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open access

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 rect… more
Date: September 16, 1943
Creator: Scott, Merit & Weber, Robert L.
open access

Static longitudinal aerodynamic characteristics of a 52 degree sweptback wing of aspect ratio 2.88 at Reynolds numbers from 2,000,000 to 11,000,000

Description: Report presenting the effects of changes in Reynolds number on the longitudinal aerodynamic characteristics of a 52 degree sweptback wing with an aspect ratio of 2.88 and NACA 64(sub 1)-112 airfoil sections. The model was tested with the leading edge both smooth and rough. Results regarding force and pitching-moment results, flow observations, and discussion of force and moment characteristics are provided.
Date: November 16, 1948
Creator: Fitzpatrick, James E. & Foster, Gerald V.
open access

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-press… more
Date: September 16, 1948
Creator: Cook, William P. & Zettle, Eugene V.
open access

Wind-Tunnel Investigation of Horizontal Tails 4: Unswept Plan Form of Aspect Ratio 2 and a Two-Dimensional Model

Description: Memorandum presenting the results of a wind-tunnel investigation of the low-speed aerodynamic characteristics of a horizontal-tail model of aspect ratio 2 with an unswept plan form and of a two-dimensional model. The two-dimensional model provides data which can be used as the basis for computing the three-dimensional lift and hinge-moment parameters by the lifting-surface-theory procedure. Results regarding the effectiveness and hinge-moment parameters, static longitudinal stability, scale eff… more
Date: December 16, 1948
Creator: Dods, Jules B., Jr.
open access

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.
open access

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

Description: "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" (p. 5).
Date: August 16, 1948
Creator: Bowman, William D
open access

On Reflection of Shock Waves from Boundary Layers

Description: Measurements are presented at Mach numbers from about 1.3 to 1.5 of reflection characteristics and the relative upstream influence of shock waves impinging on a flat surface with both laminar and turbulent boundary layers. The difference between impulse and step waves is discussed and their interaction with the boundary layer is compared. General considerations on the experimental production of shock waves from wedges and cones and examples of reflection of shock waves from supersonic shear lay… more
Date: August 16, 1949
Creator: Liepmann, H. W.; Roshko, A. & Dhawan, S.
open access

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.
open access

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.
open access

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 … more
Date: May 16, 1942
Creator: Cohen, Doris
open access

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… more
Date: May 16, 1946
Creator: Kaplan, Carl
open access

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
open access

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.
open access

Altitude-wind-tunnel investigation of various can-type burners in Bumblebee 18-inch ram jet

Description: An investigation on various can-type burners in a Bumblebee 18-inch ram jet under controlled conditions of pressure altitude and ram pressure ratio was conducted in the NACA Lewis altitude wind tunnel with kerosene as fuel. The performance of the following can-type burner configurations was better than that of the other burner configurations investigated: (1) a flame holder having a two-pitch alinement of perforations, 0.07-inch-wide cooling slots, and an arrangement of fuel nozzles located wit… more
Date: March 16, 1949
Creator: Dupree, D. T.; Nussdorfer, T. J. & Sterbentz, W. H.
open access

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 inters… more
Date: January 16, 1947
Creator: Standahar, Ray M. & McCarty, James S.
open access

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.
open access

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.
open access

[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., represe… more
Date: January 16, 1947
Creator: Pendley, Robert E.
open access

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 2… more
Date: July 16, 1947
Creator: Gardner, John J.
open access

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.
open access

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 wa… more
Date: August 16, 1948
Creator: Kovach, Karl & Withee, Joseph R., Jr.
open access

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 im… more
Date: January 16, 1946
Creator: Teplitz, Jerome; Kayten, Gerald G. & Cancro, Patrick A.
open access

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 of 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" (… more
Date: January 16, 1948
Creator: Snyder, Thomas L.
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