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Analysis of Spinning in a Monoplane Wing by the Induction Method as Compared With the Strip Method

Description: The problem of autorotation has been attacked by various authors, in particular Fuchs and Schmidt who applied the so-called strip method which is based upon the assumption that the forces and moments per unit length acting in each section of the wing are equal to those on an infinite cylindrical wing of equal section in an air flow of intensity and direction resulting from the apparent relative motion of this section with respect to the surrounding air. In other words they disregarded the induced velocities, which, however, are of such importance that their omission is bound to result in appreciable errors, as we attempt to prove in this report.
Date: June 1934
Creator: Poggi, L.
Partner: UNT Libraries Government Documents Department

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

Air Transport by Gliders: Some Technical Observations

Description: This short analysis may be useful in determining the real tactical possibilities of "glider trains" and in adopting the course to be followed in possible studies of these questions. In this analysis most prominent are: (a) the power required for the train in level flight; (b) its speed; (c) climb; and (d) the type of airplane best suited for towing as well as design requirements for transport gliders.
Date: June 1941
Creator: Stepniewski, Wieslaw
Partner: UNT Libraries Government Documents Department

Tests for the Elimination of Tail Flutter

Description: "On various low-wing monoplanes the horizontal tail surfaces flutter in flight at large angles of attack and occasionally in curvilinear flight. This flutter leads to torsional vibrations of the rear end of the fuselage, as manifested by vibrations of the control stick. According to the earlier DVL investigations tail flutter is due to the influence, on horizontal tail surfaces, of eddies or vortices shed at large angles of attack by the upper surface of the wing root. The cause of tail flutter on a low-wing monoplane and the means of preventing it are investigated in the present report" (p. 1).
Date: June 1933
Creator: Biechteler, Curt
Partner: UNT Libraries Government Documents Department

A Simple Method for Increasing the Lift of Airplane Wings by Means of Flaps

Description: "Aerodynamic considerations led us, not long ago, to investigate a device which seemed to promise a contribution to the problem of reducing the landing speed of an airplane. We have subsequently learned that similar devices had already been proposed and investigated by others, but it seems advisable, nevertheless, to report our results. The problem is to create, in landing, a region of turbulence on the lower side of the wing near the trailing edge by some obstacle to the air flow" (p. 1).
Date: June 1933
Creator: Gruschwitz, Eugen & Schrenk, Oskar
Partner: UNT Libraries Government Documents Department

Theoretical Study of Various Airplane Motions After Initial Disturbance

Description: The present investigation may be considered as preliminary to the study of automatic stabilizers. We have sought to determine first how an airplane of average characteristics reacts against the principal disturbances it may encounter. Without entering into the general study of automatic stabilizers, the present work suggests the idea of a stabilizer whose sensitive member would be a wind vane or pressure plate.
Date: June 1938
Creator: Haus
Partner: UNT Libraries Government Documents Department

Method of Curved Models and Its Application to the Study of Curvilinear Flight of Airships: Part 2

Description: This report compares the results obtained by the aid of curved models with the results of tests made by the method of damped oscillations, and with flight tests. Consequently we shall be able to judge which method of testing in the tunnel produces results that are in closer agreement with flight test results.
Date: June 1937
Creator: Gourjienko, G. A.
Partner: UNT Libraries Government Documents Department

The "Navigraph"

Description: "Commander Le Prieur, whose flight experience in a low-speed seaplane we related in our number of September 27, 1924, invented, four years ago, an instrument destined to render very great service to aviators, namely, the "navigraph", designed to correct errors of orientation due to the effect of the winds during flight" (p. 1).
Date: June 1925
Creator: Le Prieur, Ives
Partner: UNT Libraries Government Documents Department

