Technical Report Archive & Image Library (TRAIL) - 50 Matching Results

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Experiments With an Airfoil From Which the Boundary Layer Is Removed by Suction

Description: "Our attempts to improve the properties of airfoils by removing the boundary layer by suction, go back to 1922. The object of the suction is chiefly to prevent the detachment of the boundary layer from the surface of the airfoil. At large angles of attack, such detachment prevents the attainment of the great lift promised by the theory, besides greatly increasing the drag, especially of thick airfoils. This report gives results of those experiments" (p. 1).
Date: August 1926
Creator: Ackeret, J.; Betz, A. & Schrenk, O.
Partner: UNT Libraries Government Documents Department
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Tail Planes

Description: This report presents methods by which the cells of large commercial airplanes may be reduced. The tail of large airplanes represent an area where considerable improvement in weight and size reduction can be attained.
Date: August 1926
Creator: Constantin, L.
Partner: UNT Libraries Government Documents Department
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Mixing and Ignition in Supercharged Engines

Description: Memorandum presenting two principal methods of mixing for carburetor engines, one using a suction carburetor and the other using a pressure carburetor. An investigation of the spark plugs in the engines and how to design them so they can resist high levels of heat is also provided.
Date: April 1926
Partner: UNT Libraries Government Documents Department
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Behm Acoustic Sounder for Aircraft

Description: The Behm acoustic sounder for aircraft enables the barometric determination for the altitude by night or fog and therefore promises to prove of great importance in safeguarding air traffic.
Date: January 1926
Partner: UNT Libraries Government Documents Department
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Protection of wooden airplane parts against moisture by means of varnish

Description: The objects of the experiments herein described were to test the protection afforded by Valspar oil varnish against the absorption of moisture by wooden airplane parts and the consequent changes in their elastic properties and to compare some of the best Dutch varnishes with Valspar.
Date: February 1926
Creator: Wolff, E. B. & Van Ewijk, L. J. G.
Partner: UNT Libraries Government Documents Department
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Change of 180 Degrees in the Direction of a Uniform Current of Air

Description: In the construction of aerodynamic tunnels, it is a very important matter to obtain a uniform current of air in the sections where measurements are to be made. The straight type ordinarily used for attaining a uniform current and generally recommended for use, has great defects. If we desire to avoid these defects, it is well to give the canals of the tunnel such a form that the current, after the change of direction of its asymptotes, approximates a uniform and rectilinear movement. But for th… more
Date: February 1926
Creator: Witoszynski, C.
Partner: UNT Libraries Government Documents Department
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Kirsten-Boeing Propeller

Description: The advantages of the Kirsten-Boeing propeller consist essentially in the adjustability of the thrust in any desired direction, in the plane perpendicular to the axis of rotation of the system, and in its high efficiency. The propeller, which greatly resembles the paddle wheels used on river steamers, differs fundamentally from the latter, in that all the blades work simultaneously in the fluid medium (air or water).
Date: February 1926
Creator: Sachse, H.
Partner: UNT Libraries Government Documents Department
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Approximate Calculation of the Static Longitudinal Stability of Airplanes

Description: It seems desirable to have some simple method for calculating quickly and with sufficient accuracy: 1) the correct position of the center of gravity; 2) the requisite tail-group dimensions; 3) and the course of the wing and tail-group moments. In out deductions, we will first replace the biplane (disregarding the effect of stagger, decalage and induced drag) by an equivalent monoplane, whose dimensions and position in space can be approximately determined in a simple manner.
Date: November 1926
Creator: Bienen, Theodor
Partner: UNT Libraries Government Documents Department
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Experiments on Autorotation

Description: This article deals principally with Professor Bairstow's experiments on autorotation, in which the wing is free to rotate about an axis in its plane of symmetry, which axis is parallel with the direction of the wind.
Date: September 1926
Creator: Anderlik, E.
Partner: UNT Libraries Government Documents Department
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Flight Tests on Airplanes

Description: This report presents test procedures, methods, and instruments for flight testing of aircraft. Dynamic-pressure gauges are discussed at length.
Date: April 1926
Creator: Koppe, Heinrich
Partner: UNT Libraries Government Documents Department
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Experiments With a Sphere From Which the Boundary Layer Is Removed by Suction

