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Application and testing of transparent plastics used in airplane construction

Description: This report discusses the efforts being made to remove the source of danger to passengers arising from the fracturing of silicate glass and some of the alternatives presented include: single-layer safety glass, multi-layer safety glass, transparent plastic resins.
Date: November 1938
Creator: Riechers, K. & Olms, J.
Partner: UNT Libraries Government Documents Department
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Behavior of a Plate Strip Under Shear and Compressive Stresses Beyond the Buckling Limit

Description: The present report is an extension of previous theoretical investigations on the elastic behavior of a plate under compression and shear in the region above the critical. The main object is the clarification of the behavior immediately above the buckling limit since no theoretical expressions for this range have thus far been found and since experimentally, too, any degree of regularity in the behavior of the plate in the range between the critical load and about three to four times the critica… more
Date: July 1938
Creator: Kromm, A. & Marguerre, K.
Partner: UNT Libraries Government Documents Department
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Behavior of Static Pressure Heads at High Speeds

Description: "Memorandum presenting the development of a static pressure head for high speeds. These tests proved the practicability of static pressure heads at speeds up to 400 km/h (248.5 mph). It weighs 6.5 kg or 2.5 times as much as the old head. The position of the pressure head below the airplane was determined by bearing method at different speeds and for different lengths of suspension" (p. 1).
Date: June 1938
Creator: Danielzig, Helmut
Partner: UNT Libraries Government Documents Department
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The Buckling of Curved Tension-Field Girders

Description: "The present paper reports on experiments made to determine the buckling load under shear of circular curved tension-field webs. The buckling load of the webs may be expressed with reference to the buckling load of the stiffeners. It is found that within the explored range the buckling load is approximately twice as great as that of the identically stiffened flat wall of equal web depth" (p. 1).
Date: January 1938
Creator: Limpert, G.
Partner: UNT Libraries Government Documents Department
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Calculation of Load Distribution in Stiffened Cylindrical Shells

Description: "Thin-walled shells with strong longitudinal and transverse stiffening (for example, stressed-skin fuselages and wings) may, under certain simplifying assumptions, be treated as static systems with finite redundancies. In this report the underlying basis for this method of treatment of the problem is presented and a computation procedure for stiffened cylindrical shells with curved sheet panels indicated. A detailed discussion of the force distribution due to applied concentrated forces is give… more
Date: June 1938
Creator: Ebner, H. & Köller, H.
Partner: UNT Libraries Government Documents Department
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The Conversion of Energy in a Radiator

Description: It was a worthwhile task to research methods to lower the cooling drag of radiators. And the success of these efforts has been so great that without this research the modern high-speed airplane would have decidedly inferior performance. It is the purpose of this report to give a comprehensive discussion of all the fundamental principles and phenomena that offer a key to understanding modern cooling problems.
Date: July 1938
Creator: Weise, A.
Partner: UNT Libraries Government Documents Department
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The design of floats

Description: Following a summary of the multiplicity of domestic and foreign floats and a brief enumeration of the requirements of floats, the essential form parameters and their effect on the qualities of floats are detailed. On this basis a standard float design is developed which in model families with varying length/beam ratio and angle of dead rise is analyzed by an experimental method which permits its best utilization on any airplane.
Date: April 1938
Creator: Sottorf, W.
Partner: UNT Libraries Government Documents Department
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Distribution of Temperatures Over an Airplane Wing With Reference to the Phenomena of Ice Formation

Description: The results obtained from the present study of temperature distribution over an airplane wing afford means for making the following statements as regards the conditions of ice accretion and the use of a thermic anti-icer or de-icer: 1) Ice can form on a wing only when the temperature is below or hovering around zero. 2) The thermic effects produced on contact of the air with the moving wing rather oppose ice accretion. 3) The thermic procedure in the fight against ice accretion on the wing cons… more
Date: December 1938
Creator: Brun, Edmond
Partner: UNT Libraries Government Documents Department
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The Dornier wind tunnel

Description: After completion of the required calibrations, the Dornier open-throat tunnel is now in operation. With an elliptic test section of 3 by 4 m (9.84 by 3.12 ft.), its length is 7 m (22.97 ft.), its maximum horsepower 800, and its maximum air speed 60 m/s (134.2 mph). As to local uniformity of velocity, static pressure as well as jet direction, and turbulence factor, this tunnel is on par with those of the good German and foreign research labs.
Date: June 1938
Creator: Schlichting, H.
Partner: UNT Libraries Government Documents Department
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Effect of Air-Fuel Ratio on Detonation in Gasoline Engines

Description: Memorandum presenting a study of the effect of mixture strength on detonation, which may be divided into two parts, namely: a) the measurement of the effect in engines; and b) the explanation of the effect. This is because of the richness of the mixture has a very pronounced effect on the detonation in a gasoline engine.
Date: March 1938
Creator: Peletier, L. A.
Partner: UNT Libraries Government Documents Department
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Effect of propeller slipstream on wing and tail

Description: The results of wind tunnel tests for the determination of the effect of a jet on the lift and downwash of a wing are presented in this report. In the first part, a jet without rotation and with constant velocity distribution is considered - the jet being produced by a specially designed fan. Three-component, pressure distribution, and downwash measurements were made and the results compared with existing theory. The effect of a propeller slipstream was investigated in the second part. In the tw… more
Date: August 1938
Creator: Stüper, J.
Partner: UNT Libraries Government Documents Department
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The Effective Width of Curved Sheet After Buckling

