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Air flow around finned cylinders

Description: Report presents the results of a study made to determine the air-flow characteristics around finned cylinders. Air-flow distribution is given for a smooth cylinder, for a finned cylinder having several fin spacings and fin widths, and for a cylinder with several types of baffle with various entrance and exit shapes. The results of these tests show: that flow characteristics around a cylinder are not so critical to changes in fin width as they are to fin spacing; that the entrance of the baffle has a marked influence on its efficiency; that properly designed baffles increase the air flow over the rear of the cylinder; and that these tests check those of heat-transfer tests in the choice of the best baffle.
Date: November 7, 1935
Creator: Brevoort, M J & Rollin, Vern G
Item Type: Report
Partner: UNT Libraries Government Documents Department

Air flow in a separating laminar boundary layer

Description: The speed distribution in a laminar boundary layer on the surface of an elliptic cylinder, of major and minor axes 11.78 and 3.98 inches, respectively, has been determined by means of a hot-wire anemometer. The direction of the impinging air stream was parallel to the major axis. Special attention was given to the region of separation and to the exact location of the point of separation. An approximate method, developed by K. Pohlhausen for computing the speed distribution, the thickness of the layer, and the point of separation, is described in detail; and speed-distribution curves calculated by this method are presented for comparison with experiment.
Date: December 1, 1934
Creator: Schubauer, G. B.
Item Type: Report
Partner: UNT Libraries Government Documents Department

Air flow in the boundary layer near a plate

Description: The published data on the distribution of speed near a thin flat plate with sharp leading edge placed parallel to the flow (skin friction plate) are reviewed and the results of some additional measurements are described. The purpose of the experiments was to study the basic phenomena of boundary-layer flow under simple conditions.
Date: March 1936
Creator: Dryden, Hugh L.
Item Type: Report
Partner: UNT Libraries Government Documents Department

Air flow in the boundary layer of an elliptic cylinder

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.
Date: August 6, 1938
Creator: Schubauer, G B
Item Type: Report
Partner: UNT Libraries Government Documents Department

Air flow through poppet valves

Description: Report discusses the comparative continuous flow characteristics of single and double poppet valves. The experimental data presented affords a direct comparison of valves, single and in pairs of different sizes, tested in a cylinder designed in accordance with current practice in aviation engines.
Date: 1918
Creator: Lewis, G W & Nutting, E M
Item Type: Report
Partner: UNT Libraries Government Documents Department

Air force and moment for N-20 wing with certain cut-outs

Description: The airplane designer often finds it necessary, in meeting the requirements of visibility, to remove area or to otherwise locally distort the plan or section of an airplane wing. This report, prepared for the Bureau of Aeronautics January 15, 1925, contains the experimental results of tests on six 5 by 30 inch N-20 wing models, cut out or distorted in different ways, which were conducted in the 8 by 8 foot wind tunnel of the Navy Aerodynamical Laboratory in Washington in 1924. The measured and derived results are given without correction for vl/v for wall effect and for standard air density, p=0.00237 slug per cubic foot.
Date: November 29, 1926
Creator: Smith, R H
Item Type: Report
Partner: UNT Libraries Government Documents Department

Ice prevention on aircraft by means of engine exhaust heat and a technical study of heat transmission from a Clark y airfoil

Description: This investigation was conducted to study the practicability of employing heat as a means of preventing the formation of ice on airplane wings. The report relates essentially to technical problems regarding the extraction of heat from the exhaust gases and its proper distribution over the exposed surfaces. In this connection a separate study has been made to determine the variation of the coefficient of heat transmission along the chord of a Clark Y airfoil. Experiments on ice prevention both in the laboratory and in flight show conclusively that it is necessary to heat only the front portion of the wing surface to effect complete prevention. Experiments in flight show that a vapor-heating system which extracts heat from the exhaust and distributes it to the wings is an entirely practical and efficient method for preventing ice formation.
Date: January 1, 1933
Creator: Clay, William C & Theodorsen, Theodore
Item Type: Report
Partner: UNT Libraries Government Documents Department

Tests on duralumin columns for aircraft construction

Description: The following paper is based on the results of tests, upon duralumin columns, contained in two theses presented to the Department of Civil and Sanitary Engineering of the Massachusetts Institute of Technology.
Date: November 1, 1924
Creator: Lee, John G
Item Type: Report
Partner: UNT Libraries Government Documents Department

Airfoil Theory at Supersonic Speed

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.
Date: June 1939
Creator: Schlichting, H
Item Type: Report
Partner: UNT Libraries Government Documents Department

"AM" flexible metal joint

Description: A flexible metal joint used for connecting fuel lines is investigated and methods for assembly are included.
Date: February 1923
Item Type: Report
Partner: UNT Libraries Government Documents Department

"AM" gasoline cock.

