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open access

Air forces and moments on triangular and related wings with subsonic leading edges oscillating in supersonic potential flow

Description: From Introduction: "This report is concerned with the derivation of expressions for the velocity potential and associated forces and moments for oscillating triangular wings in supersonic flow. The purpose of the present report is to make use of the expanded form of the velocity potential to obtain the forces and moments, based on the first terms of this potential, for a rigid triangular wing performing vertical and pitching sinusoidal oscillations in mixed supersonic flow."
Date: June 19, 1951
Creator: Watkins, Charles E. & Berman, Julian H.
open access

Analysis of means of improving the uncontrolled lateral motions of personal airplanes

Description: From Summary: "A theoretical analysis has been made of means of improving the uncontrolled motions of personal airplanes. The purpose of this investigation was to determine whether such airplanes could be made to fly uncontrolled for an indefinite period of time without getting into dangerous attitudes and for a reasonable period of time (1 to 3 min) without deviating excessively from their original course. The results of this analysis indicated that the uncontrolled motions of a personal airpl… more
Date: 1951
Creator: McKinney, Marion O., Jr.
open access

Analysis of plane-plastic stress problems with axial symmetry in strain-hardening range

Description: From Introduction: "A simple method of solving plane-plastic-stress problems with axial symmetry in the strain-hardening range for finite strains were developed at the NACA Lewis laboratory during 1949-1950. This method is based on the deformation theory of Hencky and Nadai (references 7 to 9), which is derived for the condition of constant directions and ratios of the principal stresses during loading."
Date: 1951
Creator: Wu, M. H. Lee
open access

An Analysis of the Effects of Aeroelasticity on Static Longitudinal Stability and Control of a Swept-Wing Airplane

Description: From Introduction: "The results of the aforementioned study are presented in this report together with the method of analysis employed. The net stability change is shown together with the individual contributions due to flexibility of wing, tail, and fuselage, both including and neglecting the effect of inertial loads."
Date: March 19, 1951
Creator: Skoog, Richard B.
open access

Analysis of the effects of boundary-layer control in the take-off and power-off landing performance characteristics of a liaison type of airplane

Description: From Summary: "A performance analysis has been made to determine whether boundary-layer control by suction might reduce the minimum take-off and landing distances of a four-place or five-place airplane or a liaison type of airplane below those obtainable with conventional high-lift devices. The airplane was assumed to have a cruise duration of 5 hours at 60-percent power and to be operating from airstrips having a ground friction coefficient of 0.2 or a combined ground and braking coefficient o… more
Date: 1951
Creator: Horton, Elmer A.; Loftin, Laurence K., Jr.; Racisz, Stanley F. & Quinn, John H., Jr.
open access

Analysis of the effects of wing interference on the tail contributions to the rolling derivatives

Description: From Introduction: "This report presents calculations of the angularity of the air stream with respect to the vertical tail for a rolling airplane, the interference effects of the wing being taken into account. A discussion of the factors which enter into the calculations is given and equations for applying the side-wash results to the determination of the tail contributions to the rolling-stability derivatives are included. The results are compared with some available experimental data."
Date: January 24, 1951
Creator: Michael, William H., Jr.
open access

Analytical determination of coupled bending-torsion vibrations of cantilever beams by means of station functions

Description: From Summary: "A method based on the concept of Station Functions is presented for calculating the modes and the frequencies of nonuniform cantilever beams vibrating in torsion, bending, and coupled bending-torsion motion. The method combines some of the advantages of the Rayleigh-Ritz and Stodola methods, in that a continuous loading function for the beam is used, with the advantages of the influence-coefficient method, in that the continuous loading function is obtained in terms of the displa… more
Date: 1951
Creator: Mendelson, Alexander & Gendler, Selwyn
open access

Application of a channel design method to high-solidity cascades and tests of an impulse cascade with 90 degrees of turning

Description: From introduction: "A technique for application of the channel design methods of reference 11 to the design of high-solidity cascades with prescribed velocity distributions as a function of arc length along the blade-element profiles is presented herein."
Date: November 30, 1951
Creator: Stanitz, John D. & Sheldrake, Leonard J.
open access

