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- Theoretical and Experimental Analysis of Low-Drag Supersonic Inlets Having a Circular Cross Section and a Central Body at Mach Numbers of 3.30, 2.75, and 2.45
- Memorandum presenting a discussion of inlets with a circular cross section and a central body designed for high Mach numbers. The optimum proportion between external and internal supersonic compression is discussed in relation to the external drag and the maximum pressure recovery. Results and analysis regarding the maximum pressure recovery as a function of the cowling position parameter, the effect of the cone angle parameter on the maximum pressure recovery obtained, the highest pressure recovery obtained as a function of the central-body-diameter parameter, the maximum pressure recovery as a function of Mach number, and optical observations of the flow phenomena about the inlets are provided.
- Two-dimensional aerodynamic characteristics of 34 miscellaneous airfoil sections
- The aerodynamic characteristics of 34 miscellaneous airfoils tested in the Langley two-dimensional low-turbulence tunnels are presented. The data include lift, drag, and in some cases, pitching-moment characteristics, for Reynolds numbers between 3.0 x 10 (exp 6) and 9.0 x 10 (exp 6).
- The interaction of boundary layer and compression shock and its effect upon airfoil pressure distributions
- Report presenting an investigation of the mechanism of interaction of compression shock with boundary layer. Shockless pressure distributions at supercritical Mach numbers were found to be accounted for by a marked thickening of the boundary layer for some distance ahead of a shock wave.
- Comparative Drag Measurements at Transonic Speeds of an NACA 65-006 Airfoil and a Symmetrical Circular-Arc Airfoil
- Report presenting measurements made at transonic speeds by the freely-falling-body method to compare the drag of a rectangular plan-form airfoil of aspect ratio 7.6 with an NACA 65-006 airfoil section. Results regarding the velocity measurements, base-pressure measurements, and airfoil drag measurements are provided.
- Comparison of National Bureau of Standards ceramic coatings L-7C and A-417 on turbine blades in a turbojet engine
- Report presenting an investigation to determine which of two ceramic coatings, L-7C and A-417, developed by the National Bureau of Standards is more suitable as a protective coating for turbine blades in a turbojet engine. Four cast Vitallium turbine blades, two coated with each of the ceramics, were installed in a turbine wheel of a turbojet engine and subjected to accelerated cyclic life tests.
- Free-Flight Investigation of Control Effectiveness of Full-Span 0.2-Chord Plain Ailerons at High Subsonic, Transonic, and Supersonic Speeds to Determine Some Effects of Section Thickness and Wing Sweepback
- Report discusses the development and testing of a rocket-propelled test vehicle to investigate aerodynamic control effectiveness at high subsonic, transonic, and supersonic speeds. Modifications to the section thickness and wing sweepback to improve performance are also described. A description of the vehicle, instrumentation, accuracy, and evaluation of testing results is included.
- Force and Longitudinal Control Characteristics of a 1/16-Scale Model of the Bell XS-1 Transonic Research Airplane at High Mach Numbers
- Report presenting part of the results obtained to determine the effects of compressibility at high Mach numbers on a model of the Bell XS-1 transonic research airplane. General trends that can be qualitatively analyzed for level-flight Mach numbers up to 0.93 are given. Results regarding force characteristics and a comparison of results with wing-flow investigation are also provided.
- Wind-Tunnel Investigation of Bomb-Bay Configurations Intended to Minimize the Tumbling of Light-Weight Bombs
- Report presenting an investigation in the 300 mph 7- by 10-foot tunnel to determine what modifications could be made to conventional bomb bays to reduce the tumbling difficulties experienced with light-weight bombs. The investigation indicated that there is a definite region of reversed flow inside the bomb bay which must be weakened or destroyed if good drops are to be obtained.
