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Experiments With an Airfoil Model on Which the Boundary Layers Are Controlled Without the Use of Supplementary Equipment

Description: This report describes test made in the Variable Density Wind Tunnel of the NACA to determine the possibility of controlling the boundary layer on the upper surface of an airfoil by use of the low pressure existing near the leading edge. The low pressure was used to induce flow through slots in the upper surface of the wing. The tests showed that the angle of attack for maximum lift was increased at the expense of a reduction in the maximum lift coefficient and an increase in the drag coefficien… more
Date: April 1931
Creator: Abbott, Ira H.
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Fuselage-drag tests in the variable-density wind tunnel: streamline bodies of revolution, fineness ratio of 5

Description: From Summary: "Results are presented of the drag tests of six bodies of revolution with systematically varying shapes and with a fineness ratio of 5. The forms were derived from source-sink distributions, and formulas are presented for the calculation of the pressure distribution of the forms. The tests were made in the N.A.C.A. variable-density tunnel over a range of values of Reynolds number from about 1,500,000 to 25,000,000. The results show that the bodies with the sharper noses and tails … more
Date: September 1937
Creator: Abbott, Ira H.
open access

Flow observations with tufts and lampblack of the stalling of four typical airfoil sections in the NACA variable-density tunnel

Description: From Summary: "A preliminary investigation of the stalling processes of four typical airfoil sections was made over the critical range of the Reynolds Number. Motion pictures were taken of the movements of small silk tufts on the airfoil surface as the angle of attack increased through a range of angles including the stall. The boundary-layer flow also at certain angles of attack was indicated by the patterns formed by a suspension of lampblack in oil brushed onto the airfoil surface. These obs… more
Date: October 1938
Creator: Abbott, Ira H. & Sherman, Albert
open access

Theoretical study of the lateral frequency response to gusts of a fighter airplane, both with controls fixed and with several types of autopilots

Description: Report presenting a theoretical approach to determine the lateral frequency response of a fighter airplane to side gusts and rolling gusts at a Mach number of 0.7 and an altitude of 30,000 feet. Frequency response and power spectral density were determined with the controls fixed and in combination with three different basic types of attitude autopilots.
Date: March 1956
Creator: Adams, James J. & Mathews, Charles W.
open access

Determination of Shapes of Boattail Bodies of Revolution for Minimum Wave Drag

Description: "By use of an approximate equation for the wave drag of slender bodies of revolution in a supersonic flow field, the optimum shapes of certain boattail bodies are determined for minimum wave drag. The properties of three specific families of bodies are determined, the first family consisting of bodies having a given length and base area and a contour passing through a prescribed point between the nose and base, the second family having fixed length, base area, and maximum area, and the third fa… more
Date: August 21, 1951
Creator: Adams, Mac C.
open access

Flight Investigation of the Effect of a Local Change in Wing Contour on Chordwise Pressure Distribution at High Speeds

Description: Report presenting testing in high-speed flight with a fighter airplane to determine the effect of chordwise pressure distribution resulting from a minor modification in the contour of the wing upper surface. A faired bulge was added to the contour and chordwise pressure distributions were obtained on the original and modified contours.
Date: September 1946
Creator: Adams, Richard E. & Silsby, Norman S.
open access

Analysis of horizontal-tail loads in pitching maneuvers on a flexible swept-wing jet bomber

Description: From Introduction: "The analysis of flight data in the present report is, to a large extent, based on analyses and information contained in references 1 and 2 for wing deflections, reference 3 for horizontal-tail parameters, reference 4 for airplane lift-curve slopes and angles of zero lift, and reference 5 for wing centers of pressure."
Date: December 1957
Creator: Aiken, William S., Jr.
open access

Flight determination of wing and tail loads on a fighter-type airplane by means of strain-gage measurements

Description: Report presenting a flight investigation to determine the contributions of wing, tail, and fuselage to the total airplane lift of a propeller-driven fighter-type airplane. The tests occurred over a range of Mach numbers. The loads on the various airplane components were measured by the use of calibrated strain-gage installations located at the roots of the wings and horizontal tail surfaces.
Date: October 1948
Creator: Aiken, William S., Jr.
open access

Standard Nomenclature for Airspeeds With Tables and Charts for Use in Calculation of Airspeed

Description: Note presenting symbols and definitions of various airspeed terms that have been adopted as standard by the NACA Subcommittee on Aircraft Structural Design. the equations, charts, and tables required in the evaluation of true airspeed, calibrated airspeed, equivalent airspeed, impact and dynamic pressures, and Mach and Reynolds numbers have been compiled.
Date: September 1946
Creator: Aiken, William S., Jr.
open access

A Comparison of Wing Loads Measured in Flight on a Fighter-Type Airplane by Strain-Gage and Pressure Distribution Methods

Description: Note presenting pressure distribution measurements made on the wing of a fighter-type airplane to determine the span loading and to compare center-of-pressure results with those obtained by strain-gage measurements on the same airplane during a previous flight investigation. Flight tests were all made at a pressure altitude of about 30,000 feet and covered a Mach number range from approximately 0.35 to 0.81. Results regarding additional air load, spanwise center of pressure of additional air lo… more
Date: November 1949
Creator: Aiken, William S., Jr. & Howard, Donald A.
open access

Analysis of the Horizontal-Tail Loads Measured in Flight on a Multiengine Jet Bomber