A biharmonic relaxation method for calculating thermal stress in cooled irregular cylinders

Description: A numerical method was developed for calculating thermal stresses in irregular cylinders cooled by one or more internal passages. The use of relaxation methods and elementary methods of finite differences was found to give approximations to the correct values when compared with previously known solutions for concentric circular cylinders possessing symmetrical and asymmetrical temperature distributions.
Date: May 10, 1951
Creator: Holms, Arthur G.
open access

Buckling of thin-walled cylinder under axial compression and internal pressure

Description: An investigation was made of a thin-walled cylinder under axial compression and various internal pressures to study the effect of the internal pressure on the compressive buckling stress of the cylinder. A theoretical analysis based on a large-deflection theory was also made. The theoretically predicted increase of compressive buckling stress due to internal pressure agrees fairly well with the experimental results. (author).
Date: 1951
Creator: Lo, Hsu; Crate, Harold & Schwartz, Edward B.
open access

Calculation of the lateral control of swept and unswept flexible wings of arbitrary stiffness

Description: A method similar to that of NACA rep. 1000 is presented for calculating the effectiveness and the reversal speed of lateral-control devices on swept and unswept wings of arbitrary stiffness. Provision is made for using either stiffness curves and root-rotation constants or structural influence coefficients in the analysis. Computing forms and an illustrative example are included to facilitate calculations by means of the method. The effectiveness of conventional aileron configurations and the m… more
Date: April 5, 1951
Creator: Diederich, Franklin W.
open access

Calculations of Laminar Heat Transfer Around Cylinders of Arbitrary Cross Section and Transpiration-Cooled Walls With Application to Turbine Blade Cooling

Description: "An approximate method for the development of flow and thermal boundary layers in the laminar region on cylinders with arbitrary cross section and transpiration-cooled walls is obtained by the use of Karman's integrated momentum equation and an analogous heat-flow equation. Incompressible flow with constant property values throughout the boundary layer is assumed. The velocity and temperature profiles within the boundary layer are approximated by expressions composed of trigonometric functions"… more
Date: June 22, 1951
Creator: Eckert, E. R. G. & Livingood, J. N. B.
open access

Calculations on the forces and moments for an oscillating wing-aileron combination in two-dimensional potential flow at sonic speed

Description: From Summary: "The linearized theory for compressible unsteady flow is used, as suggested in recent contributions to the subject, to obtain the velocity potential and the lift and moment for a thin harmonically oscillating, two-dimensional wing-aileron combination moving at sonic speed. The velocity potential is derived by considering the sonic case as the limit of the linearized supersonic theory. From the velocity potential explicit expressions for the lift and moment are developed for vertic… more
Date: September 4, 1951
Creator: Nelson, Herbert C. & Berman, Julian H.
open access

A comparison of the experimental subsonic pressure distributions about several bodies of revolution with pressure distributions computed by means of the linearized theory

Description: "An analysis is made of the effects of compressibility on the pressure coefficients about several bodies of revolution by comparing experimentally determined pressure coefficients with corresponding pressure coefficients calculated by the use of the linearized equations of compressible flow. The results show that the theoretical methods predict the subsonic pressure-coefficient changes over the central part of the body but do not predict the pressure-coefficient changes near the nose. Extrapola… more
Date: November 5, 1951
Creator: Matthews, Clarence W.
open access

A Comparison of the Spanwise Loading Calculated by Various Methods With Experimental Loadings Obtained on a 45 Degree Sweptback Wing of Aspect Ratio 8.02 at a Reynolds Number of 4.0 X 10(6)

Description: "This report compares the experimental force and moment data obtained by pressure measurements on a wing of aspect ratio 8.02, 45 degree sweptback of the quarter-chord line, taper ratio of 0.45, and NACA 63(sub 1)A012 airfoil sections with the calculated loadings obtained by the standard methods proposed by Weissinger, Falkner, and Multopp, as well as by several variations of these methods" (p. 1175).
Date: August 14, 1951
Creator: Schneider, William C.
open access

