1957) by Hearth, Donald
P Musial, Norman T [26 pages; 0.7 MB] |
|
Abstract: No Abstract Available |
| 721. |
Injection principles for liquid
oxygen and heptane using nine-element injectors in an 1800-pound-thrust
rocket engine ( July 18, 1957) by Neu, Richard F [28
pages; 0.8 MB] |
|
Abstract: No Abstract Available |
| 722. |
Flight investigation of
pentaborane fuel in rocket boosted 9.75-inch-diameter ramjet engine
with convergent-divergent exhaust nozzle ( September 17, 1957)
by Disher, John H [25 pages; 1.1 MB] |
|
Abstract: No Abstract Available |
| 723. |
Flight-determined
induction-system and surge characteristics of the YF-102 airplane with
a two-spool turbojet engine ( June 28, 1957) by
Saltzman, Edwin J [33 pages; 0.9 MB] |
|
Abstract: No Abstract Available |
| 724. |
Experimental comparison of
speed : fuel-flow and speed-area controls on a turbojet engine for
small step disturbances ( March 1957) by Wenzel, L M
Hart, C E Craig, R T [57 pages; 2.4 MB] |
|
Abstract: Optimum proportional-plus-integral
control settings for speed - fuel-flow control, determined by
minimization of integral criteria, correlated well with analytically
predicted optimum settings. Engine response data are given for a range
of control settings around the optimum. An inherent nonlinearity in the
speed-area loop necessitated the use of nonlinear controls. Response
data for two such nonlinear control schemes are presented. |
| 725. |
Experimental investigation of
temperature feedback control systems applicable to turbojet-engine
control ( March 1957) by Hart, C E Wenzel, L M Craig, R
T [57 pages; 1.8 MB] |
|
Abstract: Temperature - fuel-flow and
temperature-area feedback control systems were investigated as means of
controlling tailpipe gas temperature of a turbojet engine during
transient operation in the high-speed region.
Proportional-plus-integral control was used in both systems, but in the
temperature-area control system it was necessary to add nonlinear
components to the basic proportional-plus-integral control to provide
satisfactory transient response to a desired step increase in
temperature. Time integral of temperature-error functions were used as
criteria for determining optimum transient response. A description of
engine dynamics was obtained from frequency-response data. |
| 726. |
Full-scale investigation of
several jet-engine noise-reduction nozzles ( April 1957)
by Coles, Willard D Callaghan, Edmund E [46 pages; 1.7 MB] |
|
Abstract: A number of nozzles which use the
mixing interference of adjacent jets for noise suppression were
investigated. Reductions in sound power of nearly 70 percent (5 db)
with thrust losses of 1 percent were achieved. A method of calculating
the limiting frequency affected by this type of suppression nozzle,
that is , multiple-slot nozzles, is presented. Data are shown which
indicate that further large reductions in sound power are not likely
with mixing-interference nozzles. |
| 727. |
The effect of forward-flight
speed on the propulsive characteristics of a pulse-jet engine mounted
on a helicopter rotor ( 1957) by Powell, Robert D , Jr
[24 pages; 0.8 MB] |
|
Abstract: No Abstract Available |
| 728. |
Near noise field of a
jet-engine exhaust ( 1957) by Howes, Walton L Callaghan,
Edmund E Coles, Willard D Mull, Harold R [35 pages; 2.4 MB] |
|
Abstract: Aircraft structures located in the near
noise field of a jet engine are subjected to extremely high fluctuating
pressures that may cause structural fatigue. Studies of such structures
have been limited by lack of knowledge of the loadings involved. The
acoustic near field produced by the exhaust of a stationary turbojet
engine having a high pressure ratio was measured for a single operating
condition without burning. The maximum overall sound pressure without
afterburning was found to be about 42 pounds per square foot along the
jet boundary in the region immediately downstream of the jet-nozzle
exit. With afterburning maximum sound pressure was increased by 50
percent. The sound pressures without afterburning were obtained on a
constant percentage band width basis in the frequency range from 350 to
700 cps. Cross-correlation measurements with microphones were made for
a range of jet velocities at locations along the jet and at a distance
from the jet. In general, little change in the correlation curves was
found as a function of jet velocity or frequency-band width. |
| 729. |
A hydrogen peroxide
turbojet-engine simulator for wing-tunnel powered-model investigations
( November 04, 1957) by Runckel, Jack F Swihart, John M [40
pages; 1.3 MB] |
|
Abstract: No Abstract Available |
| 730. |
Effect of fuel variables on
carbon formation in turbojet-engine combustors ( 1958)
by Edmund R. Jonash, Jerrold D. Wear, William P. Cook [18 pages; 1.9
MB] |
|
Abstract: Report presents the results of an
investigation of the effects of fuel properties and of a number of fuel
additives on combustion-chamber carbon deposition and exhaust-gas smoke
formation in a single tubular turbojet-engine combustor. Limited tests
were conducted with a number of the fuels in several full-scale
turbojet engines to verify single-combustor data. |
| 731. |
Theoretical combustion
