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Airspeed Fluctuations as a Measure of Atmospheric Turbulence

Description: "Increments in structural loads due to atmospheric turbulence can be accurately expressed in terms of flight speed and effective gust velocities (reference 4). Data from which the effective gust velocities could be computed were also obtained during the flights of the XC-35 airplane. These data have been used to determine the significance of the fluctuations in the pilot's indicated-airspeed readings in relation to structural loads to due to atmospheric turbulence" (p. 3).
Date: July 1945
Creator: Tolefson, H. B.
Partner: UNT Libraries Government Documents Department
open access

An analysis of life expectancy of airplane wings in normal cruising flight

Description: From Summary: "The independent variables considered in the analysis included stress-concentration factor, stress-load relation, wing loading, design and cruising speeds, design gust velocity, and airplane size. Several methods for estimating fatigue life from gust frequencies are discussed."
Date: July 1945
Creator: Putnam, Abbott A.
Partner: UNT Libraries Government Documents Department
open access

Application of a numerical procedure to stress analysis of stringer-reinforced panels

Description: From Introduction: "In the present paper a numerical procedure for the stress analysis of flat-sheet and stringer combinations of arbitrary construction and loading is presented and applied to axially loaded panels and to the reinforced covers of box beams."
Date: March 1945
Creator: Kempner, Joseph
Partner: UNT Libraries Government Documents Department
open access

The application of data on strength under repeated stresses to the design of aircraft

Description: From Summary: "This report suggests a method whereby information on the strength under repeated stresses of aircraft materials or structural parts can be used in conjunction with information on service loadings as a means of comparing alternative designs."
Date: October 1945
Creator: Jackson, L. R.
Partner: UNT Libraries Government Documents Department
open access

Bending and Shear Stresses Developed by the Instantaneous Arrest of the Root of a Cantilever Beam Rotating With Constant Angular Velocity About a Transverse Axis Through the Root

Description: From Summary: "A theoretical investigation was made of the behavior of a cantilever beam in rotational motion about a transverse axis through the root determining the stresses, the deflections, and the accelerations that occur in the beam as a result of the arrest of motion. The equations for bending and shear stress reveal that, at a given percentage of the distance from root to tip and at a given trip velocity, the bending stresses for a particular mode are independent of the length of the be… more
Date: June 1945
Creator: Stowell, Elbridge Z.; Schwartz, Edward B. & Houbolt, John C.
Partner: UNT Libraries Government Documents Department
open access

Calculations of Economy of 18-Cylinder Radial Aircraft Engine With Exhaust-Gas Turbine Geared to the Crankshaft at Cruising Speed

Description: Report presenting calculations based on dynamometer test-stand data on an 18-cylinder radial engine made to determine the improvement in fuel consumption that can be obtained by gearing an exhaust-gas turbine to the engine crankshaft in order to increase the engine shaft work.
Date: December 1945
Creator: Hannum, Richard W.
Partner: UNT Libraries Government Documents Department
open access

Calculations of the Performance of a Compression-Ignition Engine-Compressor Turbine Combination 1: Performance of a Highly Supercharged Compression-Ignition Engine

Description: From Summary: "Small high-speed single-cylinder compression-ignition engines were tested to determine their performance characteristics under high supercharging. Calculations were made on the energy available in the exhaust gas of the compression-ignition engines. The maximum power at any given maximum cylinder pressure was obtained when the compression pressure was equal to the maximum cylinder pressure. Constant-pressure combustion was found possible at an engine speed of 2200 rpm."
Date: December 1945
Creator: Sanders, J. C. & Mendelson, Alexander
Partner: UNT Libraries Government Documents Department
open access

Charts for Determining Jet-Boundary Corrections for Complete Models in 7- by 10-Foot Closed Rectangular Wind Tunnels

Description: Report presenting calculations of numerical values of the jet-boundary corrections to the angle of attack and the induced-drag, rolling-moment, and yawing-moment coefficients for complete airplane or wing models in 7- by 10-foot closed rectangular wind tunnels. The results showed that the wing area was the most important variable, as has usually been assumed in previous calculations. When the corrections were based on wing area, the effect of most of the other variables was negligible.
Date: September 1945
Creator: Gillis, Clarence L.; Polhamus, Edward C. & Gray, Joseph L., Jr.
Partner: UNT Libraries Government Documents Department
open access

Charts for the Minimum-Weight Design of 24S-T Aluminum-Alloy Flat Compression Panels With Longitudinal Z-Section Stiffeners

