National Advisory Committee for Aeronautics (NACA) - 42 Matching Results

Search Results

Preignition characteristics of several fuels under simulated engine conditions

Description: "The preignition characteristics of a number of fuels have been studied under conditions similar to those encountered in an engine. These conditions were simulated by suddenly compressing a fuel-air mixture in contact with an electrically heated hot spot in the cylinder head of the NACA combustion apparatus. Schlieren photographs and indicator cards were taken of the burning, and the hot-spot temperatures necessary to cause ignition under various conditions were determined" (p. 121).
Date: September 16, 1940
Creator: Spencer, R. C.
Partner: UNT Libraries Government Documents Department

Nonstationary flow about a wing-aileron-tab combination including aerodynamic balance

Description: This paper presents a continuation of the work published in Technical Report no. 496. The results of that paper have been extended to include the effect of aerodynamic balance and the effect of a tab added to the aileron. The aerodynamic coefficients are presented in a form convenient for application to the flutter problem.
Date: December 16, 1941
Creator: Theodorsen, Theodore & Garrick, I. E.
Partner: UNT Libraries Government Documents Department

A Method for Determining the Camber and Twist of a Surface to Support a Given Distribution of Lift, With Applications to the Load Over a Sweptback Wing

Description: "A graphical method is described for finding the shape (camber and twist) of an airfoil having an arbitrary distribution of lift. The method consists in replacing the lifting surface and its wake with an equivalent arrangement of vortices and in finding the associated vertical velocities. By division of the vortex pattern into circular strips concentric about the downwash point instead of into the usual rectangular strips, the lifting surface is reduced for each downwash point to an equivalent loaded line for which the induced velocity is readily computed" (p. 543).
Date: May 16, 1942
Creator: Cohen, Doris
Partner: UNT Libraries Government Documents Department

The mean aerodynamic chord and the aerodynamic center of a tapered wing

Description: A preliminary study of pitching-moment data on tapered wings indicated that excellent agreement with test data was obtained by locating the quarter-chord point of the average chord on the average quarter-chord point of the semispan. The study was therefore extended to include most of the available data on tapered-wing models tested by the NACA.
Date: June 16, 1942
Creator: Diehl, Walter S.
Partner: UNT Libraries Government Documents Department

Requirements for Auxiliary Stiffeners Attached to Panels Under Combined Compression and Shear

Description: "Panels of aluminum alloy sheets, framed by side and end stiffeners, were subjected to combined loading by means of offset knife edges applying loads to top and bottom end plates with reacting forces against the end plates supplied by laterally acting rollers. The test specimens were 17S-T aluminum alloy shoots 0.040 inch thick in panels of 10-inch width and three different lengths (approximately 10, 26, and 30 inch). Data were obtained for the bowing of transverse and longitudinal ribs of rectangular cross section and varying depths mounted on one side of the sheet only, for several ratios of compression to shear loads" (p. 1).
Date: September 16, 1943
Creator: Scott, Merit & Weber, Robert L.
Partner: UNT Libraries Government Documents Department

Detail Calculations of the Estimated Shift in Stick-Fixed Neutral Point Due to the Windmilling Propeller and to the Fuselage of the Republic XF-12 Airplane

Description: Detail calculations are presented of the shifts in stick-fixed neutral point of the Republic XF-12 airplane due to the windmilling propellers and to the fuselage. The results of these calculations differ somewhat from those previously made for this airplane by Republic Aviation Corporation personnel under the direction of Langley flight division personnel. Due to these differences the neutral point for the airplane is predicted to be 37.8 percent mean aerodynamic chord, instead of 40.8 percent mean aerodynamic chord as previously reported.
Date: October 16, 1944
Creator: White, M. D.
Partner: UNT Libraries Government Documents Department

Tests of an adjustable-area exhaust nozzle for jet-propulsion engines

Description: Report discussing a comparison between a centrifugal-flow-type turbojet engine with an adjustable-area exhaust nozzle and with a series of fixed-area nozzles of various throat diameters. The adjustable-area nozzle was found to be as efficient as the fixed-area nozzles in testing. Information about the corrected static thrust, fuel flow, and tail-pipe gas temperature for both types of nozzles is provided.
Date: August 16, 1945
Creator: Wilcox, E. C.
Partner: UNT Libraries Government Documents Department

NACA Investigation of Fuels Corresponding to Specification an-F-58 : Results of Studies in Single Combustors of J-33, J-34, J-35, and Nene Turbojet Engines

Description: "The NACA is engaged in a program to evaluate the performance of fuels conforming to AN-F-58 specification in both full-scale engines and single combustors. This research memorandum constitutes an interim report on the results obtained on single cosibustors" (p. 1).
Date: November 16, 1945
Creator: Cleveland Laboratory Staff
Partner: UNT Libraries Government Documents Department

Tests of a 1/7-Scale Semispan Model of the XB-35 Airplane in the Langley 19-Foot Pressure Tunnel

Description: From Summary: "A 1/7 scale semispan model of the XB-35 airplane was tested in the Langley 10 foot pressure tunnel, primarily for the purpose of investigating the effectiveness of a leading-edge slot for alleviation of stick-fixed longitudinal instability at high angles of attack caused by early tip stalling and a device for relief of stick-free instability caused by elevon up-floating tendencies at high angles of attack. Results indicated that the slot was not adequate to provide the desired improvement in stick-fixed stability."
Date: January 16, 1946
Creator: Teplitz, Jerome; Kayten, Gerald G. & Cancro, Patrick A.
Partner: UNT Libraries Government Documents Department

