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The Lagrangian Multiplier Method of Finding Upper and Lower Limits to Critical Stresses of Clamped Plates

Description: "The theory of Lagrangian multipliers is applied to the problem of finding both upper and lower limits to the true compressive buckling stress of a clamped rectangular plate. The upper and lower limits thus bracket the truss, which cannot be exactly found by the differential-equation approach. The procedure for obtaining the upper limit, which is believed to be new, presents certain advantages over the classical Raleigh-Rite method of finding upper limits" (p. 1).
Date: 1946
Creator: Budiansky, Bernard & Hu, Pai C.
Item Type: Refine your search to only Report
open access

Theoretical lift and drag of thin triangular wings at supersonic speeds

Description: "A method is derived for calculating the lift and the drag due to lift of point-forward triangular wings and a restricted series of sweptback wings at supersonic speeds. The elementary or "supersonic sources" solution of the linearized equation of motion is used to find the potential function of a line of doublets. The flow about the triangular flat plate is then obtained by a surface distribution of these doublet lines. The lift-curve slope of triangular wings is found to be a function of the … more
Date: November 29, 1946
Creator: Brown, Clinton E.
Item Type: Refine your search to only Report
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Application of the Method of Characteristics to Supersonic Rotational Flow

Description: "A system for calculating the physical properties of supersonic rotational flow with axial symmetry and supersonic rotational flow in a two-dimensional field was determined by use of the characteristics method. The system was applied to the study of external and internal flow for supersonic inlets with axial symmetry. For a circular conical inlet the shock that occurred at the lip of the inlet became stronger as it approached the axis of the inlet and became a normal shock at the axis" (p. 111). more
Date: April 29, 1946
Creator: Ferri, Antonio
Item Type: Refine your search to only Report
open access

Flutter and oscillating air-force calculations for an airfoil in two-dimensional supersonic flow

Description: A connected account is given of the Possio theory of non-stationary flow for small disturbances in a two-dimensional supersonic flow and of its application to the determination of the aerodynamic forces on an oscillating airfoil. Further application is made to the problem of wing flutter in the degrees of freedom - torsion, bending, and aileron rotations. Numerical tables for flutter calculations are provided for various values of the Mach number greater than unity. Results for bending-torsion … more
Date: May 29, 1946
Creator: Garrick, I. E. & Rubinow, S. I.
Item Type: Refine your search to only Report
open access

Summary of lateral-control research

Description: "A summary has been made of the available information on lateral control. A discussion is given of the criterions used in lateral-control specifications, of the factors involved in obtaining satisfactory lateral control, and of the methods employed in making lateral-control investigations in flight and in wind tunnels. The available data on conventional flap-type ailerons having various types of aerodynamic balance are presented in a form convenient for use in design. The characteristics of spo… more
Date: February 14, 1946
Creator: Toll, Thomas A.
Item Type: Refine your search to only Report
open access

The Stability of the Laminar Boundary Layer in a Compressible Fluid

Description: The present paper is a continuation of a theoretical investigation of the stability of the laminar boundary layer in a compressible fluid. An approximate estimate for the minimum critical Reynolds number, or stability limit, is obtained in terms of the distribution of the kinematic viscosity and the product of the mean density and mean vorticity across the boundary layer. The extension of the results of the stability analysis to laminar boundary-layer gas flows with a pressure gradient in the d… more
Date: September 5, 1946
Creator: Lees, Lester
Item Type: Refine your search to only Report
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Tank tests to determine the effect on planing-tail hulls of varying length, width, and plan-form taper of afterbody

Description: Tests were conducted in Langley Tank no. 2 on models of an unconventional flying-boat hull called a planing-tail hull to determine the effects on resistance of varying a number of afterbody parameters. The effects of varying length, width, and plan-form taper of the afterbody are presented. Tests were made with afterbodies of two widths, two lengths, and two tapers. In the tests the depth of step and the angle of afterbody keel were held constant.(author).
Date: January 7, 1946
Creator: Dawson, John R.; Walter, Robert C. & Hay, Elizabeth S.
Item Type: Refine your search to only Report
open access

Thin Oblique Airfoils at Supersonic Speed

Description: "The well-known methods of thin-airfoil theory have been extended to oblique or sweptback airfoils of finite aspect ratio moving at supersonic speeds. The cases considered thus far are symmetrical airfoils at zero lift having plan forms bounded by straight lines. Because of the conical form of the elementary flow fields, the results are comparable in simplicity to the results of the two-dimensional thin-airfoil theory for subsonic speeds" (p. 267).
Date: May 23, 1946
Creator: Jones, Robert T.
Item Type: Refine your search to only Report
open access

Investigations of Effects of Surface Temperature and Single Roughness Elements on Boundary-Layer Transition