Description: Report presenting design charts for 24S-T aluminum-alloy flat compression panels with longitudinal Z-section stiffeners. It was found that maximum possible structural efficiency with these panels requires closer stiffener spacings than those now in common use.
Date: August 1945
Creator: Schuette, Evan H.
Partner: UNT Libraries Government Documents Department
open access

Charts of Pressure, Density, and Temperature Changes at an Abrupt Increase in Cross-Sectional Area of Flow of Compressible Air

Description: "Equations have been derived for the change in the quantities that define the thermodynamic state of air - pressure, density, and temperature - at an abrupt increase in cross-sectional area of flow of compressible air. Results calculated from these equations are given in a table and are plotted as curves showing the variation of the calculated qualities with the area expansion ratio in terms of the initial Mach number as parameter. Only the subsonic region of flow is considered" (p. 1).
Date: January 1945
Creator: Joyner, Upshur T.
Partner: UNT Libraries Government Documents Department
open access

Column and plate compressive strengths of aircraft structural materials: 17S-T aluminum-alloy sheet

Description: From Summary: "Column and plate compressive strengths of 17S-T aluminum-alloy sheet were determined both within and beyond the elastic range from tests of thin-strip columns and from local-instability tests of formed Z- and channel-section columns. These tests are part of an extensive research investigation to provide data on the structural strengths of various aircraft materials. Results are presented in the form of curves and charts that may be used in the design and analysis of aircraft stru… more
Date: June 1945
Creator: Heimerl, George J. & Roy, J. Albert
Partner: UNT Libraries Government Documents Department
open access

Column and Plate Compressive Strengths of Aircraft Structural Materials: 24S-T Aluminum-Alloy Sheet

Description: "Column and plate compressive strengths of 24S-T aluminum-alloy sheet were determined both within and beyond the elastic range from tests of thin-strip columns and from local-instability tests of formed Z-end channel-section columns. These tests are the first of a series in an extensive research investigation to provide data on the structural strength of various aircraft materials. The results, which are presented in the form of curves and charts that may be used in the design and analysis of a… more
Date: June 1945
Creator: Lundquist, Eugene E.; Schuette, Evan H.; Heimerl, George J. & Roy, J. Albert
Partner: UNT Libraries Government Documents Department
open access

Column and plate compressive strengths of aircraft structural materials: extruded 24S-T aluminum alloy

Description: Report presenting column and plate compressive strengths of extruded 24S-T aluminum alloy determined both within and beyond the elastic range from tests of thin-strip columns and local-instability tests of H-, Z-, and channel-section columns. The tests are part of a research investigation to provide data on the structural strength of various aircraft materials. Results regarding compressive stress-strain curves and column and plate compressive strengths are provided.
Date: July 1945
Creator: Heimerl, George J. & Roy, J. Albert
Partner: UNT Libraries Government Documents Department
open access

Column and Plate Compressive Strengths of Aircraft Structural Materials: Extruded 24S-T Aluminum Alloy

Description: Column and plate compressive strengths of extruded 24S-T aluminum alloy were determined both within and beyond the elastic range from tests of thin-strip columns and local-instability tests of H-, Z-,and channel-section columns. These tests are part of an extensive research investigation to provide data on the' structural strength of various aircraft materials. The results are presented in the form of curves and charts that are suitable for use in the design and analysis of aircraft structures.
Date: July 1945
Creator: Heimerl, George J. & Roy, J. Albert
Partner: UNT Libraries Government Documents Department
open access

Column and plate compressive strengths of aircraft structural materials: extruded 75S-T aluminum alloy

Description: Report presenting column and plate compressive strengths of extruded 75S-T aluminum alloy both within and beyond the elastic range from tests of thin-strip columns and local-instability tests of H-, Z-, and channel-section columns. The tests are part of an extensive research investigation to provide data on the structural strength of various aircraft materials. Results regarding compressive stress-strain curves and column and plate compressive strengths are provided.
Date: July 1945
Creator: Heimerl, George J. & Roy, J. Albert
Partner: UNT Libraries Government Documents Department
open access

Column and Plate Compressive Strengths of Aircraft Structural Materials: Extruded R303-T Aluminum Alloy

Description: "Column and plate compressive strengths of extruded R303-T aluminum alloy were determined both within and beyond the elastic range form tests of thin-strip columns and local-instability tests of H-, Z-, and channel-section columns. These tests are part of an extensive research investigation to provide data on the structural strength of various aircraft materials. The results are presented in the form of curves and charts that are suitable for use in the design and analysis of aircraft structure… more
Date: October 1945
Creator: Heimerl, George J. & Fay, Douglas P.
Partner: UNT Libraries Government Documents Department
open access