performance of several high-energy fuels for ramjet engines (
1958) by Leonard K. Tower, Roland Breitwieser, Benson E. Gammon
[18 pages; 1.8 MB] |
|
Abstract: An analytical evaluation of the air and
fuel specific-impulse characteristics of magnesium, magnesium octene-1
slurries, aluminum, aluminum octene-1 slurries, boron, boron octene-1
slurries, carbon, hydrogen, alpha-methylnaphthalene, diborane,
pentaborane, and octene-1 is presented. While chemical equilibrium was
assumed in the combustion process, the expansion was assumed to occur
at fixed composition. |
| 732. |
Calculated and measured
stresses in simple panels subject to intense random acoustic loading
including the near noise field of a turbojet engine ( 1958)
by Leslie W. Lassiter, Robert W. Hess [10 pages; 0.9 MB] |
|
Abstract: Flat 2024-t3 aluminum panels measuring
11 inches by 13 inches were tested in the near noise fields of a 4-inch
air jet and turbojet engine. The stresses which were developed in the
panels are compared with those calculated by generalized harmonic
analysis. The calculated and measured stresses were found to be in good
agreement. In order to make the stress calculations, supplementary data
relating to the transfer characteristics, damping, and static response
of flat and curved panels under periodic loading are necessary and were
determined experimentally. In addition, an appendix containing detailed
data on the near pressure field of the turbojet engine is included. |
| 733. |
Full-scale investigation of
several jet-engine noise-reduction nozzles ( 1958) by
Willard D. Coles, Edmund E. Callaghan [24 pages; 1.9 MB] |
|
Abstract: A number of noise-suppression nozzles
were tested on full-scale engines. In general, these nozzles achieved
noise reduction by the mixing interference of adjacent jets, that is,
by using multiple-slot-nozzles. Several of the nozzles achieved
reductions in sound power of approximately 5 decibels (nearly 70
percent) with small thrust losses (approx. 1 percent). The maximum
sound-pressure level was reduced by as much as 18 decibels in
particular frequency bands. Some of the nozzles showed considerable
spatial asymmetry; that is, the sound field was not rotationally
symmetrical. A method of calculating the limiting frequency effected by
such nozzles is presented. Furthermore data are shown that appear to
indicate that further reductions in sound power will not be easily
achieved from nozzles using mixing interference as a means of noise
suppression |
| 734. |
Experimental investigation of
turbojet-engine multiple-loop controls for non-afterburning and
afterburning modes of engine operation ( Jan 1958) by
Donald B. Kirsch, Leon M. Wenzel, Clint E. Hart [62 pages; 3.8 MB] |
|
Abstract: An experimental investigation of
turbojet-engine performance with several configurations of interacting
multiple-loop controls was conducted to determine the mode of control
required for obtaining optimum rotor speed and turbine-discharge
temperature transient response characteristics during (1) thrust
increase and (2) afterburner ignition by manipulation of engine fuel
flow and exhaust-nozzle area. The engine operating point chosen for
examining the control systems was near the rated-thrust level.
Effective increases in engine thrust were obtained by rapidly opening
the nozzle area while simultaneously increasing engine fuel flow.
Following the afterburner ignition, opening the nozzle area rapidly
while holding an esentiallly constant engine fuel flow practically
eliminated compressor surge tendencies. Good engine transient
performance characteristics were obtained with a control system in
which engine speed was controlled by manipulation of exhaust-nozzle
area and turbine-discharge temperature was controlled by manipulation
of engine fuel flow. An alternate control system, which gives
acceptable, although more oscillatory, transient responses, was the
double-loop configuration in which speed was controlled by manipulation
of engine fuel flow, turbine-discharge temperature was controlled by
manipulation of exhaust-nozzle area, and a noninteraction gain term was
incorporated from the speed to the temperature control loops. |
| 735. |
Propellant vaporization as a
criterion for rocket engine design : relation between percentage of
propellant vaporized and engine performance ( Mar 1958)
by Marcus F. Heidmann, Richard J. Priem [20 pages; 0.7 MB] |
|
Abstract: An analysis is presented on the
quantitative effect of incomplete propellant vaporization on
rocket-engine performance. A relation between characteristic exhaust
velocity c* and the percentages of oxidant and fuel vaporized and
burned is given. The analysis shows that c* efficiencies of 70 to 90
percent can be realized when only half the fuel is vaporized, whereas
c* efficiencies of about 60 percent can be realized when half the
oxidant is vaporized. The specific relations between c* and propellant
vaporized are presented graphically for the hydrogen-fluorine,
hydrogen-oxygen, ammonia-fluorine, and JP-4 - oxygen propellant
combinations. The analysis is applied to experimental data for these
propellant combinations. |
| 736. |
An analysis of ramjet engines
using supersonic combustion ( Sep 1958) by Richard J.