Description: "The laminar boundary layer and the position of the transition point were investigated on a heated flat plate. It was found that the Reynolds number of transition decreased as the temperature of the plate is increased. It is shown from simple qualitative analytical considerations that the effect of variable viscosity in the boundary layer due to the temperature difference produces a velocity profile with an inflection point if the wall temperature is higher than the free-stream temperature" (p.… more
Date: August 28, 1946
Creator: Liepmann, Hans W. & Fila, Gertrude H.
Item Type: Refine your search to only Report
open access

A Thermodynamic Study of the Turbojet Engine

Description: "Charts are presented for computing thrust, fuel consumption, and other performance values of a turbojet engine for any given set of operating conditions and component efficiencies. The effects of pressure losses in the inlet duct and the combustion chamber, of variation in physical properties of the gas as it passes through the system, of reheating of the gas due to turbine losses, and of change in mass flow by the addition of fuel are included. The principle performance chart shows the effect… more
Date: June 1, 1946
Creator: Pinkel, Benjamin & Karp, Irving M.
Item Type: Refine your search to only Report
open access

Summary of Drag Characteristics of Practical-Construction Wing Sections

Description: "The effect of several parameters on the drag characteristics of practical-construction wing sections have been considered and evaluated. The effects considered were those of surface roughness, surface waviness, compressive load, and de-icers. The data were obtained from a number of tests in the Langley two-dimensional low-turbulence tunnels" (p. 359).
Date: July 11, 1946
Creator: Quinn, John H., Jr.
Item Type: Refine your search to only Report
open access

The Effects of Aerodynamic Heating and Heat Transfer on the Surface Temperature of a Body of Revolution in Steady Supersonic Flight

Description: "An approximate method for determining the convective cooling requirement in the laminar boundary-layer region of a body of revolution in high-speed flight was developed and applied to an example body. The cooling requirement for the example body was determined as a function of Mach number, altitude, size, and a surface-temperature parameter. The maximum value of Mach number considered was 3.0 and the altitudes considered were those within the lower constant-temperature region of the atmosphere… more
Date: October 14, 1946
Creator: Scherrer, Richard
Item Type: Refine your search to only Report
open access

Application of the Analogy Between Water Flow With a Free Surface and Two-Dimensional Compressible Gas Flow

Description: "The theory of the hydraulic analogy -- that is, the analogy between water flow with a free surface and two-dimensional compressible gas flow -- and the limitations and conditions of the analogy are discussed. A test was run using the hydraulic analogy as applied to the flow about circular cylinders of various diameters at subsonic velocities extending into the supercritical range. The apparatus and techniques used in this application are described and criticized" (p. 311).
Date: August 21, 1946
Creator: Orlin, W. James; Lindner, Norman J. & Bitterly, Jack G.
Item Type: Refine your search to only Report
open access

Analysis of Jet-Propulsion-Engine Combustion-Chamber Pressure Losses

Description: From Summary: "The development and the use of a chart for estimating the pressure losses in jet-engine combustion chambers are described. By means of the chart, the pressure losses due to fluid friction and to momentum changes in the air flow accompanying combustion can be separately evaluated. The over-all pressure losses computed from the pressure-loss chart are within 7 percent of the experimental values for the three types of combustion chambers considered herein."
Date: July 31, 1946
Creator: Pinkel, I. Irving & Shames, Harold
Item Type: Refine your search to only Report
open access

Quantitative Treatment of the Creep of Metals by Dislocation and Rate-Process Theories

Description: "An equation for the steady-state rate of creep has been derived by applying the theory of dislocations to the creep of pure metals. The form of this equation is in agreement with empirical equations describing creep rates. The theory was also used to predict the dependence of steady-state rate of creep on physical constants of the material and good agreement was obtained with data in the literature for pure annealed metals" (p. 169).
Date: January 1, 1946
Creator: Nowick, A. S. & Machlin, E. S.
Item Type: Refine your search to only Report
open access

The Lagrangian Multiplier Method of Finding Upper and Lower Limits to Critical Stresses of Clamped Plates

Description: "The theory of Lagrangian multipliers is applied to the problem of finding both upper and lower limits to the true compressive buckling stress of a clamped rectangular plate. The upper and lower limits thus bracket the true stress, which cannot be exactly found by the differential-equation approach. The procedure for obtaining the upper limit, which is believed to be new, presents certain advantages over the classical Rayleigh-Ritz method of finding upper limits" (p. 213).
Date: May 3, 1946
Creator: Budiansky, Bernard & Hu, Pai C.
Item Type: Refine your search to only Report
open access

The effect of wall interference upon the aerodynamic characteristics of an airfoil spanning a closed-throat circular wind tunnel

