National Advisory Committee for Aeronautics (NACA) - 12 Matching Results

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Altitude Cooling Investigation of the R-2800-21 Engine in the P-47G Airplane 4 - Engine Cooling-Air Pressure Distribution
"A study of the data obtained in a flight investigation of an R-2800-21 engine in a P-47G airplane was made to determine the effect of the flight variables on the engine cooling-air pressure distribution. The investigation consisted of level flights at altitudes from 5000 to 35,000 feet for the normal range of engine and airplane operation. The data showed that the average engine front pressures ranged from 0.73 to 0.82 of the impact pressure (velocity head). The average engine rear pressures ranged from 0.50 to 0.55 of the impact pressure for closed cowl flaps and from 0.10 to 0.20 for full-open cowl flaps" (p. 1).
A Device for Measuring Sonic Velocity and Compressor Mach Number
"A device has been developed which measures the velocity of sound in fluids at stagnation and is especially adaptable to turbine and compressor testing for which the constituency of the working fluid may be in doubt. By utilizing the shaft frequency of a rotary compressor, the instrument can also be used to provide a direct measurement of the compressor Mach number (ratio of blade-tip velocity to inlet velocity of sound at stagnation). A Helmholtz resonator is employed in the measurement of the sound velocity" (p. 1).
Effect of Engine Skew on Directional and Lateral Control Characteristics of Single-Engine Airplanes
Report discussing an investigation on the effect of engine skew on the directional and lateral control characteristics of a single-engine airplane with a single-rotating propeller. The estimated and test results showed an advantage to skewing the propeller, as it assists with overcoming inadequate rudder control in power-on flight and aileron control, especially with flaps deflected.
Effect of Modifications to Induction System on Altitude Performance of V-1710-93 Engine 3: Use of Parabolic Rotating Guide Vanes and NACA Designed Auxiliary-Stage Inlet Elbow and Interstage Duct
"Bench runs of a modified V-1710-93 engine equipped with a two-stage supercharger, interstage carburetor, aftercooler assembly, and backfire screens have been made at a simulated altitude of 29,000 feet to determine the effect of several induction-system modifications on the engine and supercharger performance. The standard guide vanes on the auxiliary- and engine-stage superchargers were replaced by rotating guide vanes with a parabolic blade profile. The auxiliary-stage inlet elbow and interstage duct were replaced with new units of NACA design. These modifications were made one at a time and data were obtained after each change to determine the effect of each modification" (p. 1).
Flight Tests of a Curtiss No. 838-1C2-18 Three-Blade Propeller Having Trailing-Edge Extensions
"Flight tests to determine propeller performance have been made of a Curtiss No. 838-102-18 three-blade propeller having trailing-edge extensions on a Republic P-47D-28 airplane in climb and high speed. These tests are a part of a general propeller flight-test program at the Langley Laboratory of the National Advisory Committee for Aeronautics. Results of climb tests indicate that when power is changed from approximately 1475 horsepower at 2550 rpm (roughly normal power) to 2400 horsepower at 2700 rpm (approximately military power) there is a loss in propeller efficiency of 3 percent at an altitude of 7000 feet, and 4 percent at 21,000 feet" (p. 1).
General Treatment of Compressible Flow in Ejectors and Example of Its Application to Problem of Effect of Ejector Addition on Thrust of Jet-Propulsion Units
Memorandum presenting a general treatment of compressible flow in ejectors with friction in the mixing tube included. A secondary object is to show the application of the flow theory to the calculation of the effect of ejector addition on thrust of jet-propelled airplanes and missiles. Results regarding the outline of methods of applying the general theory to some other problems and future explorations of ejector problems are provided.
[Memorandums on the Subject of D-558 Airplane]
"An investigation of the air-stream fluctuations at the tail of the D-558-1 airplane has been made at high speed for the purpose of determining the vertical region in which the horizontal tail may be placed without becoming subject to tail buffeting. The investigation was made for a range of Mach numbers from 0.775 to 0.907, and a range of vertical positions at the tall to include two proposed horizontal-tail positions. The tests were made at two angles of attack, 0,2 deg. and 4.2 deg., representative, of the angles of attack for high-speed level flight and a pull-out condition" (p. 1).
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.
Preliminary Results of a Flight Investigation to Determine the Effect of Negative Flap Deflection on High-Speed Longitudinal-Control Characteristics
Report presenting flight testing on two propeller-driven airplanes with wings of NACA 66-series and NACA 230-series airfoil sections to determine the effect of deflecting the landing flaps upward on the high-speed longitudinal-control characteristics.
A suggested method of analyzing for transonic flutter of control surfaces based on available experimental evidence
Report presenting the results of a study of the movement of shocks on a three-dimensional wing with and without aileron flutter occurring. The studies include a number of changes and variations to the wing and control. Results for the standard wing and aileron, spoilers at 50 percent chord, upper and lower surface, faired bumps at the 50-percent-chord and 70-percent-chord positions, variations of thickness ratio along the span, vent holes between upper and lower surface, aileron-contour change, aileron mass overbalance, dampers, wing flutter, buffeting forces on fixed controls, and static characteristics are provided.
A Theoretical Investigation of Hydrodynamic Impact Loads on Scalloped-Bottom Seaplanes and Comparisons With Experiment
"An analytical method is presented for calculating the hydrodynamic impact loads and motions experienced by seaplane floats and hulls with scalloped (fluted) bottoms. The analysis treats vertical impact at zero trim in addition to the more general problem of the step impact of a seaplane at positive trim where the flight path is oblique to the keel and to the water surface. Also considered are the transformations required to represent impacts into waves" (p. 109).
Wind-Tunnel Tests of a 1/4-Scale Model of the Naval Aircraft Factory Float-Wing Convoy Interceptor, TED No. NACA 2314
A 1/4 - scale model of the Naval Aircraft Factory float-wing convoy interceptor was tested in the Langley 7-by 10-foot tunnel to determine the longitudinal and lateral stability characteristics. The model was tested in the presence of a ground board to determine the effect of simulating the ground on the longitudinal characteristics.