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Duralumin - Defects and Failures

Description: It is proposed in this paper to identify some of the defects and failures in duralumin most frequently encountered by the aircraft industry with a view to indicate their importance. The defects and failures in duralumin may be classified into the following groups: 1) defects produced during manufacture; 2) defects produced during fabrication; 3) corrosion and erosion; and 4) fatigue failures. Only the first two will be covered in this report.
Date: December 1927
Creator: Nelson, Wm.
Partner: UNT Libraries Government Documents Department

Calculating Thrust Distribution and Efficiency of Air Propellers

Description: I am now proposing a method for the preliminary approximate calculation of the thrust distribution and efficiency of air propellers under any operating conditions. Our task becomes the following, namely, to determine the speed relations and the forces developed on a section with a given direction and velocity of the air current, a problem which can be solved with the aid of the momentum theory.
Date: December 1927
Creator: Bienen, Theodor
Partner: UNT Libraries Government Documents Department

Increasing Lift by Releasing Compressed Air on Suction Side of Airfoil

Description: The investigation was limited chiefly to the region of high angles of attack since it is only in this region that any considerable change in the character of the flow can be expected from such artificial aids. The slot, through which compressed air was blown, was formed by two pieces of sheet steel connected by screws at intervals of about 5 cm. It was intended to regulate the width of the slot by means of these screws. Much more compressed air was required than was originally supposed, hence all the delivery pipes were much too small. This experiment, therefore, is to be regarded as only a preliminary one.
Date: December 1927
Creator: Seewald, F.
Partner: UNT Libraries Government Documents Department

"Gloster" High Lift Biplane Wings

Description: "The main object of these wings was to obtain a high lift without increasing the total drag, and the idea was conceived that, by using a deep high-lift section for the top wing and a medium section for the bottom wing, the mutual interference between the two would be such as to give greater efficiency of the combination as compared with two wings of equal section" (p. 1).
Date: December 1927
Creator: Preston, H. E.
Partner: UNT Libraries Government Documents Department

The Comparative Performance of Roots Type Aircraft Engine Superchargers as Affected by Change in Impeller Speed and Displacement

Description: "This report presents the results of tests made on three sizes of roots type aircraft engine superchargers. The impeller contours and diameters of these machines were the same, but the length were 11, 8 1/4, and 4 inches, giving displacements of 0.509, 0.382, and 0.185 cubic foot per impeller revolution. The information obtained serves as a basis for the examination of the individual effects of impeller speed and displacement on performance and of the comparative performance when speed and displacement are altered simultaneously to meet definite service requirements" (p. 3).
Date: December 23, 1927
Creator: Ware, Marsden & Wilson, Ernest E.
Partner: UNT Libraries Government Documents Department

Insects Injurious to the Rice Crop.

Description: Describes several different pests which attack rice crops in the United States, including: stinkbugs, water weevils, borers, and several other minor pests; also describes the methods of controlling these pests.
Date: December 1927
Creator: Ingram, J. W. (Jesse Wilburn), b. 1900
Partner: UNT Libraries Government Documents Department

The Characteristics of the N.A.C.A 97, Clark Y, and N.A.C.A. M6 Airfoils with Particular Reference to the Angle of Attack

Description: Report examining the aerodynamic characteristics of three airfoil sections as determined in the variable density wind tunnel. Particular attention is given to the relation of the characteristics to the angle of attack and their use in airplane design.
Date: December 1927
Creator: Higgins, George J.
Partner: UNT Libraries Government Documents Department

Water-pressure distribution on seaplane float

Description: The investigation presented in this report was conducted for the purpose of determining the distribution and magnitude of water pressures likely to be experienced on seaplane hulls in service. It consisted of the development and construction of apparatus for recording water pressures lasting one one-hundredth second or longer and of flight tests to determine the water pressures on a UO-1 seaplane float under various conditions of taxiing, taking off, and landing. The apparatus developed was found to operate with satisfactory accuracy and is suitable for flight tests on other seaplanes. The tests on the UO-1 showed that maximum pressures of about 6.5 pounds per square inch occur at the step for the full width of the float bottom. Proceeding forward from the step the maximum pressures decrease in magnitude uniformly toward the bow, and the region of highest pressures narrows toward the keel. Immediately abaft the step the maximum pressures are very small, but increase in magnitude toward the stern and there once reached a value of about 5 pounds per square inch. (author).
Date: December 22, 1927
Creator: Thompson, F. L.
Partner: UNT Libraries Government Documents Department