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Manganese: Its Occurrence, Milling, and Metallurgy; Part 1

Description: Report issued by the U.S. Bureau of Mines discussing the "occurrence, milling, and metallurgy of manganese in the United States" (p. 1). Different properties and compounds of manganese are also discussed. This report includes a map, tables, illustrations, and photographs.
Date: May 1934
Creator: Dean, Reginald S.; DeVaney, Fred D. & Coghill, Will H.
Partner: UNT Libraries Government Documents Department

The Source of Propeller Noise

Description: A two blade propeller of 40 cm diameter and zero pitch was explored for its noise development; it could be whirled up to 17,000 rpm - i.e., a tip speed of 355 meters/second. To obtain the power loss N(sub m) of the propeller for comparison with the produced acoustical power N(sub A) the engine performance characteristics were measured with and without propeller. The result is the sought-for relation c, that is, curve c' after correction with the engine efficiency.
Date: May 1937
Creator: Ernsthausen, W.
Partner: UNT Libraries Government Documents Department

The Short "Scylla" Commercial Airplane (British): An All-Metal Biplane

Description: Circular presenting a description of the Short Scylla, which is a 39-passenger landplane with four Bristol Jupiter XF BM engines. A description of the characteristics, blueprints, and photographs of the aircraft are provided.
Date: May 1934
Partner: UNT Libraries Government Documents Department

Similitude in Hydrodynamic Tests Involving Planing

Description: The problems of using models in planing tests are addressed. If one passes from the model to a hull of linear dimensions n times greater, the speeds are connected by the law of mechanical similitude. The normal forces given by the hydrodynamic equations (perfect fluid) also follow the law of dynamic similitude (Reech's method) and are multiplied by n(exp 3). A series of tests were performed and the actual results were compared to theoretical results.
Date: May 1936
Creator: Gruson, M. F.
Partner: UNT Libraries Government Documents Department

Investigation of Full-Scale Split Trailing-Edge Wing Flaps With Various Chords and Hinge Locations

Description: This report gives the results of an investigation conducted in the NACA full-scale wind tunnel on a small parasol monoplane equipped with three different split trailing-edge wing flaps. The object of the investigation was to determine and correlate data on the characteristics of the airplane and flaps as affected by variation in flap chord, flap deflection, and flap location along the wing chord. The results give the lift, the drag, and the pitching moment characteristics of the airplane, and the flap forces and moments, the pressure distribution over the flaps and wing at one section, and the downwash characteristics of the flap and wing combinations.
Date: May 10, 1935
Creator: Wallace, Rudolf
Partner: UNT Libraries Government Documents Department

Landing of Seaplanes

Description: This report begins with a brief resume of a theoretical consideration and its results. Then a description is presented of the processes at the moment a keeled bottom strikes the water and the formulas and solutions are given. Lastly a discussion of the application of these results to practical problems is given.
Date: May 1931
Creator: Wagner, Herbert
Partner: UNT Libraries Government Documents Department

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

Future Problems of Soaring Flight: Report of 1932 Rhon Soaring Contest

Description: Memorandum presenting two reports. One is a description of the 1932 Rhön Soaring Contest and some of the problems encountered by the aircraft in the contest. The other is a description of films of cloud formations that were presented at the same contest.
Date: May 1933
Creator: Georgii, Walter & Eisenlohr, Roland
Partner: UNT Libraries Government Documents Department

Determination of Stresses and Deformations of Aircraft Propellers

Description: A method is described for testing the strength of propellers of any shape. It is shown that the shape of the propeller greatly affects the stresses, and that great caution must be exercised if the relieving effect of the centrifugal force, which exists in every propeller with a straight blade axis, is to be increased by curving the blade axis. In a numerical example, the calculation is made for a certain revolution speed at which the actual distortion is then measured. The results of the calculation agree satisfactorily with the experimental results.
Date: May 1932
Creator: Seewald, Friedrich
Partner: UNT Libraries Government Documents Department

