Technical Report Archive and Image Library (TRAIL) - 16 Matching Results

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Force measurements on a 1/40-scale model of the U. S. Airship "Akron"

Description: This report describes a series of tests made on a 1/40-scale model of the U. S. Airship "Akron" (ZRS-4) for the purpose of determining the drag, lift, and pitching moments of the bare hull and of the hull equipped with two different sets of fins. Measurements were also made of the elevator forces and hinge moments.
Date: May 6, 1932
Creator: Freeman, Hugh B.
Partner: UNT Libraries Government Documents Department

A photographic study of combustion and knock in a spark-ignition engine

Description: Report presents the results of a photographic study of the combustion in a spark-ignition engine using both Schlieren and flame photographs taken at high rates of speed. Although shock waves are present after knock occurs, there was no evidence of any type of sonic or supersonic compression waves existing in the combustion gases prior to the occurrence of knock. Artificially induced shock waves in the engine did not in themselves cause knock.
Date: December 6, 1937
Creator: Rothrock, A. M. & Spencer, R. C.
Partner: UNT Libraries Government Documents Department

Air Flow in the Boundary Layer of an Elliptic Cylinder

Description: From Introduction: "The present investigation was carried out for the purpose of supplementing the earlier work with information on the boundary layer under such conditions of air speed and turbulence that transition occurs and the layer is partly laminar and partly turbulent. In the work reported in reference 1, the air speed was about 12 feet per second, and it was assumed that the boundary layer remained in the laminar condition until after separation because the separation point remained fixed and the pressure distribution about the cylinder was unaffected until an air speed of 15 feet per second was reached."
Date: August 6, 1938
Creator: Schubauer, G. B.
Partner: UNT Libraries Government Documents Department

Determination of the Profile Drag of an Airplane Wing in Flight at High Reynolds Numbers

Description: "Flight tests were made to determine the profile-drag coefficients of a portion of the original wing surface of an all-metal airplane and of a portion of the wing made aerodynamically smooth and more nearly fair than the original section. The wing section was approximately the NACA 2414.5. The tests were carried out over a range of airplane speeds giving a maximum Reynolds number of 15,000,000. Tests were also carried out to locate the point of transition from laminar to turbulent boundary layer and to determine the velocity distribution along the upper surface of the wing" (p. 483).
Date: January 6, 1939
Creator: Bicknell, Joseph
Partner: UNT Libraries Government Documents Department

Piston temperatures in an air-cooled engine for various operating conditions

Description: As part of a program for the study of piston cooling, this report presents the results of tests conducted on a single-cylinder, air-cooled, carburetor engine to determine the effect of engine operating conditions on the temperatures at five locations on the piston.
Date: April 6, 1940
Creator: Manganiello, Eugene J.
Partner: UNT Libraries Government Documents Department

The NACA high-speed motion-picture camera optical compensation at 40,000 photographs per second

Description: The principle of operation of the NACA high-speed camera is completely explained. This camera, operating at the rate of 40,000 photographs per second, took the photographs presented in numerous NACA reports concerning combustion, preignition, and knock in the spark-ignition engine. Many design details are presented and discussed, details of an entirely conventional nature are omitted. The inherent aberrations of the camera are discussed and partly evaluated. The focal-plane-shutter effect of the camera is explained. Photographs of the camera are presented. Some high-speed motion pictures of familiar objects -- photoflash bulb, firecrackers, camera shutter -- are reproduced as an illustration of the quality of the photographs taken by the camera.
Date: November 6, 1945
Creator: Miller, Cearcy D.
Partner: UNT Libraries Government Documents Department

Analysis of Performance of Jet Engine From Characteristics of Components 1: Aerodynamic and Matching Characteristics of Turbine Component Determined With Cold Air

Description: "The performance of the turbine component of an NACA research jet engine was investigated with cold air. The interaction and the matching of the turbine with the NACA eight-stage compressor were computed with the combination considered as a jet engine. The over-all performance of the engine was then determined. The internal aerodynamics were studied to the extent of investigating the performance of the first stator ring and its influence on the turbine performance" (p. 397).
Date: June 6, 1947
Creator: Goldstein, Arthur W.
Partner: UNT Libraries Government Documents Department

Stability derivatives of triangular wings at supersonic speeds

Description: "The analysis of the stability derivatives of low-aspect-ratio triangular wings at subsonic and supersonic speeds, given in NACA TN no. 1423, is extended to apply to triangular wings having large vertex angles and traveling at supersonic speeds. The lift, rolling moment due to sideslip, and damping in roll and pitch for this more general case have been treated elsewhere on the basis of the theory of small disturbances. The surface potentials for angle of attack and rolling taken therefrom are used to obtain the several side-force and yawing-moment derivatives that depend on leading-edge suction, and a tentative value for the rolling moment due to yawing" (p. 317).
Date: November 6, 1947
Creator: Ribner, Herbert S. & Malvestuto, Frank S., Jr.
Partner: UNT Libraries Government Documents Department

Aerodynamic characteristics at high speeds of related full-scale propellers having different blade-section cambers