Impact Buckling of Thin Bars in the Elastic Range Hinged at Both Ends

Description: "Following the development of the well-known differential equations of the problem and their resolution for failure in tension, the bending (transverse) oscillations of an originally not quite straight bar hinged at both ends and subjected to a constant longitudinal force (shock load) are analyzed. To this end the course of the bar form is expanded in a sinusoidal series, after which the investigation is carried through separately for the fundamental oscillation and the (n-1)the higher oscillations. The analysis of the fundamental oscillation distinguishes three cases: shock load lower, equal to, or higher than the Eulerian load" (p. 1).
Date: June 1934
Creator: Koning, Carel & Taub, Josef
Partner: UNT Libraries Government Documents Department

Ignition Process in Diesel Engines

Description: This report analyzes the heating and vaporization process of fuel droplets in a compression-ignition engine on the basis of the theory of similitude - according to which, the period for heating and complete vaporization of the average size fuel drop is only a fraction of the actually observed ignition lag. The result is that ignition takes place in the fuel vapor air mixture rather than on the surface of the drop. The theoretical result is in accord with the experimental observations by Rothrock and Waldron. The combustion shock occurring at lower terminal compression temperature, especially in the combustion of coal-tar oil, is attributable to a simultaneous igniting of a larger fuel-vapor volume formed prior to ignition.
Date: June 1936
Creator: Wentzel, W.
Partner: UNT Libraries Government Documents Department

Investigation of a Wing With an Auxiliary Upper Part

Description: This report presents experiments in which two parts of the wing were arranged so as to form a biplane, which was subjected to normal three-component measurements, the two parts being placed in various relative positions with respect to the gap a and the stagger b.
Date: June 1927
Creator: Seiferth, R.
Partner: UNT Libraries Government Documents Department

A Method for the Instantaneous Determination of the Velocity and Direction of the Wind

Description: The laboratory instruments, which we often constructed with makeshift means, gave encouraging results and showed that they could satisfactorily meet the required conditions. By limiting ourselves to the employment of hot wires of 0.05 mm (0.002 in.) diameter, we obtained instruments which faithfully followed all the wind fluctuations of over 0.1 second and even much more rapid variations without any very great error.
Date: June 1924
Creator: Huguenard, E.; Magnan, A. & Planiol, A.
Partner: UNT Libraries Government Documents Department

Method of Curved Models and Its Application to the Study of Curvilinear Flight of Airships: Part 1

Description: In the first part of this paper we shall present the theoretical side of the problem of constructing curved model forms and the method of testing the model. In the second part we shall present a detailed account of the first experiments according to the given method, carried out with a curved model of the nonrigid airship V-2, and a comparison of the experimental results with some data of full-scale tests made with this airship in 1933.
Date: June 1937
Creator: Gourjienko, G. A.
Partner: UNT Libraries Government Documents Department

Landing Impact of Seaplanes

Description: The theory of landing impact is briefly stated and the applicability of a previously suggested formula is extended. Theoretical considerations regarding impact measurements on models and actual seaplanes are followed by a brief description of the instruments used in actual flight tests. The report contains a description of the strength conditions and deals exhaustively with force measurements on the float gear of an "HE 9a" with flat-bottom and with V-bottom floats. The experimental data are given and compared with the theoretical results.
Date: June 1931
Creator: Pabst, Wilhelm
Partner: UNT Libraries Government Documents Department

The World's Air Transportation Services: Data as to Passengers, Mail, and Goods Carried by American and European Transportation Services

Description: This report presents detailed descriptions, statistics, and graphs on European and American air transport. The European countries listed are Belgium, Czecho-Slovakia, Denmark, France, Germany, Great Britain, Holland, and Italy.
Date: June 1922
Creator: Office of Aeronautical Intelligence
Partner: UNT Libraries Government Documents Department

The R-38 Catastrophe and the Mechanics of Rigid Airship Construction

Description: An airship frame may be regarded as a rigid girder subjected to a number of forces which, according to their nature, may be classified as follows: weight or loads (force of gravity); lifting forces (aero-static); accelerations (dynamic). These forces must be in equilibrium in the three most important cases during flight: 1) when the airship is floating (aerostatic problem); 2) when flying without acceleration (aerodynamic problem). 3) When under the influence of any accelerating force (dynamic problem). This report will briefly discuss each of these cases in regard to the R-38 airship accident.
Date: June 1922
Creator: Herrera, Emilio
Partner: UNT Libraries Government Documents Department