- Free-Flight Investigation at Transonic and Supersonic Speeds of the Rolling Effectiveness of Several Aileron Configurations on a Tapered Wing Having 42.7 Degrees Sweepback
- Report presenting an investigation of several aileron modifications in conjunction with a tapered, sweptback wing with circular-arc airfoil sections of relatively large thickness ratio. This testing permits the evaluation of the wing-aileron rolling effectiveness over a range of Mach numbers. Results regarding true-contour ailerons, extended-chord ailerons, and blunt trailing-edge ailerons are provided.
- Fuel Tests on an I-16 Jet-Propulsion Engine at Static Sea-Level Conditions
- Memorandum presenting an investigation of the effect of fuel composition and boiling point on the performance of the type of I-16 jet-propulsion engine. Testing occurred with 14 fuels embodying different types of hydrocarbon and with a range of boiling points. The results indicated that fuel composition and boiling range have a negligible effect on engine thrust, rotor speed, and gas temperatures for the principal types of hydrocarbon fuel when used for short periods of time.
- Aerodynamic Characteristics of a 42 Degree Swept-Back Wing With Aspect Ratio 4 and NACA 64(Sub 1)-112 Airfoil Sections at Reynolds Numbers From 1,700,000 to 9,500,000
- Report discussing testing on a 42 degree swept-back wing to determine its low-speed aerodynamic characteristics in pitch and yaw at high Reynolds numbers. The main effect of increasing the Reynolds number was delayed wing stalling to higher angles of attack. Roughness on the wing leading edge also had a large adverse effect on lift, drag, and pitching-moment characteristics at higher Reynolds numbers.
- Performance Investigation of a Jumo 004 Combustor
- Report presenting an investigation of a German Jumo 004 combustor under conditions simulating zero-ram operation of a 24C jet-propulsion engine over ranges of altitude and engine speed to obtain the altitude operating limits and characteristics. Combustion efficiency, outlet-temperature distribution, and total-pressure drop were determined. The performance of the combustor with 62-octane and JP-1 fuels were also compared.
- Altitude cooling investigation of the R-2800-21 engine in the P-47G airplane 2: investigation of the engine & airplane variables affecting the cylinder temperature distribution
- "The data obtained from cooling tests of an R-2800-21 engine installed in a P-47G airplane were studied to determine which engine and airplane operation variables were mainly responsible for the extremely uneven temperature distribution among the 18 engine cylinders obtained at the medium and high engine-power conditions. The tests consisted of flights at altitudes from 5000 to 35,000 feet for the normal range of engine and airplane operation. The results of the study showed that a flow condition in the induction system associated with the wide-open throttle position, which affected either the fuel air or charge distribution, was primarily responsible for the uneven temperature distribution" (p. 1).
- Investigation of Internal Regenerative Fuel-Heating System for 20-Inch Ram Jet
- Memorandum presenting an investigation conducted to evaluate the effectiveness of a simple internal regenerative fuel preheater for a 20-inch-diameter ram jet. Data obtained at subsonic sea-level conditions indicated that fuel could be successfully preheated in this manner.
- Results obtained from second flight of X-4 airplane (A.F. no. 46-676)
- Report presenting testing in the X-4 airplane to obtain stability and control data. The flight was made with the center of gravity at 19.7 percent of the mean aerodynamic chord and with the rudder-boost system removed. The results showed that the longitudinal stability was positive in the clean condition and in the gear-down flaps-up condition.
- Vibration of turbine blades in a turbojet engine during operation
- Report presenting an experimental investigation to determine the vibration phenomena that occur in turbine blades of a typical jet-propulsion engine during service operation; high-temperature strain gages were used to measure the turbine-blade vibrations. Results regarding modes of vibration, centrifugal stresses, and vibration of turbine blades during operation are provided.
- Free-flight performance of 16-inch-diameter supersonic ram-jet units 1: four units designed for combustion-chamber-inlet Mach number of 0.12 at free-stream Mach number of 1.6 (units A-2, A-3, A-4, and A-5)
- Report presenting free-flight investigations conducted on four 16-inch-diameter ramjet units to determine the performance at high subsonic and supersonic velocities. Data for evaluating the performance were obtained from radio-telemetering and radar-tracking equipment. Results regarding combustion performance, diffuser total-pressure recovery, thrust coefficient, and external drag coefficient are provided.