Description: The task of removing the boundary layer by suction consists in producing, in place of the ordinary flow with the formation of vortices, another kind of flow in which the vortices are eliminated by drawing small quantities of fluid from certain points on the surface into the interior of the body. The experiments with a sphere, which constitute the subject of this report, were made early in the present year .
Date: November 1926
Creator: Schrenk, Oskar
Partner: UNT Libraries Government Documents Department
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Metal Airplane Construction

Description: It has long been thought that metal construction of airplanes would involve an increase in weight as compared with wood construction. Recent experience has shown that such is not the case. This report describes the materials used, treatment of, and characteristics of metal airplane construction.
Date: May 1926
Partner: UNT Libraries Government Documents Department
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First Experiences With the Rotating Laboratory

Description: This report describes experiences with a rotating cylinder to explore the effects of motion and flow upon human sensory organs. One observation was that the variation of the resultant line of gravity (from gravity and centrifugal force) was not felt so strongly as might be expected. The impressions produced by the physical effects on the members of the body, especially the ones caused by the deflecting force (Coriolis force), are exactly what the laws of physics would lead us to expect, althoug… more
Date: July 1926
Creator: Prandtl, L.
Partner: UNT Libraries Government Documents Department
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Recent Experiments With Large Seaplanes

Description: This report covers the following aspects of large seaplane design and construction: heavy wing loading; propeller design; how the motion of the airplane is affected by increasing the dihedral angle; power plants; floats; and the hull.
Date: March 1926
Creator: Rohrbach, Adolf
Partner: UNT Libraries Government Documents Department
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Slip Stream Effect

Description: "The horizontal tail surfaces of a new airplane usually are proportional so that the curve of moment about the center of gravity, combined with a similar curve for the wings alone, gives a composite curve which provides a certain specified degree of static stability. With the application of power three additional factors must be considered in calculations: the moment of the propeller thrust; the change in the velocity of the air over the tail due to the slipstream; and the change in direction o… more
Date: March 1926
Creator: Montieth, Charles N.
Partner: UNT Libraries Government Documents Department
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The fundamental principles of high-speed semi-diesel engines. Part 1: a general discussion of the subject of fuel injection in diesel engines and detailed descriptions of many types of injection nozzles

Description: Three questions relating to the technical progress in the utilization of heavy oils are discussed. The first question considers solid injection in high-speed automobile engines, the second concerns the development of the hot-bulb engine, and the third question relates to the need for a more thorough investigation of the processes on which the formatation of combustible, rapidly-burning mixtures depend.
Date: April 1926
Creator: Büchner
Partner: UNT Libraries Government Documents Department
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Removing boundary layer by suction

Description: "Through the utilization of the "Magnus effect" on the Flettner rotor ship, the attention of the public has been directed to the underlying physical principle. It has been found that the Prandtl boundary-layer theory furnishes a satisfactory explanation of the observed phenomena. The present article deals with the prevention of this separation or detachment of the flow by drawing the boundary layer into the inside of a body through a slot or slots in its surface" (p. 1).
Date: January 1926
Creator: Ackeret, J.
Partner: UNT Libraries Government Documents Department
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Experiments With Rotating Cylinders in Combination With Airfoils

Description: Memorandum presenting an investigation of whether rotating cylinders can be advantageously used in combination with airfoils in airplane construction.
Date: October 1926
Creator: Frey, Kurt
Partner: UNT Libraries Government Documents Department
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Take-Off Distance for Airplanes

Description: There are two principal ways in which the total take-off distance (taxying plus hovering plus the first part of the climb) can be reduced to a minimum. These are: 1) taxying and hovering until the maximum speed has been attained close to the ground and then changing to a steep rapid climb; 2) lifting the airplane from the ground as soon as possible and then climbing at a relatively large angle of attack. These cases, as well as all the other conceivable combinations, can be expressed with a sin… more
Date: September 1926
Creator: Pröll, A.
Partner: UNT Libraries Government Documents Department
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Devices for Prevention of Stalled Flight

Description: Memorandum describing warning or correcting devices based on the registering of two distinct factors, the air speed and the angle of attack. The authors of the report define the conditions for the flight of an airplane and then study the causes of stalled flight in the different cases where it can occur.
Date: November 1926
Creator: Mazer, Paul
Partner: UNT Libraries Government Documents Department
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Kinetographic Flow Pictures

Description: A method is presented for photographing the flow of fluids with a kinetograph.
Date: May 1926
Creator: Prandtl, L. & Tietjens, O.
Partner: UNT Libraries Government Documents Department
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