National Advisory Committee for Aeronautics (NACA) - 2,226 Matching Results

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Tables for the Computation of Wave Drag of Arrow Wings of Arbitrary Airfoil Section

Description: Tables and computing instructions for the rapid evaluation of the wave drag of delta wings and of arrow wings having a ration of the tangent of the trailing-edge sweep angle to the tangent of the leading-edge sweep angle in the range from -1.0 to 0.8. The tables cover a range of both subsonic and supersonic leading edges.
Date: June 1954
Creator: Grant, Fredrick C. & Cooper, Morton
Partner: UNT Libraries Government Documents Department

Two-dimensional subsonic compressible flows past arbitrary bodies by the variational method

Description: Instead of solving the nonlinear differential equation which governs the compressible flow, an approximate method of solution by means of the variational method is used. The general problem of steady irrotational flow past an arbitrary body is formulated. Two examples were carried out, namely, the flow past a circular cylinder and the flow past a thin curved surface. The variational method yields results of velocity and pressure distributions which compare excellently with those found by existing methods. These results indicate that the variational method will yield good approximate solution for flow past both thick and thin bodies at both high and low Mach numbers.
Date: March 1951
Creator: Wang, Chi-Teh
Partner: UNT Libraries Government Documents Department

Reciprocity relations in aerodynamics

Description: From Introduction: "The purpose of the present paper is twofold. First, a close connection will be established between reverse-flow theorems in subsonic and supersonic, steady-state wing theory and known reciprocity relations between two solutions of the equation the flow field."
Date: May 1952
Creator: Spreiter, John R & Heaslet, Max A
Partner: UNT Libraries Government Documents Department

A low-speed experimental investigation of the effect of a sandpaper type of roughness on boundary-layer transition

Description: Report describing the effects of an area of roughness on the velocity and turbulence measurements of an airfoil. It details the effects of the size, location, and height of the roughness on the Reynolds number. From Summary: "An investigation was made in the Langley low-turbulence pressure tunnel to determine the effect of size and location of a sandpaper type of roughness on the Reynolds number for transition."
Date: 1958
Creator: Horton, Elmer A. & von Doenhoff, Albert E.
Partner: UNT Libraries Government Documents Department

Acoustic, thrust, and drag characteristics of several full-scale noise suppressors for turbojet engines

Description: From Introduction: " Considerable analytical and experimental research has been done to find means of reducing the noise levels of the turbojet transports. Noise levels can be decreased by engine redesign to reduce the jet-exit velocity (ref. 1), proper flight-climb techniques (ref. 2), and the use of noise-suppression exhaust nozzles (refs. 3 to 5). The present report is concerned with the last method."
Date: April 1958
Creator: Ciepluch, Carl C; North, Warren J; Coles, Willard D & Antl, Robert J
Partner: UNT Libraries Government Documents Department

Acoustical treatment for the NACA 8- by 6-foot supersonic propulsion wind tunnel

Description: From Introduction: "This report presents results of a research and engineering program performed during the first half of 1950 that resulted in an acoustical treatment for the 8- by 6-foot supersonic wind tunnel at the Lewis Flight Propulsion Laboratory."
Date: June 1955
Creator: Beranek, Leo L; Labate, Samuel & Ingard, Uno
Partner: UNT Libraries Government Documents Department

Calculation and compilation of the unsteady-lift functions for a rigid wing subjected to sinusoidal gusts and to sinusoidal sinking oscillations

Description: The total lift responses to sinusoidal sinking oscillations and to sinusoidal gusts have been calculated, largely from existing information, for wings of various plan forms in subsonic and supersonic flow. For most of the cases considered, closed-form expressions are given and the final results are presented in the form of plots of the square of the modulus of the lift coefficient for wings in a sinusoidally oscillating gust field and in the form of the real and imaginary parts of the lift coefficient for wings undergoing sinusoidal sinking oscillations.
Date: October 1, 1956
Creator: Drischler, Joseph A
Partner: UNT Libraries Government Documents Department

Charts adapted from Van Driest's turbulent flat-plate theory for determining values of turbulent aerodynamic friction and heat-transfer coefficients

Description: A modified method of Van Driest's flat-plate theory for turbulent boundary layer has been found to simplify the calculation of local skin-friction coefficients which, in turn, have made it possible to obtain through Reynolds analogy theoretical turbulent heat-transfer coefficients in the form of Stanton number. A general formula is given and charts are presented from which the modified method can be solved for Mach numbers 1.0 to 12.0, temperature ratios 0.2 to 6.0, and Reynolds numbers 0.2 times 10 to the 6th power to 200 times 10 to the 6th power.
Date: October 1, 1956
Creator: Lee, Dorothy B & Faget, Maxime A
Partner: UNT Libraries Government Documents Department

Charts for estimating the hovering endurance of a helicopter

Description: As a means of comparing the performance capabilities of various helicopter propulsion systems, charts have been presented for estimating the hovering endurance of a helicopter in the form of a hovering-endurance parameter as a function of the ratio of total fuel load to helicopter initial weight for a range of initial thrust coefficients from 0.002 to 0.012 and for values of rotor mean lift coefficient from 0.24 to .072. The charts were presented for a helicopter having rotor blades with ideal twist. However, corrections may be applied to the hovering endurance to account for other combinations of twist and taper. The effects of stall and compressibility have been neglected.
Date: October 1, 1956
Creator: Makofski, Robert A
Partner: UNT Libraries Government Documents Department