Description: This report describes experiments made for the purpose of ascertaining the effective width of circularly curved sheet under pure flexural stress. A relation for the effective width of curved sheets is established. Experiments were made with circular cylinders compressed in longitudinal direction. The sheets were rigidly built in at the sides parallel to the axis of the cylinder.
Date: November 1938
Creator: Wenzek, W. A.
Partner: UNT Libraries Government Documents Department
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Engines and Propellers for Powered Gliders and Light Airplanes

Description: The object of the present paper is to consider the interaction of engine, propeller, and airplane for the low-power range. The discussion is presented in a form so as to provide the engine builder with a basis in his selection in the type of engine required, a suitable selection being possible only in connection with considerations on the best possible propeller.
Date: March 1938
Creator: Gropp, H.
Partner: UNT Libraries Government Documents Department
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Experimental Study of Ignition by Hot Spot in Internal Combustion Engines

Description: "In order to carry out the contemplated study, it was first necessary to provide hot spots in the combustion chamber, which could be measured and whose temperature could be changed. It seemed difficult to realize both conditions working solely on the temperature of the cooling water in a way so as to produce hot spots on the cylinder wall capable of provoking autoignition. Moreover, in the majority of practical cases, autoignition is produced by the spark plug, one of the least cooled parts in … more
Date: August 1938
Creator: Serruys, Max
Partner: UNT Libraries Government Documents Department
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Flow in Smooth Straight Pipes at Velocities Above and Below Sound Velocity

Description: "To investigate the laws of flow of compressible fluids in pipes, tests were carried out with air flowing at velocities below and above that of sound in straight smooth pipes. Air was chosen as the flow medium. In order that the effect of compressibility may be brought out most effectively, the velocity should lie between 100 and 500 m/s (200 and 1,000 mph); that is, be of the order of magnitude of the velocity of sound in air. The behavior of the compression shock in a smooth cylindrical pipe … more
Date: January 1938
Creator: Frössel, W.
Partner: UNT Libraries Government Documents Department
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The Focke helicopter

Description: This report presents some of the problems concerning tests of helicopters, such as forced landings, controllability and stability, general safety, piloting maneuvers, performance, servicing, and the production of lift of a propeller. Test flights are described including a 67.67 mph flight by Hanna Reitsch.
Date: April 1938
Creator: Focke, H.
Partner: UNT Libraries Government Documents Department
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Heat-Stressed Structural Components in Combustion-Engine Design

Description: "Heated structural parts alter their shape. Anything which hinders free heat expansion will give rise to heat stresses. Design rules are thus obtained for the heated walls themselves as well as for the adjoining parts. An important guiding principle is that of designing the heat-conducting walls as thin as possible" (p. 1).
Date: September 1938
Creator: Kraemer, Otto
Partner: UNT Libraries Government Documents Department
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The Influence of Notches Under Static Stress

Description: From the described experiments it is seen that notches are a potential source of strength decrease even under static stress, which the designer must take into consideration. Section I is a general treatment of notch influence under the various types of stresses. Section II treats the influence of notches in thin sheet as is used in airplane construction.
Date: May 1938
Creator: Matthaes, K.
Partner: UNT Libraries Government Documents Department
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Investigation of Ignition and Combustion Processes of Diesel Engines Operating With Turbulence and Air-Storage Chambers

Description: The flame photographs obtained with combustion-chamber models of engines operating respectively, with turbulence chamber and air-storage chambers or cells, provide an insight into the air and fuel movements that take place before and during combustion in the combustion chamber. The relation between air velocity, start of injection, and time of combustion was determined for the combustion process employing a turbulence chamber.
Date: April 1938
Creator: Petersen, Hans
Partner: UNT Libraries Government Documents Department
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Investigations on the Downwash Behind a Tapered Wing With Fuselage and Propeller

Description: "The new downwash measurements behind a tapered wing with parallel center section described in the present report can be brought into good agreement with theoretical calculations if made on the basis of not-rolled-up vortex sheet and allowance is made for the lowering of the sheet. The test values are about 1 degree higher than the "upper limit" established for it, as against approximately 0.5 degrees in the earlier tests behind a rectangular and elliptical wing. The measurements on lateral axe… more
Date: September 1938
Creator: Muttray, H.
Partner: UNT Libraries Government Documents Department
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The Lift Distribution of Wings With End Plates

Description: The object of the present report is to ascertain the relationship of the circulation distribution over the wing and of the lift to the height and position of the end plate. The side forces and moments on the end plates were also determined. It is found that moving an end plate of certain length up from the symmetrical position, is followed by a slight increase of the total lift.
Date: April 1938
Creator: Mangler, W.
Partner: UNT Libraries Government Documents Department
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Load Tests on a Stiffened Circular Cylindrical Shell

Description: The present report describes tests in which the stress distribution may be determined in a stiffened circular cylindrical shell loaded longitudinally at four symmetrically situated points. As being of particular importance are the cases investigated of groups of bending and arching or convexing forces, respectively. From the stress measurements on the longitudinal stiffeners, the shear stresses and the bulkhead ring stresses in the skin could be evaluated.
Date: May 1938
Creator: Schapitz, E. & Krümling, G.
Partner: UNT Libraries Government Documents Department
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Model Experiments on the Forces and Moments Acting on an End Plate Fitted to a Wing

Description: "This paper reports on 4-component balance measurements with and without angle of sideslip made on an airfoil with end plate at one tip. In addition, pressure distribution measurements on the end plate served as a basis for the determination of the forces on the end plate and for the bending moments" (p. 1).
Date: April 1938
Creator: Schrenk, O.
Partner: UNT Libraries Government Documents Department
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