Effect of Structure in Middle Part of Leading Edge of a Thick Wing: Communication From Rijks-Studiedienst Voor De Luchtvaart of Amsterdam

Description: The experiments herein described were made for the purpose of finding whether removing a larger portion of the wing to improve the pilot's view would be possible, without too great detriment to the aerodynamic properties of the airplane. The experiments were conducted on a wing similar to the Fokker F III.
Date: June 1922
Partner: UNT Libraries Government Documents Department

Engine Pistons of Light Metal

Description: This report presents the results of testing 32 sets of light metal pistons from 16 different aluminum and magnesium alloys, 2 sets of cast iron pistons, and one piston of pure electrolytic copper. The many-fold mutual relations between material properties, shape, thermic and dynamic processes in the engine were clarified by comprehensive technical, thermic, chemical, physical and metallographic investigations of pistons and piston materials.
Date: June 1922
Creator: Becker, G.
Partner: UNT Libraries Government Documents Department

Fakir Fuel Pump

Description: "In designing the Fakir fuel pump, the fundamental idea was to obtain a simple and reliable method of conveying the fuel from a low tank to the carburetor, with the avoidance of the faults of all former methods and the simultaneous warming of the fuel by means of the heat of compression generated. The principle of the Fakir fuel pump rests on the well-known principle of the diaphragm pump, which must be suitably adapted to the present purpose" (p. 1).
Date: June 1922
Partner: UNT Libraries Government Documents Department

Report on Commercial Air Transportation Activities in England, France, Germany and Holland

Description: The following pages present a review of the air transportation activities of England, France, Germany and Holland, based on an inspection trip during the summer of 1924. The different components described include operating companies, nature of transportation services, air traffic, flying equipment, government relations, and general remarks.
Date: June 1925
Creator: Van Zandt, J. Parker
Partner: UNT Libraries Government Documents Department

On the Symmetrical Potential Flow of Compressible Fluid Past a Circular Cylinder in the Tunnel in the Subcritical Zone

Description: "The two-dimensional symmetrical potential flow of compressible fluid past a circular cylinder placed in the center line of a straight tunnel is analyzed in second approximation according to the Jansen-Rayleigh method. The departure of the profile from the exact circular shape can be kept to the same magnitude as for the incompressible flow. The velocities in the narrowest section of the tunnel wall and at the profile edge are discussed in detail" (p. 1).
Date: June 1942
Creator: Lamla, Ernst
Partner: UNT Libraries Government Documents Department

Problem of the Slotted Wing: A Communication From the Aerodynamic Institute of the Aachen Technical High School

Description: "It is to be expected that the advantageous properties, hitherto discovered in many slotted wing sections, depend very largely on the contour of the slot and the structural details of the wing. It is therefore of interest, aside from measurements on wings of constant cross-section along the span, to measure also wing models in which the structural details have already been given practical consideration" (p. 1).
Date: June 1922
Creator: Klemperer, W.
Partner: UNT Libraries Government Documents Department

On the Theory of Combustion of Initially Unmixed Gases

Description: The chemical reaction of two substances (fuel and oxygen) accompanied by the formation of new substances of the products of combustion and the liberation of heat is considered. General equations are provided as well as an analysis of the equation and the distribution of products of the reaction.
Date: June 1951
Creator: Zeldovich, Y. B.
Partner: UNT Libraries Government Documents Department

Replacing the Weight of Materials Consumed on Airships

Description: Two methods to replace the weight of gas lost on long airship flights are discussed: condensing the water of combustion and thermic sustentation. In the present article we will discuss the first method, leaving the second to be examined in a subsequent article.
Date: June 1923
Creator: Crocco, G. A.
Partner: UNT Libraries Government Documents Department