National Advisory Committee for Aeronautics (NACA) - 1,963 Matching Results

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AVA monographs. B: Boundary layer

Description: Report discusses several experiments regarding boundary layers and their influence on aircraft. The first experiment investigates how to best design airfoils. The second involves using suction to remove the boundary layer. The third involves surface disturbances and how they may affect the boundary layer.
Date: April 1, 1948
Creator: Holstein, H.; Bete, A. & Tollmein, W.
Partner: UNT Libraries Government Documents Department

Moments of cambered round bodies

Description: Results are presented for the moments and position of force centers of a series of cambered round bodies derived from a torpedo-like body of revolution. The effects of placing fins on the rear of the body of revolution are also included.
Date: August 1, 1949
Creator: Kempf, Gunther
Partner: UNT Libraries Government Documents Department

Effects of sweepback on boundary layer and separation

Description: Following the law of stress adopted in the Navier-Stokes equations, the configuration of the viscous flow in planes at right angles to the axis of an infinite cylinder is found to be independent of the axial motion of the cylinder. In the limiting case of a yawed or swept wing of very high aspect ratio, certain boundary-layer and separation phenomena are thus determined independently by the crosswise component of velocity.
Date: July 1, 1947
Creator: Jones, Robert T
Partner: UNT Libraries Government Documents Department

Elastic properties in tension and shear of high strength nonferrous metals and stainless steel - effect of previous deformation and heat treatment

Description: A resume is given of an investigation of the influence of plastic deformation and of annealing temperature on the tensile and shear elastic properties of high strength nonferrous metals and stainless steels in the form of rods and tubes. The data were obtained from earlier technical reports and notes, and from unpublished work in this investigation. There are also included data obtained from published and unpublished work performed on an independent investigation. The rod materials, namely, nickel, monel, inconel, copper, 13:2 Cr-Ni steel, and 18:8 Cr-Ni steel, were tested in tension; 18:8 Cr-Ni steel tubes were tested in shear, and nickel, monel, aluminum-monel, and Inconel tubes were tested in both tension and shear. There are first described experiments on the relationship between hysteresis and creep, as obtained with repeated cyclic stressing of annealed stainless steel specimens over a constant load range. These tests, which preceded the measurements of elastic properties, assisted in devising the loading time schedule used in such measurements. From corrected stress-set curves are derived the five proof stresses used as indices of elastic or yield strength. From corrected stress-strain curves are derived the secant modulus and its variation with stress. The relationship between the forms of the stress-set and stress-strain curves and the values of the properties derived is discussed. Curves of variation of proof stress and modulus with prior extension, as obtained with single rod specimens, consist in wavelike basic curves with superposed oscillations due to differences of rest interval and extension spacing; the effects of these differences are studied. Oscillations of proof stress and modulus are generally opposite in manner. The use of a series of tubular specimens corresponding to different amounts of prior extension of cold reduction gave curves almost devoid of oscillation since the effects of variation of rest interval and extension spacing ...
Date: March 1, 1947
Creator: Mebs, R W & Mcadam, D J
Partner: UNT Libraries Government Documents Department