Description: The "AM" cock was designed specially for gasoline pipes on vehicles using internal combustion engines (airplanes, airships, automobiles, tractors, battle "tanks", boats, etc.).
Date: February 1923
Item Type: Report
Partner: UNT Libraries Government Documents Department

Experimental investigation of the physical properties of medium and heavy oils, their vaporization and use in explosion engines. Part IV

Description: This report presents a theoretical treatment of the vaporization process of medium and heavy oils. The results of this investigation, which were mostly obtained from the lighter components of the heavy fuels, require a 10- or 16-fold vaporization in comparison with gasoline. We must attain a still finer degree of atomization, in order to include the heavier components.
Date: December 1926
Creator: Heinlein, Fritz
Item Type: Report
Partner: UNT Libraries Government Documents Department

Twelfth Rhon soaring contest, 1931

Description: The crew of the "Fafnir" was given an excellent opportunity for collecting first-hand data as to the usefulness of gliders in the Alps. It is necessary to recount the remarkable glider achievements ahead of the Rhon Soaring Contest, in order to understand the tension and expectation with which the Rhon contest was anticipated.
Date: May 1932
Creator: Georgii, Walter
Item Type: Report
Partner: UNT Libraries Government Documents Department

Magnan glider M-2

Description: The construction of the Magnan glider, M-2, is presented which is designed to fly in so-called horizontal winds.
Date: February 1924
Creator: Lesage, M Andre
Item Type: Report
Partner: UNT Libraries Government Documents Department

Aerial photography : obtaining a true perspective

Description: A demonstration was given within the last few days at the British Museum by Mr. J. W. Gordon, author of "Generalized Linear Perspective" (Constable and Co.), a work describing a newly-worked-out system by which photographs can be made available for the purpose of exactly recording the dimensions of the objects photographed even when the objects themselves are presented foreshortened in the photograph.
Date: April 1923
Item Type: Report
Partner: UNT Libraries Government Documents Department

Airplane drag

Description: It has been less well understood that the induced drag (or, better said, the undesired increase in the induced drag as compared with the theoretical minimum calculated by Prandtl) plays a decisive role in the process of taking off and therefore in the requisite engine power. This paper seeks to clarify the induced drag.
Date: December 1929
Creator: Topfer, Carl
Item Type: Report
Partner: UNT Libraries Government Documents Department

Airplane flight in the stratosphere

Description: This brief survey of the problems encountered in high-altitude flight deals in particular with the need for high lift coefficient in the wings, large aspect ratios in the wings, and also the problem of hermetically sealing the cabin.
Date: February 1932
Creator: De Caria, Ugo
Item Type: Report
Partner: UNT Libraries Government Documents Department

Aeronautical education and research at the Swiss Institute of Technology in Zurich

Description: Progress in the scientific and practical fields of aviation has caused the Swiss Institute of Technology to organize lectures and practical training courses in all three branches of aeronautics and to found centers of scientific research, laboratories, etc., in order to supply the government and industries with scientifically and technically trained engineers.
Date: April 1931
Creator: Karner, L & Ackeret, J
Item Type: Report
Partner: UNT Libraries Government Documents Department

Aeronautical record : no. 1 (to June, 1923)

Description: "...considerations have prompted us to pay special attention to the development of aeronautical industries and aerial navigation as a commercial enterprise and to publish an analytical review of events in the aeronautical world and of the attendant problems.".
Date: December 1923
Item Type: Report
Partner: UNT Libraries Government Documents Department

The dangerous sideslip of a stalled airplane and its prevention

Description: This investigation covers only that phase of airplane accidents which are the result of sideslip. We examine the circumstances under which this occurs, study the behavior of present-day airplane types (monoplane, conventional and staggered biplane) therein and endeavor to find a solution whereby this danger may be avoided.
Date: September 1, 1931
Creator: Schmidt, Wilhelm & Fuchs, Richard
Item Type: Report
Partner: UNT Libraries Government Documents Department