- Experimental investigation of hot-gas bleedback for ice protection of turbojet engines 2: nacelle with long straight air inlet
- Report presenting aerodynamic and icing investigations conducted in the icing research tunnel on a model of a turbojet-engine nacelle with a long straight air inlet in order to provide basic design criteria for hot-gas blowback systems. The most uniform temperature distribution was obtained with a bleedback of 4.4 percent at a gas temperature of 1000 degrees Fahrenheit and resulted in an average dry-air-temperature rise of 46 degrees Fahrenheit.
- Experimental Investigation of the Effects of Sweepback on the Flutter of a Uniform Cantilever Wing With a Variably Located Concentrated Mass
- Report presenting data from 95 subsonic flutter tests conducted in the flutter research tunnel on untapered cantilever wings with sweepback angles of 0, 45, and 60 degrees and carrying a single concentrated weight. The primary purpose of the investigation was to present experimental information to be used to evaluate analytical procedures for determining the flutter speed of weighted sweptback wings. The dynamic pressure, flutter velocity, Mach number, natural and flutter frequencies, and phase-angle relationships of the stresses for the natural and flutter frequencies are presented.
- Aerodynamic Study of a Wing-Fuselage Combination Employing a Wing Swept Back 63 Degrees: Characteristics Throughout the Subsonic Speed Range With the Wing Cambered and Twisted for a Uniform Load at a Lift Coefficient of 0.25
- Report presenting wind-tunnel testing to determine the independent effects of Mach and Reynolds numbers on the aerodynamic characteristics of a wing-fuselage combination with a wing with the leading edge swept back 63 degrees and with camber and twist. Results regarding the fuselage alone and the effects of camber and twist are also provided.
- Effect of a pilot's canopy on the drag of an NACA RM-2 drag research model in flight at transonic and supersonic speeds
- Report presenting data from two experiments. One used the NACA RM-2 drag research model equipped with a pilot's canopy to determine the effect on aerodynamics. The other was conducted with the same configuration and returned similar results.
- Pressure-Distribution Data for the NACA 64(Sub 1)-012 and 64(Sub 1)A012 Airfoils at High Subsonic Mach Numbers
- "Pressure-distribution data of the NACA 64(sub 1)-012 and 64(sub 1)A012 airfoils have been analyzed to determine the effects of increasing the trailing-edge angle from 9 to 14 degrees. The primary effect of increasing the trailing-edge angle was to decrease the loading over the rear portion of the airfoil under lifting conditions. The differences in trailing-edge load increased with Mach number and lift coefficient" (p. 1).
- Effects of several leading-edge modifications on the stalling characteristics of a 45 degree swept-forward wing
- Report presenting an investigation to determine the effects of several leading-edge modifications on the maximum lift and pitching-moment characteristics on a large-scale 45 degree swept-forward wing. A full-span leading-edge flap deflected 30 degrees down tended to give the largest gain of maximum lift. Results regarding the plain leading-edge flaps and cambered nose are explored.
- Aerodynamic study of a wing-fuselage combination employing a wing swept back 63 degrees: Effects of split flaps, elevons, and leading-edge devices at low speed
- Report presenting an investigation to evaluate the effects of split flaps, elevons, sharp leading edges, drooped-nose flaps, and extended-nose flaps on the lift, drag, and pitching-moment characteristics at low speed of a wing-fuselage combination with a wing with the leading edge swept back 63 degrees and an aspect ratio of 3.5. Results regarding the plain wing and wing-fuselage combinations, Reynolds number, split flaps, elevons, leading-edge devices, and highest lift coefficient attained before longitudinal instability are provided.