Description: From Summary: "Wind-tunnel tests of a full-scale two-blade NACA 10-(10)(08)-03 (high camber) propeller have been made for a range of blade angles from 20 degrees to 55 degrees at airspeeds up to 500 miles per hour. The results of these tests have been compared with results from previous tests of the NACA 10-(3) (08)-03 (low camber) and NACA 10-(5)(08)-03 (medium camber) propellers to evaluate the effects of blade-section camber on propeller aerodynamic characteristics."
Date: May 6, 1948
Creator: Maynard, Julian D. & Salters, Leland B., Jr.
Partner: UNT Libraries Government Documents Department

Effect of aspect ratio on the air forces and moments of harmonically oscillating thin rectangular wings in supersonic potential flow

Description: This report treats the effect of aspect ratio on the air forces and moments of an oscillating flat rectangular wing in supersonic potential flow. The linearized velocity potential for the wing undergoing sinusoidal torsional oscillations simultaneously with sinusoidal vertical translations is derived in the form of a power series in terms of a frequency parameter. The series development is such that the differential equation for the velocity potential is satisfied to the required power of the frequency parameter considered and the linear boundary conditions are satisfied exactly. The method of solution can be utilized for other plan forms, that is, plan forms for which certain steady-state solutions are known.
Date: January 6, 1950
Creator: Watkins, Charles E.
Partner: UNT Libraries Government Documents Department

Displacement Effect of a Three-Dimensional Boundary Layer

Description: "A method is described for determining the "displacement surface" of known three-dimensional compressible boundary-layer flow in terms of the mass-flow defects associated with the profiles of the two velocity components parallel to the surface. The result is a generalization of the plane flow concept of displacement thickness introduced in order to describe how a thin boundary layer distorts the outer nonviscous flow. Numerical values are found for the known three-dimensional boundary-layer flow about a cone at a small angle of attack to a supersonic stream" (p. 367).
Date: March 6, 1952
Creator: Moore, Franklin K.
Partner: UNT Libraries Government Documents Department

Theoretical and experimental investigation of mufflers with comments on engine-exhaust muffler design

Description: Equations are presented for the attenuation characteristics of single-chamber and multiple-chamber mufflers of both the expansion-chamber and resonator types, for tuned side-branch tubes, and for the combination of an expansion chamber with a resonator. Experimental curves of attenuation plotted against frequency are presented for 77 different mufflers with a reflection-free tailpipe termination. The experiments were made at room temperature without flow; the sound source was a loud-speaker. A method is given for including the tailpipe reflections in the calculations. Experimental attenuation curves are presented for four different muffler-tailpipe combinations, and the results are compared with the theory. The application of the theory to the design of engine-exhaust mufflers is discussed, and charts are included for the assistance of the designer.
Date: October 6, 1952
Creator: Davis, Don D., Jr.; Stokes, George M.; Moore, Dewey & Stevens, George L., Jr.
Partner: UNT Libraries Government Documents Department

A thermal equation for flame quenching

Description: From Summary: "An approximate thermal equation was derived for quenching distance based on a previously proposed diffusional treatment. The quenching distance was expressed in terms of the thermal conductivity, the fuel mole fraction, the heat capacity, the rate of the rate-controlling chemical reaction, a constant that depends on the geometry of the quenching surface, and one empirical constant. The effect of pressure on quenching distance was shown to be inversely proportional to the pressure dependence of the flame reaction, with small correction necessitated by the effect of pressure on flame temperature."
Date: December 6, 1954
Creator: Potter, A. E., Jr. & Berlad, A. I.
Partner: UNT Libraries Government Documents Department

Theoretical span load distributions and rolling moments for sideslipping wings of arbitrary plan form in incompressible flow

Description: From Summary: "A method of computing span loads and the resulting rolling moments for sideslipping wings of arbitrary plan form in incompressible flow is derived. The method requires that the span load at zero sideslip be known for the wing under consideration. Because this information is available for a variety of wings, this requirement should not seriously restrict the application of the present method. The basic method derived herein requires a mechanical differentiation and integration to obtain the rolling moment for the general wing in sideslip."
Date: October 6, 1955
Creator: Queijo, M. J.
Partner: UNT Libraries Government Documents Department

Experimental determination of effects of frequency and amplitude on the lateral stability derivatives for a delta, a swept, and unswept wing oscillating in yaw

Description: "Three wing models were oscillated in yaw about their vertical axes to determine the effects of systematic variations of frequency and amplitude of oscillation on the in-phase and out-of-phase combination lateral stability derivatives resulting from this motion. The tests were made at low speeds for a 60 degree delta wing, a 45 degree swept wing, and an unswept wing; the swept and unswept wings had aspect ratios of 4. The results indicate that large changes in the magnitude of the stability derivatives due to the variation of frequency occur at high angles of attack, particularly for the delta wing" (p. 461).
Date: January 6, 1956
Creator: Fisher, Lewis R.
Partner: UNT Libraries Government Documents Department

Theoretical calculation of the power spectra of the rolling and yawing moments on a wing in random turbulence

Description: The correlation functions and power spectra of the rolling and yawing moments on an airplane wing due to the three components of continuous random turbulence are calculated. The rolling moments to the longitudinal (horizontal) and normal (vertical) components depend on the spanwise distributions of instantaneous gust intensity, which are taken into account by using the inherent properties of symmetry of isotropic turbulence. The results consist of expressions for correlation functions or spectra of the rolling moment in terms of the point correlation functions of the two components of turbulence.
Date: September 6, 1956
Creator: Eggleston, John M. & Diederich, Franklin W.
Partner: UNT Libraries Government Documents Department