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  Partner: UNT Libraries Government Documents Department
 Decade: 1930-1939
 Year: 1939
 Collection: Technical Report Archive and Image Library
Acceleration, stress, and deflection measurements on the XB-15 bomber in gusty air

Acceleration, stress, and deflection measurements on the XB-15 bomber in gusty air

Date: June 1, 1939
Creator: Pearson, Henry A
Description: None
Contributing Partner: UNT Libraries Government Documents Department
Activation of hydrocarbons and the octane number

Activation of hydrocarbons and the octane number

Date: October 1, 1939
Creator: Peschard, Marcel
Description: This report presents an examination of the history of research on engine knocking and the various types of fuels used in the investigations of this phenomenon. According to this report, the spontaneous ignition of hydrocarbons doped with oxygen follows the logarithmic law within a certain temperature range, but not above 920 degrees K. Having extended the scope of investigations to prove hydrocarbons, the curves of the mixtures burned by air should then be established by progressive replacement of pure iso-octane with heptane. Pentane was also examined in this report.
Contributing Partner: UNT Libraries Government Documents Department
Adhesion of ice in its relation to the de-icing of airplanes

Adhesion of ice in its relation to the de-icing of airplanes

Date: August 1, 1939
Creator: Rothrick, A M
Description: The various possible means of preventing ice adhesion on airplane surfaces are critically reviewed. Results are presented of tests of the adhesives forces between ice and various solid and liquid forces. It is concluded that the de-icing of airplane wings by heat from engine exhaust shows sufficient promise to warrant full-scale tests. For propellers, at least, and possibly for certain small areas such as windshields, radio masts, etc. the use of de-icing or adhesion-preventing liquids will provide the best means of protection.
Contributing Partner: UNT Libraries Government Documents Department
Aerodynamic characteristics of a 4-engine monoplane showing comparison of air-cooled and liquid-cooled engine installations

Aerodynamic characteristics of a 4-engine monoplane showing comparison of air-cooled and liquid-cooled engine installations

Date: July 1, 1939
Creator: Wilson, Herbert A , Jr & Silverstein, Abe
Description: None
Contributing Partner: UNT Libraries Government Documents Department
The aerodynamic characteristics of six full-scale propellers having different airfoil sections

The aerodynamic characteristics of six full-scale propellers having different airfoil sections

Date: January 1, 1939
Creator: Biermann, David
Description: Wind-tunnel tests are reported of six 3-blade 10-foot propellers operated in front of a liquid-cooled engine nacelle. The propellers were identical except for blade airfoil sections, which were: Clark y, R.A.F. 6, NACA 4400, NACA 2400-34, NACA 2rsub200, and NACA 6400. The range of blade angles investigated extended for 15 degrees to 40 degrees for all propellers except the Clark y, for which it extended to 45 degrees. The results showed that the range in maximum efficiency between the highest and lowest values was about 3 percent. The highest efficiencies were for the low-camber sections.
Contributing Partner: UNT Libraries Government Documents Department
Air flow in the boundary layer of an elliptic cylinder

Air flow in the boundary layer of an elliptic cylinder

Date: January 1, 1939
Creator: Schubauer, G B
Description: The boundary layer of an elliptic cylinder of major and minor axis 11.78 and 3.98 inches, respectively, was investigated in air stream in which the turbulence could be varied. Conditions were arranged so that the flow was two-dimensional with the major axis of the ellipse parallel to the undisturbed stream. Speed distributions across the boundary layer were determined with a hot-wire anemometer at a number of positions about the surface for the lowest and highest intensities of turbulence, with the air speed in both cases sufficiently high to produce a turbulent boundary layer over the downstream part of the surface. The magnitude and the frequency of the speed fluctuations in the boundary layer were also measured by the use of the conventional type of hot-wire turbulence apparatus. Stream turbulence was found to affect both the nature of transition from laminar to turbulent flow in the layer and the position on the surface at which transition occurred. Transition was then investigated in detail with stream turbulence of several different scales and intensities.
Contributing Partner: UNT Libraries Government Documents Department
Aircraft rate-of-climb indicators

Aircraft rate-of-climb indicators

Date: January 1, 1939
Creator: Johnson, Daniel P
Description: The theory of the rate-of-climb indicator is developed in a form adapted for application to the instrument in its present-day form. Compensations for altitude, temperature, and rate of change of temperature are discussed from the designer's standpoint on the basis of this theory. Certain dynamic effects, including instrument lag, and the use of the rate-of-climb indicator as a statoscope are also considered. Modern instruments are described. A laboratory test procedure is outlined and test results are given.
Contributing Partner: UNT Libraries Government Documents Department
Airfoil section data obtained in the NACA variable-density tunnel as affected by support interference and other corrections

Airfoil section data obtained in the NACA variable-density tunnel as affected by support interference and other corrections

Date: January 1, 1939
Creator: Jacobs, Eastman N
Description: The results of an investigation of the effect of support interference on airfoil drag data obtained in the variable-density tunnel are presented. As a result of the support interference, previously published airfoil data from the variable-density tunnel have shown too large drag coefficients and too large a rate of increase of drag coefficients and too large a rate increase of drag coefficients with airfoil thickness. The practical effect of the corrections on the choice of the optimum section is briefly considered and corrected data for a selected list of airfoils are presented as a convenience to the designer. Methods of correcting published data for other airfoils are presented.
Contributing Partner: UNT Libraries Government Documents Department
Airfoil Theory at Supersonic Speed

Airfoil Theory at Supersonic Speed

Date: June 1, 1939
Creator: Schlichting, H
Description: A theory is developed for the airfoil of finite span at supersonic speed analogous to the Prandtl airfoil theory of 1918-1919 for incompressible flow. In addition to the profile and induced drags, account must be taken at supersonic flow of still another drag, namely, the wave drag, which is independent of the wing aspect ratio. Both wave and induced drags are proportional to the square of the lift and depend on the Mach number, that is, the ratio of flight to sound speed. In general, in the case of supersonic flow, the drag-lift ratio is considerably less favorable than is the case for incompressible flow. Among others the following examples are considered: 1) lifting line with constant lift distribution (horseshoe vortex); 2) computation of wave and induced drag and the twist of a trapezoidal wing of constant lift density; 3) computation of the lift distribution and drag of an untwisted rectangular wing.
Contributing Partner: UNT Libraries Government Documents Department
Annual report of the National Advisory Committee for Aeronautics (24th).administrative report including Technical Report nos. 612 to 644

Annual report of the National Advisory Committee for Aeronautics (24th).administrative report including Technical Report nos. 612 to 644

Date: January 1, 1939
Creator: unknown
Description: Report includes the National Advisory Committee for Aeronautics letter of submittal to the President, summaries of the committee's activities and research accomplished, bibliographies, and financial report.
Contributing Partner: UNT Libraries Government Documents Department
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