Description: "The results of a theoretical and experimental investigation of wall interference for an airfoil spanning a closed-throat circular wind tunnel are presented. Analytical equations are derived which relate the characteristics of an airfoil in the tunnel at subsonic speeds with the characteristics in free air. The analysis takes into consideration the effect of fluid compressibility and is based upon the assumption that the chord of the airfoil is small as compared with the diameter of the tunnel"… more
Date: 1946
Creator: Vincenti, Walter G. & Graham, Donald J.
Item Type: Refine your search to only Report
open access

Flight Investigation at High Speeds of the Drag of Three Airfoils and a Circular Cylinder Representing Full-Scale Propeller Shanks

Description: "Tests have been made at high speeds to determine the drag of models, simulating propeller shanks, in the form of a circular cylinder and three airfoils, the NACA 16-025, the NACA 16-040, and the NACA 16-040 with the rear 25 percent chord cut off. All the models had a maximum thickness of 4 1/2 inches to conform with average propeller-shank dimensions and a span of 20 1/4 inches. For the tests the models were supported perpendicular to the lower surface of the wing of an XP-51 airplane (p. 277). more
Date: June 7, 1946
Creator: Barlow, William H.
Item Type: Refine your search to only Report
open access

Cylinder-Temperature Correlation of a Single-Cylinder Liquid-Cooled Engine

Description: "An analysis based on nonboiling forced-convection heat-transfer theory is made of the cooling processes in liquid-cooled engine cylinders. Semiempirical equations that relate the average head and barrel temperatures with the primary engine and coolant parameters are derived. A correlation method based on these equations is applied to data obtained from previously reported investigations, which were conducted over large ranges of engine and coolant conditions with two liquid-cooled cylinders us… more
Date: October 1, 1946
Creator: Pinkel, Benjamin; Manganiello, Eugene J. & Bernardo, Everett
Item Type: Refine your search to only Report
open access

Compressibility Effects on the Longitudinal Stability and Control of a Pursuit-Type Airplane as Measured in Flight

Description: Measurements of the longitudinal stability and control of a pursuit-type airplane were made in flight up to a Mach number of 0.78. The data are presented in the form of curves showing the variation, with center-of-gravity position, dynamic pressure, and Mach number, of the stick-fixed and stick-free stability, control, and balance of the airplane.
Date: 1946
Creator: Turner, William N.; Steffen, Paul J. & Clousing, Lawrence A.
Item Type: Refine your search to only Report
open access

Analysis of spark-ignition engine knock as seen in photographs taken at 200,000 frames per second

Description: Report discussing a motion picture of the development of knock in a spark-ignition engine, which consists of 20 photographs taken at intervals of 5 microseconds, or at a rate of 200,000 photographs per second, with an equivalent wide-open exposure time of 6.4 microseconds for each photograph.
Date: 1946~
Creator: Miller, Cearcy D.; Olsen, H. Lowell; Logan, Walter O., Jr. & Osterstrom, Gordon E.
Item Type: Refine your search to only Report
open access

Measurements in Flight of the Pressure Distribution on the Right Wing of a Pursuit-Type Airplane at Several Values of Mach Number

Description: "Pressure-distribution measurements were made on the right wing of a pursuit-type airplane at values of Mach number up to 0.80. The results showed that a considerable portion of the lift was carried by components of the airplane other than the wings, and that the proportion of lift carried by the wings may vary considerably with Mach number, thus changing the bending moment at the wing root whether or not there is a shift in the lateral position of the center of pressure. It was also shown that… more
Date: 1946
Creator: Clousing, Lawrence A.; Turner, William N. & Rolls, L. Stewart
Item Type: Refine your search to only Report
open access

Analysis of cooling limitations and effect of engine-cooling improvements on level-flight cruising performance of four-engine heavy bomber

Description: From Introduction: "The difficulties experienced in cooling the exhaust-valve seats of the rear-row cylinders have been overcome to a considerable extent by improving the mixture distribution through application of the injection impeller (reference 1) and by augmenting the flow of cooling air to the critical baffles (reference 2). Flight tests of this airplane (reference 3) indicated that the temperatures of exhaust-valve seats on rear-row cylinders were markedly lowered by these modifications … more
Date: March 14, 1946
Creator: Marble, Frank E.; Miller, Marlon A. & Bell, E. Barton
Item Type: Refine your search to only Report
open access

Experimental and theoretical studies of surging in continuous-flow compressors

Description: Experiments have been conducted to determine the conditions that cause surging in compressors and to determine the effect of various installations and operating conditions on the character of the velocity and pressure variations occurring during surging. These investigations were made on three compressor units and the variation of static, total, and velocity pressure with time was recorded. In addition to the experimental studies, a simplified analysis was made to determine how instability of f… more
Date: 1946
Creator: Bullock, Robert O.; Wilcox, Ward W. & Moses, Jason J.
Item Type: Refine your search to only Report
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