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Design of Recording Wind Tunnel Balances

Description: Given here is a description of the design of a scientific recording wind tunnel balance. It was decided that the most satisfactory arrangement would be a rigid ring completely surrounding the tunnel or wind stream, so that the model could be supported from it by wires or any arrangement of spindles. The forces and moments acting on this ring can then be recorded by suitable weighing apparatus. The methods available for recording forces on the arms are explained. The proposed type of balance wil… more
Date: December 1920
Creator: Norton, F. H.
Partner: UNT Libraries Government Documents Department
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High thermal efficiency in airplane service

Description: Described here is a method by which high average fuel economy has been achieved in aircraft engines. Details are given of the design of certain foreign engines that employ an unusual type of fuel-air ratio control in which the change in power produced by a mixture change is due almost entirely to the change in the power producing ability of the unit weight of the mixture. The safety and performance features of this type of control are explained.
Date: December 1920
Creator: Sparrow, S. W.
Partner: UNT Libraries Government Documents Department
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Instrument for measuring engine clearance volumes

Description: With the advent of the V type engine, a new method to measure the clearance volume in cylinders was needed. It was suggested that this measurement could be made by a process which consisted essentially of simultaneously changing both a known and unknown volume of gas by a known amount and then calculating the magnitude of the unknown from the resulting difference in pressure between the two. An instrument based on this design is described.
Date: December 1920
Creator: Sparrow, S. W.
Partner: UNT Libraries Government Documents Department
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Progress Made in the Construction of Giant Airplanes in Germany During the War

Description: The construction of giant airplanes was begun in Germany in August, 1914. The tables annexed here show that a large number of airplanes weighing up to 15.5 tons were constructed and tested in Germany during the War, and it is certain that no other country turned out airplanes of this weight nor in such large numbers. An examination of the tables shows that by the end of the War all the manufacturers had arrived at a well-defined type, namely an airplane of about 12 tons with four engines of 260… more
Date: December 1920
Creator: Baumann, A.
Partner: UNT Libraries Government Documents Department
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The Steadiness Factor in Engine Sets

Description: Technical notes discussing the steadiness factor in engines and the calculations that can be used to arrive at it. Factors affecting the steadiness factor are detailed, including the mass of parts, torque, engine rotation, and power.
Date: December 1920
Creator: Margoulis, W.
Partner: UNT Libraries Government Documents Department
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A Variable Speed Fan Dynamometer

Description: Fan brakes used as absorption dynamometers in testing internal combustion engines have the disadvantage that a given fan will run only at one speed when the engine is delivering full power. In order to be able to vary the speed at which a given power will be absorbed, English manufacturers have for some time been using a cylindrical housing around the fan with one or two variable openings in the periphery. Here, results are given of tests conducted to determine how great a range of speed can be… more
Date: December 1920
Creator: Wood, Karl D.
Partner: UNT Libraries Government Documents Department
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Dependence of Propeller Efficiency on Angle of Attack of Propeller Blade

Description: In order to determine the maximum and the most favorable pitch for a propeller, it was found desirable to investigate the dependence of propeller efficiency on the angle of attack of the propeller blade. The results of a few experiments are given to show that propeller blades conduct themselves just like airplane wings with reference to the dependence of their efficiency on their angle of attack.
Date: December 1921
Creator: Borck, Hermann
Partner: UNT Libraries Government Documents Department
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Effects of Varying the Relative Vertical Position of Wing and Fuselage

Description: "The object of this series of experiments was to determine the influence of the relative vertical position of wing and fuselage on the efficiency of the wing. Since the longitudinal position of the wing can be varied but slightly with reference to the center of gravity in a normal airplane, it was kept constant in the experiments to be described and only the vertical position of the wing with reference to the fuselage was varied" (p. 1).
Date: December 1921
Creator: Prandtl, L.
Partner: UNT Libraries Government Documents Department
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Ground Influence on Aerofoils

Description: The question of ground influence on airplanes has recently attracted some attention in view of the claims made by certain designers that the landing speed of their airplanes is much decreased by an increase in lift coefficient due to the proximity of the ground in landing. The results of wind tunnel tests indicate that ground effect is not entirely beneficial. It decreases the landing speed and cushions the landing shock somewhat. However, it does so at the expense of an increased length of pre… more
Date: December 1921
Creator: Raymond, Arthur E.
Partner: UNT Libraries Government Documents Department
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A Mechanical Device for Illustrating Airplane Stability

