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Göttingen Wind Tunnel for Testing Aircraft Models

Description: Given here is a brief description of the Göttingen wind tunnel for the testing of aircraft models, preceded by a history of its development. Included are a number of diagrams illustrating, among other things, a sectional elevation of the wind tunnel, the pressure regulator, the entrance cone and method of supporting a model for simple drag tests, a three-component balance, and a propeller testing device, all of which are discussed in the text.
Date: November 1920
Creator: Prandtl, L.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Horizontal Buoyancy in Wind Tunnels

Description: Note presenting an examination of horizontal buoyancy in wind tunnels, including an examination of the relative flow, static pressure gradient, horizontal buoyancy computation, and methods of computation in practical use are provided.
Date: November 1920
Creator: Zahm, A. F.
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 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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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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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.
Item Type: Refine your search to only Report
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.
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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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.
Item Type: Refine your search to only Report
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.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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The 300 H.P. Benz Aircraft Engine

Description: This report provides a description of the Benz 300 H.P. aircraft engine containing 12 cylinders placed at a 60° angle. It includes a detailed description of the development of the constructional points, particularly the cylinders, pistons, and connecting rods, as well as the engine fitting, lubrication, oil pumps, bearings, oil tank, fuel pump, carburetors, and cooling system. There are seven pages of illustrative figures at the end of the report.
Date: January 1921
Creator: Heller, A.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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N.A.C.A. Langley field wind tunnel apparatus: The tilting manometer

Description: A description is given of a tilting manometer designed to meet the requirements of a manometer for use in the wind tunnel at the Langley Memorial Aeronautical Laboratory. This gauge was designed to meet the requirements of a manometer in use in connection with a static pressure plate to indicate the wind speed in the tunnel. The requirements are noted. The sensitivity of the gauge must be made inversely proportional to the pressure to be measured. The gauge must be accurately and quickly set fo… more
Date: January 1921
Creator: Norton, F. H. & Bacon, D. L.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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The determination of downwash

Description: It is obvious that, in accordance with Newton's second law, the lift on an aerofoil must be equal to the vertical momentum communicated per second to the air mass affected. Consequently a lifting aerofoil in flight is trailed by a wash which has a definite inclination corresponding to the factors producing the lift. It is thought that sufficient data, theoretical and experimental, are now available for a complete determination of this wash with respect to the variation of its angle of inclinati… more
Date: January 1921
Creator: Diehl, Walter S.
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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Measurements of Rudder Moments on an Airplane During Flight

Description: Tests indicated that: 1) C airplanes with two struts are extremely susceptible to aileron maneuvers, slight alterations of the aileron sufficing to compensate great unequalized moments; 2) great unequalized moments can be produced or neutralized by the unequalized alternation of the angle of attack below the outer and inner struts. Adjustment below the outer strut is the more effective of the two. 3) When a load of bombs is suspended beyond the center of the airplane, below the wings, the bombs… more
Date: January 1921
Creator: Heidelberg, V.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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On the Resistance of Spheres and Ellipsoids in Wind Tunnels

Description: Note presenting a study of the influence exercised on the results of measurements by the dimensions and type of the tunnels used in aerodynamic laboratories, and on the comparison of the results with observations made in motionless and unlimited air.
Date: January 1921
Creator: Riabouchinsky, D. P.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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The optical wing aligning device of the Langley Field tunnel

Description: Described here is a convenient and accurate method of aligning the wing chord with the airflow. The device was developed to permit rapid and accurate alignment of airfoils and models with the airstream passing through the tunnel. It consists of three main parts: a projector, a reflector, and a target. The arrangement, which is shown in a figure, has proven satisfactory in operation. It is far better than the old method of sighting across a long batten, as the operator of a balance may see the t… more
Date: January 1921
Creator: Norton, F. H. & Bacon, D. L.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Causes of cracking of ignition cable

Description: From Summary: "The experiments described here show that the cracking at sharp bends, observed in the insulation of internal combustion engine high tension ignition wires after service, is due to a chemical attack upon the rubber by the ozone produced by the electric discharge that takes place at the surface of the cable. This cracking does not occur if the insulating material is not under tension, or if the cable is surrounded by some medium other than air. But it does occur even if the insulat… more
Date: February 1921
Creator: Dempsey, J. B. & Silsbee, F. B.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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The Effect of the Nature of Surfaces on Resistance as Tested on Struts

Description: The chief concern was to measure the variations of resistance brought about by the nature of the surface of the struts. The struts were spanned with aviation linen, and then covered with one coat of varnish. The top surface was not perfectly smooth after this treatment, being slightly rough owing to the threads and raised fibers of the fabric. The results of the measurements of the surfaces are shown by the dotted lines of the curves plotted in several figures.
Date: February 1921
Creator: Wieselsberger, G.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Effect of the Reversal of Air Flow Upon the Discharge Coefficient of Durley Orifices

Description: Experiments were conducted to obtain information on the relationship between the coefficients for flow in two directions through thin plate orifices at low velocities. The results indicate that the ratio of the orifice discharge coefficient from standard orifice C(sub s)(sup 1) to the discharge coefficient from the reverse flow C(sub s) is always less than unity with increasing ratio of box area to orifice area. Even for areas as low as twenty, the ratios of the coefficients are not much less t… more
Date: February 1921
Creator: Ware, Marsden
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Effect of the Reversal of Air Flow Upon the Discharge Coefficient of Durley Orifices

Description: Note presenting an experiment to obtain information regarding the relationship between the coefficients for flow in the two directions through an inlet. The results indicate that the ratio of the orifice discharge coefficient from standard orifice to the discharge coefficient from reverse flow is always less than unity, but approaches unity with increasing ratio of box area to orifice area, and that even for a ratio of areas as low as twenty the ratios of the coefficients is not much less than … more
Date: February 1921
Creator: Ware, Marsden
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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Note on the Resistance of Polished Cylinders (and Cylindrical Wires) With Generatrices Perpendicular to the Airstream

Description: Report presenting a review of currently published documents regarding the resistance of polished cylinders with generators perpendicular to the airstream. The discrepancies between these various studies are pointed out.
Date: February 1921
Creator: Toussaint, A.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Airplane Crashes: Engine Troubles: A Possible Explanation

Description: The aim was to bring attention to what might be the cause of some aircraft accidents for which there was no satisfactory explanation. The author notes that in testing aircraft accidents at the Bureau of Standards, it happened frequently that the engine performance became erratic when the temperature of the air entering the carburetor was between 0 C and 20 C. Investigation revealed the trouble to have been caused by the formation and collection of snow somewhere between the entrance to the carb… more
Date: March 1921
Creator: Sparrow, Stanwood W.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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