Experiments With Needle Bearings

Description: Experiments and results are presented in testing needle bearings, especially in comparison with roller bearings. Reduction in coefficient of friction is discussed as well as experimental methods and recording devices.
Date: May 1933
Creator: Ferretti, Pericle
Partner: UNT Libraries Government Documents Department

Flame Movement and Pressure Development in an Engine Cylinder

Description: "This investigation describes a visual method for making stroboscopic observations, through a large number of small windows, of the spread of flame throughout the combustion chamber of a gasoline engine. Data, secured by this method on a small engine burning gaseous fuels, are given to show the effects of mixture ratio, spark advance, engine speed, charge density, degree of dilution, compression ratio, and fuel composition on flame movement in the cylinder. Partial indicator diagrams showing pressure development during the combustion period are included" (p. 697).
Date: May 1, 1931
Creator: Marvin, Charles F., Jr. & Best, Robert D.
Partner: UNT Libraries Government Documents Department

Flight-Test Data on the Static Fore-and-Aft Stability of Various German Airplanes

Description: "The static longitudinal stability of an airplane with locked elevator is usually determined by analysis and model tests. The present report proposes to supply the results of such measurements. The method consisted of recording the dynamic pressure versus elevator displacement at different center-of-gravity positions in unaccelerated flight" (p. 1).
Date: May 1933
Creator: Hübner, Walter
Partner: UNT Libraries Government Documents Department

Experimental Verification of the Theory of Wind-Tunnel Boundary Interference

Description: "The results of an experimental investigation on the boundary-correction factor are presented in this report. The values of the boundary-correction factor from the theory, which at the present time is virtually completed, are given in the report for all conventional types of tunnels. With the isolation of certain disturbing effects, the experimental boundary-correction factor was found to be in satisfactory agreement with the theoretically predicted values, thus verifying the soundness and sufficiency of the theoretical analysis" (p. 79).
Date: May 18, 1933
Creator: Theodorsen, Theodore & Silverstein, Abe
Partner: UNT Libraries Government Documents Department

High-Speed Aircraft

Description: This report details the designs of high-speed aircraft from various countries from 1931 on, with special emphasis on the United States and Germany.
Date: May 1934
Creator: Schrenk, M.
Partner: UNT Libraries Government Documents Department

Helicopter Problems

Description: The present report deals with a number of the main problems requiring solution in the development of helicopters and concerning the lift, flying performance, stability, and drive. A complete solution is given for the stability of the helicopter with rigid blades and control surfaces. With a view to making a direct-lift propeller sufficient without the addition of auxiliary propellers, the "flapping drive" is assessed and its efficiency calculated.
Date: May 1937
Creator: Küssner, H. G.
Partner: UNT Libraries Government Documents Department

The High-Speed Heinkel HE 70 Mail Airplane

Description: This report details the design and construction of the Heinkel 70 mailplane and its comparison with the Lockheed "Orion".
Date: May 1934
Creator: Heinkel, Ernst
Partner: UNT Libraries Government Documents Department

Balanced and Servo Control Surfaces

Description: "Many reports on various control systems are available, but the results cannot be generally applied since the effect of particular changes of surface-form and mounting are subject to variations depending upon airfoil section and influences of airplane layout. This report presents a simple analysis of several control systems in more general use. Elevators, ailerons, and rudders are all discussed" (p. 1).
Date: May 1930
Partner: UNT Libraries Government Documents Department

Twelfth Rhon Soaring Contest, 1931

Description: The crew of the "Fafnir" was given an excellent opportunity for collecting first-hand data as to the usefulness of gliders in the Alps. It is necessary to recount the remarkable glider achievements ahead of the Rhon Soaring Contest, in order to understand the tension and expectation with which the Rhon contest was anticipated. A description of some of the aircraft present at the event is provided.
Date: May 1932
Creator: Georgii, Walter
Partner: UNT Libraries Government Documents Department