Weber, John S. Mackay [50 pages; 1.9 MB] |
|
Abstract: Based on the assumption that shock-free
internal burning is possible in a supersonic airstream, calculations
are made for the performance of ramjets using supersonic combustion
velocities. Diffusion of the air from the flight speed to a lower
supersonic velocity is generally found to be desirable before the air
enters the combustor. With a constant-area combustor, both maximum
thrust and overall engine efficiency are achieved when sufficient heat
is added to choke the flow at the combustor exit. |
| 737. |
Turbojet engine noise reduction
with mixing nozzle-ejector combinations ( Aug 1958) by
Willard D. Coles, John A. Mihaloew, Edmund E. Callaghan [34 pages; 1.2
MB] |
|
Abstract: Several noise suppressors consisting of
combinations of mixing nozzles and ejectors were tested on two
full-scale turbojet engines. Maximum sound pressure level reductions of
12\ decibels and sound power level reductions of 8 decibels were
obtained. The ejectors provided 3 to 5 decibels of the sound power
reduction. The effects of ejector dimensions on noise suppression and
engine performance were investigated. |
| 738. |
Comparison of injectors with a
200-pound-thrust ammonia-oxygen engine ( September 04, 1958)
by Priem, Richard J Clark, Bruce J [10 pages; 0.2 MB] |
|
Abstract: No Abstract Available |
| 739. |
Experimental results of an
investigation of two methods of inflight thrust measurement applicable
to afterburning turbojet engines with ejectors ( May 02, 1958)
by Bloomer, Harry E [37 pages; 1.4 MB] |
|
Abstract: No Abstract Available |
| 740. |
Aerodynamic and
inlet-flow-field characteristics at a free-stream Mach number of 3.0
for airplanes with circular fuselage cross sections and for two engine
locations ( March 18, 1958) by Dryer, Murray Luidens,
Roger W [33 pages; 0.9 MB] |
|
Abstract: No Abstract Available |
| 741. |
Performance of basic XJ79-GE-1
turbojet engine and its components ( May 08, 1958) by
Campbell, Carl E [57 pages; 2.1 MB] |
|
Abstract: No Abstract Available |
| 742. |
A study of the combustion rates
of hydrocarbon fuels with red fuming nitric acid in a small rocket
engine ( August 06, 1958) by Baker, Louis, Jr [43 pages;
1.3 MB] |
|
Abstract: No Abstract Available |
| 743. |
Combustor performance with
various hydrogen-oxygen injection methods in a 200-pound-thrust rocket
engine ( September 30, 1958) by Heidmann, M F Baker,
Louis, Jr [46 pages; 1.1 MB] |
|
Abstract: No Abstract Available |
| 744. |
A theoretical analysis of the
effect of engine angular momentum on longitudinal and directional
stability in steady rolling maneuvers ( April 1958) by
Gates, Ordway B , Jr Woodling, C H [21 pages; 0.4 MB] |
|
Abstract: No Abstract Available |
| 745. |
Acoustic, thrust, and drag
characteristics of several full-scale noise suppressors for turbojet
engines ( April 1958) by Ciepluch, Carl C North, Warren
J Coles, Willard D Antl, Robert J [49 pages; 1.7 MB] |
|
Abstract: No Abstract Available |
| 746. |
Effect of prior air force over
temperature operation on life of J47 buckets evaluated in a sea-level
cyclic engine test ( April 1958) by Signorelli, Robert A
Johnston, James R Garrett, Floyd B [42 pages; 1.4 MB] |
|
Abstract: No Abstract Available |
| 747. |
Effect of target-type thrust
reverser on transonic aerodynamic characteristics of a single-engine
fighter model ( January 13, 1958) by Swihert, John M [44
pages; 1.1 MB] |
|
Abstract: A brief investigation of a target-type
thrust reverser on a single-engine fighter model has been conducted in
the Langley 16-foot transonic tunnel at Mach numbers from 0.20 to
1.05.At Mach numbers of 0.80, 0.92, and 1.05, a hydrogen peroxide
turbojet-engine simulator was operated with the thrust reverser
extended. The angle of attack was varied from 0 degrees to 5 degrees at
these Mach numbers. The Reynolds number of the free stream, based on
the mean aerodynamic chord, was about 5 x 10(6). It was estimated that
reversed jet operations separated the model boundary-layer flow over
the upper surface of the horizontal tail and upper part of the
afterbody. This resulted in a positive pitch increment due to reversed
jet operation. Jet-on operation also tended to stabilize the severe
lateral oscillations which occurred with the reverser extended and the
jet off. It appeared that these jet-off oscillations were the result of
an alternating separation and reattachment of the flow on the rearmost
portions of the fuselage afterbody. |
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