- A comparison of the experimental subsonic pressure distributions about several bodies of revolution with pressure distributions computed by means of the linearized theory
- Report presenting an analysis of the effects of compressibility on the pressure coefficients of several bodies of revolution by comparing experimentally determined pressure coefficients with corresponding pressure coefficients calculated by the use of linearized equations of compressible flow. The results indicated that the theoretical methods predict the subsonic pressure-coefficient changes over the central portion of the body but do not predict the pressure-coefficient changes near the nose.
- Analysis of the Effects of Various Mass, Aerodynamic, and Dimensional Parameters on the Dynamic Lateral Stability of the Douglas D-558-2 Airplane
- Report presenting an investigation of the effects of various mass, aerodynamic, and dimensional parameters on the dynamic lateral stability of the Douglas D-558-2 airplane. Results regarding an airplane with the flaps and gear retracted, airplane at sea level with flaps deflected 50 degrees and landing gear lowered, and effect of assumed modifications to airplane are provided.
- High-subsonic damping-in-roll characteristics of a wing with the quarter-chord line swept back 35 degrees and with aspect ratio 3 and taper ratio 0.6
- Report presenting an investigation of the damping-in-roll characteristics of a 35 degree sweptback wing, with and without vertical fins, through a range of Mach numbers in the high speed 7- by 10-foot tunnel utilizing a free-to-roll technique. The damping-in-roll coefficient increased in magnitude with Mach number in the manner indicated by theory and generally was found to increase in magnitude with angle of attack over the range tested.
- Tests of Lifting Surfaces on Conical and Cylindrical Portions of a Body at Subsonic Mach Numbers and at a Mach Number of 1.2
- Report presenting testing of low-aspect-ratio triangular-plan-form lifting surfaces located on conical and cylindrical portions of a body have been determined at Mach number 1.2 and several subsonic speeds to determine if the aerodynamic characteristics of these surfaces at supersonic speeds could be improved by locating them in the subsonic conical-flow field. Results regarding lift and drag coefficients and lift-curve slopes are provided.
- Study of compressor systems for a gas-generator engine
- Report presenting various methods of providing compressor-capacity and pressure-ratio control in the gas-generator type of compound engine over a range of altitudes. The analytical results indicated that the best method of control is that in which the first stage of compression is carried out in a variable-speed supercharger driven by a hydraulic slip coupling. Results regarding the constant-pressure-ratio compressor, constant-volume compressor, comparison of piston-type and rotary compressors, effect of variable-area turbine nozzle, and effect of designing for high altitudes are provided.
- Properties of certain intermetallics as related to elevated-temperature applications 1: molybdenum disilicide
- Report presenting a method for the preparation and purification of the intermetallic molybdenum desilicide was developed and its properties were determined. Chemical properties were found to be highly inert, unattacked by boiling hydrochloric acid, sulfuric acid, or aqueous sodium hydroxide, slightly attacked by nitric acid, and dissolved by molten sodium hydroxide. Other mechanical properties of the material were also provided.
- Effect of an Increase in Hull Length-Beam Ratio From 15 to 20 on the Hydrodynamic Characteristics of Flying Boats
- Report presenting an investigation of the effect of hull length-beam ratio on the hydrodynamic characteristics of flying boats that extend to a length-beam ratio of 20. The results are compared with flying boats having a length-beam ratio of 15. Results regarding longitudinal stability, spray characteristics, take-off performance, taxiing and take-off behavior in waves, landing behavior in waves, and a summary chart are provided.
- Experimental investigation at supersonic speeds of twin-scoop duct inlets of equal area 4: some effects of internal duct shape upon an inlet enclosing 37.2 percent of the forebody circumference
- Report presenting tests to determine the recovery of total pressure attainable at a range of Mach numbers, which were performed with models with twin-scoop inlets situated on the sides of a long forebody. Results regarding ducts without slots and ducts with slots are provided.
- Preliminary analysis of axial-flow compressors having supersonic velocity at the entrance of the stator
- Report presenting a supersonic compressor design with supersonic velocity at the entrance of the stator on the assumption of two-dimensional flow. The rotor and stator losses assumed in the analysis are based on the results of preliminary supersonic cascade tests. The starting conditions and stability of the flow in rotor and stator are discussed, and the desirability of the variable-geometry stators and adjustable guide vanes is indicated.
