Technical Report Archive & Image Library (TRAIL) - 380 Matching Results

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The Breda Wind Tunnel

Description: A description of the design and construction of the Breda wind tunnel. The tunnel is equipped with a two-meter throat diameter and a 310 kph velocity potential.
Date: December 1939
Creator: Pittoni, Mario
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Contribution to the Aerodynamics of Rotating-Wing Aircraft

Description: "The chief defect of the investigations up to now was the assumption of a more or less arbitrary "mean" drag coefficient for a section of the blade. This defect is remedied through replacement of the constant coefficient by a function of higher order which corresponds to the polar curve of the employed profile. In that way it is possible to extend the theory to include the entire range from "autogyro" without power input to the driven "helicopter" with forward-tilted rotor axis. The treatment i… more
Date: December 1939
Creator: Sissingh, G.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Modern Methods of Testing

Description: After a brief survey of the commonly used single-value test methods, the importance of the determination of the incipient knock for the octane number is discussed and improvements suggested for the knock testing in the CFR engine. The DVL supercharge test method with its superiority of direct determination of fuel knock in each single cylinder of an airplane engine without involving structural changes, is described and the advantages of a multiple-value method enumerated. A diagrammatic present… more
Date: December 1939
Creator: Seeber, F.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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The Effect of Compressibility on the Pressure Reading of a Prandtl Pitot Tube at Subsonic Flow Velocity

Description: Errors arising from yawed flow were also determined up to 20 degrees angle of attack. In axial flow, the Prandtl pitot tube begins at w/a approx. = 0.8 to give an incorrect static pressure reading, while it records the tank pressure correctly, as anticipated, up to sonic velocity. Owing to the compressibility of the air, the Prandtl pitot tube manifests compression shocks when the air speed approaches velocity of sound. This affects the pressure reading of the instrument. Because of the increas… more
Date: November 1939
Creator: Walchner, O.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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The effect of the slipstream on an airplane wing

Description: The conditions which must be met at the slipstream boundary are developed, after which it is shown with the aid of the reflection method how these limiting conditions may be complied with in the case of an airfoil in a propeller slipstream in horizontal flow as well as for the propeller in yaw and with allowance for the slipstream rotation. In connection herewith, it is shown how the effective angles of attack and the circulation distribution with due regard to slipstream effect can be predicte… more
Date: November 1939
Creator: Franke, A. & Weinig, F.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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The Enlarged N.A.C.A. Tank, and Some of Its Work

Description: The most conspicuous of the features of the enlarged N.A.C.A. tank are derived directly from those of the original tank and owe their present form not only to the reasons for their first use but also to the experience obtained with them. As in the original tank, there are: 1) A basin of great length (new 2,880 feet); 2) Rails made of structural H beams, without machining; 3) A towing carriage of very high speed (now 80 mph maximum); 4) Rubber tires on all the wheels, pneumatic on the running wh… more
Date: November 1939
Creator: Truscott, Starr
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Report on Ice Formation on Aircraft

Description: The physical phenomena involved in the icing of aircraft have been analyzed and measured. Recommendations on warning devices are made as well as the different types of ice and glazing that can occur on airplanes are examined and discussed.
Date: November 1939
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Activation of hydrocarbons and the octane number

Description: This report presents an examination of the history of research on engine knocking and the various types of fuels used in the investigations of this phenomenon. According to this report, the spontaneous ignition of hydrocarbons doped with oxygen follows the logarithmic law within a certain temperature range, but not above 920 degrees K. Having extended the scope of investigations to prove hydrocarbons, the curves of the mixtures burned by air should then be established by progressive replacement… more
Date: October 1939
Creator: Peschard, Marcel
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Engine Knock and Combustion Chamber Form

Description: The present report is confined to the effect of the combustion chamber shape on engine knock from three angles, namely: 1) The uniformity of flame-front movement as affected by chamber design and position of the spark plug; 2) The speed of advance of the flame as affected by turbulence and vibrations; 3) The reaction processes in the residual charge as affected by the walls.
Date: October 1939
Creator: Zinner, Karl
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Experimental and Analytical Investigation of a Monocoque Wing Model Loaded in Bending

Description: "Bending tests with transverse loads and with pure bending were undertaken on a double-web monocoque wing model in order to establish the relation between the state of stress and the results from the elementary bending theory. The longitudinal stresses in the stiffeners were measured with tensiometers and the shear stresses in the sheet were calculated from them. The measurements were made at both moderate loads with no buckles in the covering and at loads with which the critical stress in the … more
Date: October 1939
Creator: Schapitz, E.; Feller, H. & Köller, H.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Increase of the Specific Load Under Tension, Compression, and Buckling of Welded Steel Tubes in Airplane Construction by Suitable Treatment of Structural Steel and by Proper Design