Comparison between calculated and measured loads on wing and horizontal tail in pull-up maneuvers

Description: Report presenting comparisons of measured and calculated loads on the wing and horizontal tail in pull-up maneuvers for six airplanes over a range of weights. Good agreement was obtained between calculated and measured loads under certain circumstances, but the agreement in some cases was only fair, which may be attributed to poor quantitative knowledge of the aerodynamic parameters or to violation of the assumptions on which the method is based.
Date: October 1945
Creator: Matheny, Cloyce E.
Partner: UNT Libraries Government Documents Department
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A comparison of analytically and experimentally determined isothermal pressure losses in a heat-exchanger installation

Description: The results of this analysis indicate that isothermal pressure losses can be predicted analytically in the type of ducting system which may be broken down into the elementary forms of elbows, diffusers, and straight ducts for which pressure-loss data are published.
Date: May 1945
Creator: Hillendahl, Wesley H.
Partner: UNT Libraries Government Documents Department
open access

A Comparison of Two Flight-Test Procedures for the Determination of Aileron Control Capabilities of an Airplane

Description: Report presenting a comparison of two flight-test procedures for the determination of the aileron control capabilities of an airplane. The procedures consist of performing rudder-fixed aileron rolls from straight unbanked flight and from steady turning flight. Results regarding rate of roll comparison and sideslip-angle comparison are provided.
Date: July 1945
Creator: Skoog, Richard B.
Partner: UNT Libraries Government Documents Department
open access

Comparisons of Methods of Computing Bending Moments in Helicopter Rotor Blades in the Plane of Flapping

Description: Report presenting several methods of computing bending moments in helicopter rotor blades in the plane of flapping, and the results of a numerical example analyzed by four different methods are compared. The effect of computed bending moments of the tip-loss correction introduced by Wheatley is also considered.
Date: August 1945
Creator: Duberg, John E. & Luecker, Arthur R.
Partner: UNT Libraries Government Documents Department
open access

A Cooling Correlation of the Wright R-2600-8 Engine Showing the Effect of Water as an Internal Coolant

Description: Report presenting an attempt to establish a correlation of the cooling characteristics of the Wright R-2600-8 engine with water as an internal coolant and to investigate methods of introducing the water. A cooling correlation, including the effect of water as an internal coolant, was established by use of the NACA cooling-correlation method. Results regarding the cooling-performance predictions and engine condition are provided.
Date: February 1945
Creator: Koenig, Robert J. & Engelman, Helmuth W.
Partner: UNT Libraries Government Documents Department
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Correlation of exhaust-valve temperatures with engine operating conditions and valve design

Description: Report presenting a theory regarding engine-cooling variables from a previous report, which was used as a basis for the development of a semi-empirical equation to correlate exhaust-valve temperature with engine conditions. Results regarding the determination of constants, influences of operating variables on mean effective gas temperatures, thermal-resistance factor, and accuracy of correlating equation are provided.
Date: October 1945
Creator: Zipkin, M. A. & Sanders, J. C.
Partner: UNT Libraries Government Documents Department
open access

Critical combinations of shear and transverse direct stress for an infinitely long flat plate with edges elastically restrained against rotation

Description: Report presenting an exact solution and a closely concurring approximate energy solution for the buckling of an infinitely long flat plate under combined shear and transverse direct stress with edges elastically restrained against rotation. An appreciable fraction of the critical stress in pure shear may be applied to the plate without any reduction in the transverse compressive stress necessary to produce buckling.
Date: January 1945
Creator: Batdorf, S. B. & Houbolt, John C.
Partner: UNT Libraries Government Documents Department
open access

Cylinder Temperatures of Two Liquid-Cooled Aircraft Cylinders for Various Engine and Coolant Conditions

Description: Report presenting tests conducted with two liquid-cooled cylinders in order to isolate the effects of the various engine and coolant variables on cylinder temperatures and to obtain engine-cooling data required for a fundamental study of the heat-transfer processes in liquid-cooled engines. Cylinder temperatures were obtained for a large range of engine speeds, manifold pressures, carburetor-air temperatures, fuel-air ratios, spark advances, coolant-flow rates, average coolant temperatures, and… more
Date: October 1945
Creator: Manganiello, Eugene J. & Bernardo, Everett
Partner: UNT Libraries Government Documents Department
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