Technical Report Archive & Image Library (TRAIL) - 331 Matching Results

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Drag or Negative Traction of Geared-Down Supporting Propellers in the Downward Vertical Glide of a Helicopter

Description: Discussed here are computations of drag or negative traction of geared down supporting propellers in the downward vertical glide of a helicopter. By means of Frounde's Theory, the maximum value of the drag of a windmill is calculated. For wooden propellers, the author finds that the difference between the drag and the weight is proportional to the number of blades and is larger for propellers of small diameter; thus it is 25 kg. for a six blade propeller with a diameter of 2 m. 50.
Date: September 1920
Creator: Toussaint, A.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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The Drag and Interference of a Nacelle in the Presence of a Wing

Description: A wing interference investigation was conducted to determine why the N.A.C.A. cowling did not yield the expected increase in speed when adapted to the outboard nacelles of trimotored airplanes. The results indicate that the drag and interference of the engine nacelle with the cowling, when combined with a thick wing, can be reduced from its value as originally applied by changing its position and fairing it into the wing.
Date: October 1929
Creator: Jacobs, Eastman N.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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The Impact on Seaplane Floats During Landing

Description: "In order to make a stress analysis of seaplane floats, and especially of the members connecting the floats with the fuselage, it is of great importance to determine the maximum pressure acting on the floats during landing. Here, the author gives a formula for maximum pressures during landing that permits one to apply experimental results to different bodies and different velocities. The author notes that the formula checks very well with experimental results" (p. 1).
Date: October 1929
Creator: von Karman, T.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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The effect of the wings of single engine airplanes on propulsive efficiency as shown by full scale wind tunnel tests

Description: An investigation was conducted to determine the effect of the wings on propulsive efficiency. The wings are shown to cause a reduction of 1 percent to 3 percent in propulsive efficiency, which is about the same for monoplane as well as biplane wings.
Date: October 1929
Creator: Weick, Fred E. & Wood, Donald H.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Notes on the Theory of the Accelerometer

Description: Report discusses several types of accelerometers and how they function. Methods for reducing error and determining the source of the error, including the best placement for the device, are included.
Date: May 1920
Creator: Warner, E. P.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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The Problem of the Helicopter

Description: Report discussing some of the issues regarding the design and operation of helicopters and the theoretical basis behind them. Some particular issues covered include propeller blade design, helicopters in forced descent, horizontal travel, and stability and control.
Date: May 1920
Creator: Warner, E. P.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Notes on Specifications for French Airplane Competitions

Description: Given here are the rules officially adopted by the Aeronautical Commission of the Aero Club of France for a flight competition to be held in France in 1920 at the Villacoublay Aerodrome. The prize will be awarded to the pilot who succeeds in obtaining the highest maximum and lowest minimum speeds, and in landing within the shortest distance.
Date: October 1920
Creator: Margoulis, W.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Tests of the Daimler D-IVa Engine at a High Altitude Test Bench

Description: Reports of tests of a Daimler IVa engine at the test-bench at Friedrichshafen, show that the decrease of power of that engine, at high altitudes, was established, and that the manner of its working when air is supplied at a certain pressure was explained. These tests were preparatory to the installation of compressors in giant aircraft for the purpose of maintaining constant power at high altitudes.
Date: October 1920
Creator: Noack, W. G.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Experience With Geared Propeller Drives for Aviation Engines

Description: An overview is given of experience with geared propeller drives for aviation engines. The development of gear wheels is discussed with emphasis upon bending stresses, compressive stresses, heating, and precision in manufacturing. With respect to the general arrangement of gear drives for airplanes, some principal rules of mechanical engineering that apply with special force are noted.
Date: September 1920
Creator: Kutzbach, K.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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The Problem of the Turbo-Compressor

Description: "In terminating the study of the adaptation of the engine to the airplane, we will examine the problem of the turbo-compressor, the first realization of which dates from the war; this will form an addition to the indications already given on supercharging at various altitudes. This subject is of great importance for the application of the turbo-compressor worked by the exhaust gases. Assuming that the increase of pressure in the admission manifold is the same in both cases, the pressure in the … more
Date: August 1920
Creator: Devillers, René
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Loads and Calculations of Army Airplanes

Description: By comparing airplanes of known strength that have resisted all the usual and even extreme air loads with those that under like conditions were found to be insufficiently strong, the researchers, aided by scientific investigations, developed standards which are satisfactory for the calculation of airplane structures. Given here are standards applicable to loads on wing trusses, load factors for use in stress analysis, load factors required in sand testing, loads on control surfaces, loads on wi… more
Date: February 1921
Creator: Stelmachowski
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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The Photographic Recording of Small Motions