Description: An instrument is described which will illustrate completely in a qualitative sense the longitudinal stability characteristics of an airplane. The instrument is primarily of use for the lecture room, but it is hoped that ultimately it will be possible to obtain quantitative results from it.
Date: December 1921
Creator: Norton, F. E.
Partner: UNT Libraries Government Documents Department
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Mutual Influence of Wings and Propeller

Description: Report presenting an experiment consisting of an aerofoil and propeller in order to discover the mutual influence between the two components and variations in moment due to the propeller influence.
Date: December 1921
Creator: Prandtl, L.
Partner: UNT Libraries Government Documents Department
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Balloon Fabrics Made of Goldbeater's Skins

Description: Goldbeater's skin, which is the prepared outside membrane of the large intestine of an ox, is examined as a balloon fabric and details of how goldbeater's skin is prepared for use are provided. The construction techniques employed by Germany, France, and England are all discussed.
Date: December 1922
Creator: Chollet, L.
Partner: UNT Libraries Government Documents Department
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Commercial Airplanes and Seaplanes: Thick Wings or Thin Wings - All Metal or Mixed Construction

Description: In this report we will consider, as the dominating characteristic, either the load carried, the speed, the radius of action, the fuel consumption, the activity of transport, or, lastly, the qualities of comfort and safety. The first four factors determine the theoretical efficiency, while the others determine its practical efficiency.
Date: December 1922
Creator: Point
Partner: UNT Libraries Government Documents Department
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Depreciation of Aircraft

Description: Report presenting an examination of the concept that aircraft are essentially fragile and deteriorate rapidly when in service, which the author considers to be a misunderstanding due to the intense conditions occurring during war. Some examples of commercial airplane lines that have been running for several years and some potential deterioration costs that must be considered are provided.
Date: December 1922
Creator: Warner, Edward P.
Partner: UNT Libraries Government Documents Department
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Aeronautical Record: No. 1 (to June, 1923)

Description: Memorandum presenting an overview of the development of aeronautical industries and commercial aircraft as well as some of the problems that are resulting from it. Details of the aeronautical budget in various countries, organization of the air service, material exports, and airline operations are provided.
Date: December 1923
Partner: UNT Libraries Government Documents Department
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Compressive Strength of Tapered Airplane Struts

Description: Methods are here given for ascertaining the value of n in Euler's simplified formula, P = n (EI/l(sup 2)), for the compressive strength of tapered airplane struts, by estimating from curves and by calculation.
Date: December 1923
Creator: Lewe, Viktor
Partner: UNT Libraries Government Documents Department
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Experiments With Fabrics for Covering Airplane Wings, to Determine Effect of Method of Installation

Description: Note presenting some information on the effect of changes in the loading and in the disposition of the supporting framework on the covering fabric. The magnitude of the air forces to be taken into account and the corresponding factors of safety to be expected will be covered in a future report. Tables regarding some of these fabric characteristics are provided.
Date: December 1923
Creator: Pröll, A.
Partner: UNT Libraries Government Documents Department
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Factors of Safety

Description: Factors of safety serve three purposes: provides against trouble arising from unexpectedly large loads, allows for imperfections of workmanship, represents a depreciation allowance. A consideration of these safety factors is provided in this report.
Date: December 1923
Creator: Warner, Edward P.
Partner: UNT Libraries Government Documents Department
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The Nichols Wing Cutting Equipment

Description: Described here is wing cutting equipment for the economical production of metal wings for wind tunnel models. The machine will make any size of constant-section wing or strut up to one-sixth inch chord by 36-inch span and up to a thickness of one and one-quarter inches. It cuts a smooth, true model that is accurate to within two-thousandths of an inch on any ordinate. The holding jaws are so designed as to leave the model free of chip marks, and the only hand finishing necessary after the cutti… more
Date: December 1923
Creator: Ford, James B.
Partner: UNT Libraries Government Documents Department
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Reduction in Efficiency of Propellers Due to Slipstream

Description: "In the slipstream behind a propeller there is a considerable amount of kinetic energy which has been imparted to it by the engine without producing any corresponding propeller thrust. The increased absorption of power reduces the propeller efficiency. Attention has been previously directed to this question by Bendemann and Madelung and other writers. Their contribution serves to verify a simple method of calculating the reduction in the propeller efficiency due to the slip stream" (p. 1).
Date: December 1923
Creator: Munk, Max M.
Partner: UNT Libraries Government Documents Department
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