Effect of Compressibility at High Subsonic Velocities on the Lifting Force Acting on an Elliptic Cylinder

Description: An extended form of the Ackeret iteration method, applicable to arbitrary profiles, is utilized to calculate the compressible flow at high subsonic velocities past an elliptic cylinder. The angle of attack to the direction of the undisturbed stream is small and the circulation is fixed by the Kutta condition at the trailing end of the major axis. The expression for the lifting force on the elliptic cylinder is derived and shows a first-step improvement of the Prandtl-Glauert rule. It is further shown that the expression for the lifting force, although derived specifically for an elliptic cylinder, may be extended to arbitrary symmetrical profiles.
Date: May 16, 1946
Creator: Kaplan, Carl
Partner: UNT Libraries Government Documents Department

Altitude Cooling Investigation of the R-2800-21 Engine in the P-47G Airplane 4 - Engine Cooling-Air Pressure Distribution

Description: "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).
Date: January 16, 1947
Creator: Kaufman, Samuel J.; Staudt, Robert C. & Valerino, Michael F.
Partner: UNT Libraries Government Documents Department

A Device for Measuring Sonic Velocity and Compressor Mach Number

Description: "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).
Date: January 16, 1947
Creator: Huber, Paul W. & Kantrowitz, Arthur
Partner: UNT Libraries Government Documents Department

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

Description: "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).
Date: January 16, 1947
Creator: Standahar, Ray M. & McCarty, James S.
Partner: UNT Libraries Government Documents Department

[Memorandums on the Subject of D-558 Airplane]

Description: "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).
Date: January 16, 1947
Creator: Pendley, Robert E.
Partner: UNT Libraries Government Documents Department

Wind-Tunnel Tests of a 1/4-Scale Model of the Naval Aircraft Factory Float-Wing Convoy Interceptor, TED No. NACA 2314

Description: 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.
Date: January 16, 1947
Creator: Wells, Evalyn G. & McKinney, Elizabeth G.
Partner: UNT Libraries Government Documents Department

A Theoretical Investigation of Hydrodynamic Impact Loads on Scalloped-Bottom Seaplanes and Comparisons With Experiment

Description: "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).
Date: April 16, 1947
Creator: Milwitzky, Benjamin
Partner: UNT Libraries Government Documents Department

Effect of engine skew on directional and lateral control characteristics of single-engine airplanes

Description: 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.
Date: May 16, 1947
Creator: Wallace, Arthur R. & Comenzo, Raymond J.
Partner: UNT Libraries Government Documents Department

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

Description: 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.
Date: June 16, 1947
Creator: Ellerbrock, Herman H., Jr.
Partner: UNT Libraries Government Documents Department

Flight Tests of a Curtiss No. 838-1C2-18 Three-Blade Propeller Having Trailing-Edge Extensions

Description: 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. At an airplane Mach number of 0.7 there is a gain of 9 percent in propeller efficiency when the power coefficient per blade is increased from 0.06 to 0.09. Optimum power coefficient per blade at this Mach number is estimated to be approximately 0.12. An analysis to determine the effect of the addition of extensions on the performance of the basic propeller blades indicates that climb performance was increased but high-speed performance was reduced. Both effects, however, were small.
Date: July 16, 1947
Creator: Gardner, John J.
Partner: UNT Libraries Government Documents Department

Performance investigation of a Jumo 004 combustor

Description: 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.
Date: July 16, 1947
Creator: Miller, Robert C.
Partner: UNT Libraries Government Documents Department

Preliminary results of a flight investigation to determine the effect of negative flap deflection on high-speed longitudinal-control characteristics

Description: 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.
Date: December 16, 1947
Creator: White, Maurice D.; Sadoff, Melvin; Clousing, Lawrence A. & Cooper, George E.
Partner: UNT Libraries Government Documents Department

A suggested method of analyzing for transonic flutter of control surfaces based on available experimental evidence

Description: 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.
Date: December 16, 1947
Creator: Erickson, Albert L. & Stephenson, Jack D.
Partner: UNT Libraries Government Documents Department

Effect of Length-Beam Ratio on the Aerodynamic Characteristics of Flying-Boat Hulls without Wing Interference

Description: Contains experimental results of an investigation of the aerodynamic characteristics of a family of flying boat hulls of length beam ratios 6, 9, 12, and 15 without wing interference. The results are compared with those taken on the same family of hulls in the presence of a wing.
Date: January 16, 1948
Creator: Lowry, John G. & Riebe, John M.
Partner: UNT Libraries Government Documents Department

Free-Spinning-Tunnel Tests of a 1/29-Scale Model of the Republic XP-91 Airplane with a Vee Tail Installed

Description: A spin investigation has been conducted in the Langley 20 -foot free-spinning tunnel on a 1/29 - scale model of the Republic XP-91 airplane with vee tail installed. The effects cf control settings and movements upon the effect spin and recovery characteristics of the model were determined for the clean condition (wing tanks removed, landing gear and flaps retracted). The tests were made at a loading simulating that following cruise at altitude and at a time when nearly all fuel was expended. The results indicated that the airplane might not spin at normal spinning-control configuration, but if a spin were obtained, recovery therefrom by full rudder reversal would be satisfactory. It was also indicated that aileron-against settings would lead to violent oscillatory motions and should be avoided.
Date: January 16, 1948
Creator: Snyder, Thomas L.
Partner: UNT Libraries Government Documents Department