- Analytical and Experimental Investigation of 90 Degrees Supersonic Turning Passages Suitable for Supersonic Compressors or Turbines
- "Four 90 degree two-dimensional turning passages designed by the method of characteristics were tested at an inlet Mach number of 1.71. The measured losses varied from 5 to 15 percent of the inlet stagnation pressure. The smallest loss was obtained for a passage in which separation on the convex surface was minimized through the introduction of a favorable pressure gradient" (p. 1).
- Reynolds number effect on axial-flow compressor performance
- Investigation conducted in the altitude wind tunnel to study the effect of Reynolds number on the performance of an axial-flow compressor. The compressor was operated as a part of a turbojet engine over a range of pressure altitudes and compressor-inlet Reynolds numbers. Results regarding compressor efficiency, air flow, and a comparison with axial-flow compressors of different design are provided.
- Full-Scale Investigation of a Wing With the Leading Edge Swept Back 47.5 Degrees and Having Circular-Arc and Finite-Trailing-Edge-Thickness Ailerons
- Report presenting an investigation to determine the aerodynamic characteristics of a wing with a leading sweptback edge at 47.5 degrees and a 20-percent-chord, 50-percent-span outboard aileron. The wing had symmetrical circular-arc airfoil sections and was tested with a circular-arc contour aileron and a flat-sided contour aileron with finite trailing-edge thickness. The longitudinal aerodynamic characteristics and aileron effectiveness are provided for both types of ailerons.
- Method of Determining Centrifugal-Flow-Compressor Performance With Water Injection
- Memorandum presenting a method for computing the isentropic and actual enthalpy change between the inlet and outlet of a centrifugal-flow compressor when water injection is used. The method of calculation is based on fluid property values given in steam and air tables.
- Tests of a model horizontal tail of aspect ratio 4.5 in the Ames 12-foot pressure wind tunnel I : quarter-chord line swept back 35 degrees
- Report presenting wind-tunnel tests that have been conducted to evaluate the independent effects of Reynolds and Mach numbers on the aerodynamic characteristics of a horizontal tail of aspect ratio 4.5 with a plain sealed elevator with a tab. Lift, drag, pitching moment, elevator hinge moment, tab hinge moment, streamwise distribution of static pressure at the midsemispan, and pressure difference across the elevator-nose seal were measured.
- Experimental pressure distribution on a asymmetrical nonconical body at Mach number 1.90
- Report presenting an investigation of the pressure distribution on an asymmetrical nonconical body at a Mach number of 1.90 over a wide range of angles of attack and yaw. Pressure distributions occurred at anticipated trends. Results regarding the pressure coefficients, Schileren photographs, boundary layers, and pressure distributions are provided.
- Cyclic engine operation of cast vitallium turbine blades at an exhaust-cone gas temperature of 1440 plus or minus 20 F
- Report presenting an investigation conducted to determine the effects of increased gas temperatures on the performance of cast Vitallium blades in a turbojet engine. Results regarding the experimental investigation and metallurgical investigation are provided.
- Hydrodynamic Characteristics of Aerodynamically Refined Planing-Tail Hulls
- Report presenting an investigation to determine the hydrodynamic characteristics of two aerodynamically refined planing-tail hulls. One hull had an afterbody shaped like a tapered boom and the other had two afterbodies with tapered booms fairing out of engine nacelles. Results regarding take-off stability and trim, landing stability, spray, resistance, directional stability, and static transverse stability are presented.
- Analysis of the dynamic lateral stability characteristics of the Bell X-2 airplane as affected by variations in mass, aerodynamic, and dimensional parameters
- Report presenting an analysis of the dynamic-lateral-stability characteristics of the Bell X-2 airplane as affected by variations in mass, aerodynamic, and dimensional parameters by means of calculations of the period and rate of damping of the lateral oscillation. Results regarding the airplane with flaps and gear retracted, airplane with flaps and gear lowered, and effects of assumed modifications to the airplane are provided.