Compressive strength of flanges

Description: The maximum compressive stress carried by a hinged flange is computed from a deformation theory of plasticity combined with the theory for finite deflections for this structure. The computed stresses agree well with those found experimentally. Empirical observation indicates that the results will also apply fairly well to the more commonly used flanges which are not hinged.
Date: 1951
Creator: Stowell, Elbridge Z.
open access

A correlation by means of transonic similarity rules of experimentally determined characteristics of a series of symmetrical and cambered wings of rectangular plan form

Description: Transonic similarity rules are applied to the correlation of experimental data for a series of related rectangular wings of varying aspect ratio, thickness, and camber. The data correlation is presented in two parts: the first part presents the correlation for a series of 22 wings having symmetrical NACA 63a-series sections; the second part is concerned with a study of one type of camber by correlation of the data for a series of 18 cambered wings having NACA 63a2xx and 63a4xx sections.
Date: December 17, 1951
Creator: McDevitt, John B.
open access

Correlation of physical properties with molecular structure for some dicyclic hydrocarbons having high thermal-energy release per unit volume -- 2-alkylbiphenyl and the two isomeric 2-alkylbicyclohexyl series

Description: Three homologous series of related dicyclic hydrocarbons are presented for comparison on the basis of their physical properties, which include net heat of combustion, density, melting point, boiling point, and kinematic viscosity. The three series investigated include the 2-n-alkylbiphenyl, 2-n-alkylbicyclohexyl (high boiling), and 2-n-alkylbiphenyls (low boiling) series through c sub 16, in addition to three branched-chain (isopropyl, sec-butyl, and isobutyl) 2-alkylbiphenyls and their corresp… more
Date: January 25, 1951
Creator: Goodman, Irving A. & Wise, Paul H.
open access

Design of two-dimensional channels with prescribed velocity distributions along the channel walls

Description: "A general method of design is developed for two-dimensional unbranched channels with prescribed velocities as a function of arc length along the channel walls. The method is developed for both compressible and incompressible, irrotational, nonviscous flow and applies to the design of elbows, diffusers, nozzles, and so forth. In part I solutions are obtained by relaxation methods; in part II solutions are obtained by a Green's function. Five numerical examples are given in part I including thre… more
Date: July 25, 1951
Creator: Stanitz, John D.
open access

Diffusion of chromium in alpha cobalt-chromium solid solutions

Description: Diffusion of chromium in cobalt-chromium solid solutions was investigated in the range 0 to 40 atomic percent at temperatures of 1360 degrees, 1300 degrees, 1150 degrees, and 10000 degrees c. The diffusion coefficients were found to be relatively constant within the composition range covered by each specimen. The activation heat of diffusion was determined to be 63,000 calories per mole. This value agrees closely with the value of 63,400 calories per mole calculated by means of the Dushman-Lang… more
Date: 1951
Creator: Weeton, John W.
open access

Diffusion of heat from a line source in isotropic turbulence

Description: "An experimental and analytical study has been made of some features of the turbulent heat diffusion behind a line heated wire stretched perpendicular to a flowing isotropic turbulence. The mean temperature distributions have been measured with systematic variations in wind speed, size of turbulence-producing grid, and downstream location of heat source. The nature of the temperature fluctuation field has been studied" (p. 1).
Date: June 5, 1951
Creator: Uberoi, Mahinder S. & Corrsin, Stanley
open access

Direct Measurements of Skin Friction

Description: "A device has been developed to measure local skin friction on a flat plate by measuring the force exerted upon a very small movable part of the surface of the flat plate. These forces, which range from about 1 milligram to about 100 milligrams, are measured by means of a reactance device. The apparatus was first applied to measurements in the low-speed range, both for laminar and turbulent boundary layers. The device was then applied to high-speed subsonic flow and the turbulent-skin-friction … more
Date: June 1, 1951
Creator: Dhawan, Satish
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