National Advisory Committee for Aeronautics (NACA) - 35 Matching Results

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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

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. Limiting values of the moments of inertia were calculated from these measurements. The experimental values exceed the theoretical values given by Timoshenko for the case of simply supported sheets with uniformly distributed boundary stresses. The work reported includes measurements of the effective shear moduli of the nine test panels with and without ribs. These data are compared with values published by Lahdo and Wagner.
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

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

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. Viscous effects in the orifice of the Helmholtz resonator are shown to be important and can be taken into account with the help of a parameter obtained from Stokes solution of the flow near an oscillating wall. This parameter includes the kinematic viscosity of the fluid and the frequency of sound in the resonator. When these effects are recognized, the resonator can be calibrated to measure velocity of sound or compressor Mach number to an accuracy of better than 0.5 percent.
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 III : 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. All runs were made at a constant engine speed of 3000 rpm at a simulated altitude of 29,000 feet and all changes in engine power were made by varying the speed of the auxiliary-stage supercharger.
Date: January 16, 1947
Creator: Standahar, Ray M. & Mccarty, James S.c
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

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

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

Hydrodynamic Characteristics of an Aerodynamically Refined Planing-Tail Hull

Description: The hydrodynamic characteristics of an aerodynamically refined planing-tail hull were determined from dynamic model tests in Langley tank no. 2. Stable take-off could be made for a wide range of locations of the center of gravity. The lower porpoising limit peak was high, but no upper limit was encountered. Resistance was high, being about the same as that of float seaplanes. A reasonable range of trims for stable landings was available only in the aft range of center-of-gravity locations.
Date: July 16, 1948
Creator: McKann, Robert & Suydam, Henry B.
Partner: UNT Libraries Government Documents Department

Analytical investigation of effect of water-cooled turbine blades on performance of turbine-propeller power plants

Description: From Introduction: "Finally the work of the report is applied exclusively to consideration of the turbine-propeller power plant because previous performance analyses of the various gas-turbine propulsion systems combine with recent improvements in propeller design indicate that it is this combination which, will give the best over-all performance in the speed ranges considered."
Date: August 16, 1948
Creator: Bowman, William D
Partner: UNT Libraries Government Documents Department

Calibration of Air-Flow Meters for J33 Compressor Investigation

Description: Flow-metering devices used by the NACA and by the manufacturer of the J33 turbojet engine were calibrated together to determine whether an observed discrepancy in weight flow of approximately 4 percent for the two separate investigations might be due to the different devices used to meter air flow. A commercial adjustable orifice and a square-edge flat-plate orifice used by the NACA and a flow nozzle used by the manufacturer were calibrated against surveys across the throat of the nozzle. It was determined that over a range of weight flows from 18 to 45 pounds per second the average weight flows measured by the metering device used for the compressor test would be 0.70 percent lower than those measured by the metering device used in the engine tests and the probable variation about this mean would be +/- 0.39 percent. The very close agreement of the metering devices shows that the greater part of the discrepancy in weight flow is attributable to the effect of inlet pressure.
Date: August 16, 1948
Creator: Kovach, Karl & Withee, Joseph R., Jr.
Partner: UNT Libraries Government Documents Department

Performance investigation of can-type combustor 1: instrumentation, altitude operational limits and combustion efficiency

Description: Report presenting an investigation of the performance of a single can-type combustor designed for a turbojet engine equipped with an 11-stage axial-flow compressor and a single-stage turbine. The investigation was conducted to determine the altitude operational limits of the engine for two fuels, combustion efficiencies at various simulated conditions of altitude and engine speed, combustor-outlet temperature distribution for several altitudes at constant engine speed, and combustor total-pressure drop.
Date: September 16, 1948
Creator: Cook, William P. & Zettle, Eugene V.
Partner: UNT Libraries Government Documents Department