- Investigation at large scale of the pressure distribution and flow phenomena over a wing with the leading edge swept back 47.5 degrees having circular-arc airfoil sections and equipped with drooped-nose and plain flaps
- Report presenting an investigation of the pressure distribution over a wing with the leading-edge swept back 47.5 degrees and with symmetrical circular-arc airfoil sections in the full-scale tunnel at a designated Mach and Reynolds number. The investigation included measurements of the surface static pressures along the chord for six spanwise stations, for a large angle-of-attack range, and for several angles of yaw.
- Effects of systematic changes of trailing-edge angle and leading-edge radius on the variation with Mach number of the aerodynamic characteristics of a 10-percent-chord-thick NACA airfoil section
- Report presenting the results of a wind-tunnel investigation of the effects of variation of trailing-edge angle and leading-edge radius on the aerodynamic characteristics of a 10-percent-chord-thick airfoil section at a range of Mach numbers.
- Preliminary Measurements of the Dynamic Lateral Stability Characteristics of the Douglas D-588-II (BuAero No. 37974) Airplane
- "This paper presents some data on the dynamic lateral stability characteristics of the Douglas D-558-II (BuAero No. 37974) airplane. For the airplane in the clean condition, the lateral oscillations are lightly damped. In the landing condition, the airplane performs a constant-amplitude lateral oscillation" (p. 1).
- Comparison of the Aerodynamic Characteristics of the NACA 0010 and 0010-64 Airfoil Sections at High Subsonic Mach Numbers
- Report presenting an investigation to determine the lift, drag, and pitching-moment characteristics of the NACA 0010 and 0010-64 airfoil sections at Mach numbers up to 0.91 and for a range of Reynolds numbers.
- Effects of wing-tip turrets on the aerodynamic characteristics of a typical bomber-wing model
- Report presenting wind-tunnel tests up to a Mach number of 0.85 to determine the effects of wing-tip gun turrets on the aerodynamic characteristics of a typical bomber-wing model. Lift, drag, and pitching-moment data are presented for the wing alone; for the wing with the turrets in the clean condition; and for the wing and the turrets with guns and sighting equipment. The turrets had negligible effect on the lift and pitching-moment characteristics of the wing.
- Analysis of measured pressures on airfoils at Mach numbers near 1
- Report presenting measured pressure over airfoils at Mach number 1, with subsonic velocities at the nose and supersonic velocities throughout the rear portion, are analyzed by comparison with calculations for similar cases. Results regarding the theoretical basis of approximation, comparison of Prandtl-Meyer flow with measurements, comparison of linear-velocity extrapolation with measurements, and effect of boundary layer upon airfoil pressures are provided.
- Measurements of Aileron Effectiveness of the Bell X-1 Airplane at Mach Numbers Between 0.9 and 1.06
- "Abrupt rudder-fixed aileron rolls have been made with the Bell X-1 airplane in powered flight at Mach numbers between 0.90 and 1.06 at about 40,000 feet pressure altitude. These aileron rolls indicate that the aileron effectiveness for large deflections at Mach number 0.94 is only one-fourth the value at Mach number 0.82, and the effectiveness at Mach number 1.06 is slightly greater than at Mach number 0.94" (p. 1).
- The Effect of Rear Chine Strips on the Take-Off Characteristics of a High-Speed Airplane Fitted With NACA Hydro-Skis
- "Results are presented from tank take-off tests of a dynamic model of a hypothetical high-speed airplane fitted with NACA hydro-skis and having the transverse curvature of the lower rear portion of the fuselage broken by small longitudinal chine strips. For the configuration tested, both trim and resistance were considerably reduced by the addition of the strips from the speed at which the ski emerged to the speed at which the rear of the fuselage came clear of the water. The results indicate that fuselage shape has a large effect on the take-off characteristics for a hydro-ski configuration in which the rear of the fuselage acts as a planing surface" (p. 1).