Description: Report presenting some considerations and test results that may lead to higher tension, compression, and buckling stresses than is possible with the welded-steel-tube struts of the usual familiar construction. The new construction method makes possible a considerably better material utilization and hence a saving in weight.
Date: October 1939
Creator: Müller, J.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Dynamic Stability of a Helicopter With Hinged Rotor Blades

Description: "The present report is a study of the dynamic stability of a helicopter with hinged rotor blades under hovering conditions. While in this case perfect stability can in general not be obtained it is possible by means of design features to prolong the period of the spontaneous oscillations of the helicopter and reduce their amplification, and so approximately assure neutral equilibrium. The possibility of controlled stability of a helicopter fitted with hinged blades is proved by the successful f… more
Date: September 1939
Creator: Hohenemser, K.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Knocking in the Otto-Cycle Engine

Description: Engine knock is, as is known, preceded by normal burning of the first part of the charge, and only the part burned last (residual charge), knocks. The aim of the present measurements was, first, to reexamine the combustion form in this residual charge, because of the absence of uniform and frequently contradictory results in the very extensive literature on the subject. On top of that, an attempt was to be made to gain a deeper insight into the mechanism accompanying the combustion process, by … more
Date: September 1939
Creator: Weinhart, H.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Measurements on a Low-Wing Model in the Rotating Jet and Comparison With Flight Measurements

Description: The present report deals with six-component measurements in the small tunnel of the DVL on a model of the BFW-M 27b(sub 1), which were made to determine the effect of rolling and yawing on the air forces and moments. The wind was given a spiral motion by means of a rotating screen, the model being suspended in the conventional manner. The lack of accuracy in the measurement of the rolling-yawing moments was very noticeable.
Date: September 1939
Creator: Bader, W.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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The Theory of Contra-Vanes Applied to the Propeller

Description: "The optimum circulation distribution and hence the maximum theoretical thrust obtainable for contra-vanes fitted behind propellers is markedly dependent on the number of guide vanes. The outer portion of the vanes, even if projecting considerably beyond the edge of the propeller slipstream, still contribute appreciably to this theoretical gain of thrust. But, owing to the always existing friction of the vanes, the limit of the optimum vane length lies at relatively small diameters" (p. 1).
Date: September 1939
Creator: Betz, Albert
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Two-Stroke-Cycle Engines With Unsymmetrical Control Diagram (Supercharged Engines)

Description: As no investigation of supercharging in 2-stroke-cycle engines has been published up to the present, this article is an attempt in that direction, with a view to establishing the mathematical principles and the constructive rules for the design of such engines.
Date: September 1939
Creator: Zeman, J.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Effect of Transition in Cross-Sectional Shape on the Development of the Velocity and Pressure Distribution of Turbulent Flow in Pipes

Description: With regard to the change in shape of the cross section while the area remains constant, no investigation results are as yet available. Such an investigation will be the subject of the present paper. For this purpose it is necessary to consider the velocity and pressure relations over each entire cross section so that we are confronted with a three-dimensional problem.
Date: August 1939
Creator: Mayer, Edwin
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Forces and Moments on a Yawed Airfoil

Description: "The author elaborates on the flow phenomena, forces and moments on airfoils in yaw. The existing experiments with straight wings (zero dihedral), wings with dihedral, and wings with sweepback are evaluated within the range of sound angles of attack, explained by calculation and generally enlarged" (p. 1).
Date: August 1939
Creator: Hoerner, Sighard
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Stability of Rectangular Plates With Longitudinal or Transverse Stiffeners Under Uniform Compression

Description: In the present paper, the complete buckling conditions of stiffened plates are being developed for uniform compression. We shall treat plates with one or two longitudinal or transverse stiffeners at any point, discuss the buckling conditions, and evaluate them for different cases.
Date: August 1939
Creator: Barbré, R.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Temperature-Indicating Paints

Description: This report is an attempt at a new method of coating the surface of the cylinder with materials that undergo chemical change at definite temperatures as indicated by a change in color. In this way it was hoped that the substance itself would indicate directly the position of its isotherms, which in measurements with thermocouples requires a tedious amount of labor.
Date: August 1939
Creator: Penzig, F.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Design of Centrifugal Impeller Blades

Description: This paper restricts itself to radial impellers with cylindrical blades since, as Prasil has shown, the flow about an arbitrarily curved surface of revolution may be reduced to this normal form we have chosen by a relatively simple conformal transformation. This method starts from the simple hypotheses of the older centrifugal impeller theory by first assuming an impeller with an infinite number of blades. How the flow is then modified is then investigated.
Date: July 1939
Creator: Betz, A. & Flügge-Lotz, I.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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The Effect of the Masses of the Controls on the Longitudinal Stability With Free Elevator Part 1

Description: In the present report, aerodynamic relations under the effect of the weight moments are investigated, and an example given of the computation of the stability for a practical case. Later, the effects of the masses of the controls on the dynamic longitudinal stability will be considered.
Date: July 1939
Creator: Schmidt, Rudolf
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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