Description: Methods and equipment for recording small and sometimes rapid motions by photographic means are described, and the efficacy of photographic recording in such instances is evaluated. The optical system consisting of the light source, the mirror or prism for transmitting motion to the emergent beam, and a means of bringing the rays into focus on the film are discussed. Attention is given to the critical issue of mirror mounting.
Date: November 1920
Creator: Norton, F. H.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Italian and French Experiments on Wind Tunnels

Description: Given here are the results of experiments conducted by Colonel Costanzi of the Italian Army to determine the influence of the surrounding building in which a wind tunnel was installed on the efficiency of the installation, and how the efficiency of the installation was affected by the design of the tunnel. Also given are the results of a series of experiments by Eiffel on 34 models of tunnels of different dimensions. This series of experiments was started in order to find out if, by changing th… more
Date: November 1920
Creator: Knight, William
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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The determination of the effective resistance of a spindle supporting a model aerofoil

Description: An attempt was made to determine the effect of spindle interference on the lift of the airfoil by measuring moments about the axis parallel to the direction of air flow. The values obtained are of the same degree as the experimental error, and for the present this effect will be neglected. The results obtained using a U.S.A. 15 wing (plotted here) show that the correction is nearly constant from 0 degrees to 10 degrees incidence and that at greater angles its value becomes erratic. At such angl… more
Date: January 1921
Creator: Davidson, W. E. & Bacon, D. L.
Item Type: Refine your search to only Report
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.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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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.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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The Dynamometer Hub

Description: The construction of the dynamometer hub is illustrated and explained, and its electrical and aviation motor tests, as well as those in free flight, described.
Date: September 1920
Creator: Stieber, W.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Crippling Strength of Axially Loaded Rods

Description: A new empirical formula was developed that holds good for any length and any material of a rod, and agrees well with the results of extensive strength tests. To facilitate calculations, three tables are included, giving the crippling load for solid and hollow sectioned wooden rods of different thickness and length, as well as for steel tubes manufactured according to the standards of Army Air Services Inspection. Further, a graphical method of calculation of the breaking load is derived in whic… more
Date: October 1921
Creator: Natalis, F. & Pawlowski, F. W.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Performance of a vane driven-gear pump

Description: Given here are the results of a test conducted in a wind tunnel on the performance of a vane-driven gear pump used to pump gasoline upward into a small tank located within the upper wing from which it flows by gravity to the engine carburetor. Information is given on the efficiency of the pump, the head resistance of the vanes, the performance and characteristics of the unit with and without housing about the vanes, the pump performance when motor driven, and resistance and power characteristic… more
Date: September 1921
Creator: Heald, R. H.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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The Factors That Determine the Minimum Speed of an Airplane

Description: The author argues that because of a general misunderstanding of the principles of flight at low speed, there are a large number of airplanes that could be made to fly several miles per hour slower than at present by making slight modifications. In order to show how greatly the wing section affects the minimum speed, curves are plotted against various loadings. The disposition of wings on the airplane slightly affects the lift coefficient, and a few such cases are discussed.
Date: March 1921
Creator: Norton, F. H.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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The Problem of Fuel for Aviation Engines

Description: Note presenting the physical properties which may be demanded of fuels for aviation use and the means that may be adopted by the engine manufacturers to properly meet the demands necessitated by the use of the fuel. Some of the factors that must be considered include its composition, the quantity available, the price per heat unit, and the possibility of keeping stocks in aerial ports both at home and abroad.
Date: July 1921
Creator: Kutzbach & James, W. S.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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The development of German Army airplanes during the war

Description: From Summary: "The author, who was a captain of the Reserves in the Technical Department of the Aviation Division (Board of Airplane Experts) during the war, shows what means were taken for the creation of new airplane types and what tests were employed for trying out their flying properties, capacities and structural reliability. The principal representative types of each of the classes of airplanes are described and the characteristics of the important structural parts are discussed. Data reg… more
Date: June 1921
Creator: Hoff, Wilhelm
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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The Employment of Airships for the Transport of Passengers: Indications on the Maximum Limits of Their Useful Load, Distance Covered, Altitude and Speed

Description: It was a conclusion of this detailed study of the practicality of using airships for carrying passengers that, although slow, airships are capable of carrying useful loads over long distances. However, it is noted that there is a certain limit to the advantages of large cubature. Beyond a certain point, the maximum altitude of the airship goes on decreasing, in spite of the fact that the range of action in the horizontal plane and the useful load go on increasing. The possibility of rapid climb… more
Date: August 1921
Creator: Nobile, Umberto
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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