Description: "The primary objectives of the present paper are to report the horizontal-tail-loads measurements for configuration B which have not previously been reported and to summarize the horizontal-tail-loads results obtained with both configurations. The manner in which the aerodynamic-loads data were analyzed to include structural temperature effects and fuselage flexibility effects constitutes an important part of the present paper" (p. 1).
Date: September 1955
Creator: Aiken, William S., Jr. & Wiener, Bernard
open access

Extension of Pack Method for Compressive Tests

Description: "The pack method for determining compressive stress-strain graphs described in NACA Report No. 649 has been modified to extend it's application to thinner gages and stronger materials. The principal modifications consisted in the provision of additional support against instability cementing the specimens of the pack together with fused shellac and the provision of special clamps to hold the specimens together while the test is in progress. The shellac was found to increase the buckling load of … more
Date: December 1940
Creator: Aitchison, C. S.
open access

A Subpress for Compressive Tests

Description: "A subpress for compressive tests is described. The subpress was designed primarily for use in developing and investigating methods for testing thin sheet metal in compression. Provision was made for testing fixed-end and flat-end specimens with or without various types of lateral support against buckling. Compressive stress-strain data for a sheet of 0.032-inch 24S-RT aluminum alloy were obtained with the subpress by the pack method and by the single-thickness method" (p. 1).
Date: December 1943
Creator: Aitchison, C. S. & Miller, James A.
open access

Tensile and Compressive Tests of Magnesium Alloy J-1 Sheet

Description: Note presenting tensile and compressive stress-strain curves, stress-deviation curves, and secant modulus-stress curves for longitudinal and transverse specimens of magnesium alloy J-1 sheets 0.032 and 0.102 inch thick. Significant differences were found between the tensile and compressive stress-strain curves and between the compressive stress-strain curves for the longitudinal and transverse questions.
Date: December 1943
Creator: Aitchison, C. S. & Miller, James A.
open access

Analytical Method for Determining Transmission and Absorption of Time-Dependent Radiation Through Thick Absorbers 3: Absorber With Radioactive Daughter Products

Description: Report presenting a theoretical treatment of absorption problems that considers the following cases: radiation is normal to an absorber with plane parallel surfaces, radiations are of several polyenergetic types, induced radioactive isotopes decay to stable atoms in multistep decay processes, and radiations from the absorber affect the time-dependency of the source activity. Radiation from intermediate isotopes can become more dangerous than the original activity, so the entire range of radiati… more
Date: June 1950
Creator: Allen, G.
open access

Tables for Determining Reduction of Energy and Intensity of X-Rays and Gamma-Rays at Various Scattering Angles in Small Thickness of Matter

Description: Report presenting tables for determining the total-absorption coefficients as well was the intensities and spectral distribution of gamma rays at any scattering angle. Both experimental and computed data on gamma rays of quantum energies up to 20 million electron volts for all elements which have significant data available are provided. The accuracy of results is obtained by the use of tables.
Date: February 1950
Creator: Allen, G.
open access

Friction and wear with reactive gases at temperatures up to 1200 degrees F

Description: Report presenting friction and wear experiments conducted to explore the effects of high temperature, varied chlorine content, sulfur catalysis, and preformation of sulfide films on boundary lubrication with reactive gases. Results regarding sulfur hexafluoride, dichlorodifluoromethane, chlorotrifluoromethane, chlorotrifluorometahne plus sulfur hexafluoride, and dichlorodifluoromethane plus sulfur hexafluoride are provided.
Date: September 1958
Creator: Allen, Gordon P.; Buckley, Donald H. & Johnson, Robert L.
open access

Motion of a ballistic missile angularly misaligned with the flight path upon entering the atmosphere and its effect upon aerodynamic heating, aerodynamic loads, and miss distance

Description: From Summary: "An analysis is given of the oscillating motion of a ballistic missile which upon entering the atmosphere is angularly misaligned with respect to the flight path. The history of the motion for some example missiles is discussed from the point of view of the effect of the motion on the aerodynamic heating and loading. The miss distance at the target due to misalignment and to small accidental trim angles is treated. The stability problem is also discussed for the case where the mis… more
Date: October 1957
Creator: Allen, H. Julian
open access

A simplified method for the calculation of airfoil pressure distribution

Description: From Summary: "A method is presented for the rapid calculation of the pressure distribution over an airfoil section when the normal-force distribution and the pressure distribution over the "base profile" (i.e., the profile of the same airfoil were the camber line straight and the resulting airfoil at zero angle of attack) are known. This note is intended as a supplement to N.A.C.A. Report Nos. 631 and 634 wherein methods are presented for the calculation of the normal-force distribution over p… more
Date: May 1939
Creator: Allen, H. Julian
open access

A Study of the Motion and Aerodynamic Heating of Missiles Entering the Earth's Atmosphere at High Supersonic Speeds

Description: A simplified analysis of the velocity and deceleration history of missiles entering the earth's atmosphere at high supersonic speeds is presented. The results of this motion analysis are employed to indicate means available to the designer for minimizing aerodynamic heating. The heating problem considered involves not only the total heat transferred to a missile by convection, but also the maximum average and local time rates of convective heat transfer.
Date: October 1957
Creator: Allen, H. Julian & Eggers, A. J., Jr.
open access

The Effect of Compressibility on the Growth of the Laminar Boundary Layer on Low-Drag Wings and Bodies

Description: Report presenting a consideration of the development of the laminar boundary layer in a compressible fluid. Formulas are given for determining the boundary-layer thickness and the boundary-layer Reynolds number, which is a measure of the boundary-layer stability, for airfoils and bodies of revolution.
Date: July 1947
Creator: Allen, H. Julian & Nitzberg, Gerald E.
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