UNT Libraries Government Documents Department - 43 Matching Results

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Accurate calculation of multispar cantilever and semicantilever wings with parallel webs under direct and indirect loading

Description: In the present report the computation is actually carried through for the case of parallel spars of equal resistance in bending without direct loading, including plotting of the influence lines; for other cases the method of calculation is explained. The development of large size airplanes can be speeded up by accurate methods of calculation such as this.
Date: March 1932
Creator: Sanger, Eugen

Airplane Flight in the Stratosphere

Description: This brief survey of the problems encountered in high-altitude flight deals in particular with the need for high lift coefficient in the wings, large aspect ratios in the wings, and also the problem of hermetically sealing the cabin.
Date: February 1932
Creator: de Caria, Ugo

Airplane Stability in Taxying

Description: The stability analysis of an airplane while rolling is much more simplified to the extent that it can be obtained for numerical data which can be put to practical use in the design of landing gear dimensions. Every landing gear type attains to a critical ground friction coefficient that decides the beginning of instability, i.e., nosing over. This study has, in addition, a certain interest for the use of wheel brakes.
Date: September 1932
Creator: Anderlik, E.

Application of the theory of free jets

Description: Based upon Kirchoff's theory of free jets the flow through different screen arrangements of flat plates, as chiefly encountered with turbines in the cavitation zone is defined. It is shown by experiments that these theoretical results are very well representative in most cases of the conditions of discharge from water in air and consequently by cavitation. In addition, the experiments reveal a picture of the discrepancies between the actual flow and the theory of discharge of air in air (of water in water without cavitation). These discrepancies are explained qualitatively by the mingling processes between the jets and the dead air zones.
Date: April 1932
Creator: Betz, A. & Petersohn, E.

Approximate calculation of multispar cantilever and semicantilever wings with parallel ribs under direct and indirect loading

Description: A method is presented for approximate static calculation, which is based on the customary assumption of rigid ribs, while taking into account the systematic errors in the calculation results due to this arbitrary assumption. The procedure is given in greater detail for semicantilever and cantilever wings with polygonal spar plan form and for wings under direct loading only. The last example illustrates the advantages of the use of influence lines for such wing structures and their practical interpretation.
Date: August 1932
Creator: Sanger, Eugen

Automatic stability of airplanes

Description: It is endeavored in this report to give a full outline of the problem of airplane stability and to classify the proposed solutions systematically. Longitudinal stability, which can be studied separately, is considered first. The combination of lateral and directional stabilities, which cannot be separated, will be dealt with later.
Date: December 1932
Creator: Haus, FR

Calculation of potential flow past airship bodies in yaw

Description: An outline of Von Karman's method of computing the potential flow of airships in yaw by means of partially constant dipolar superposition on the axis of the body is followed by several considerations for beginning and end of the superposition. Then this method is improved by postulating a continuous, in part linearly variable dipolar superposition on the axis. The second main part of the report brings the calculation of the potential flow by means of sources and sinks, arranged on the surface of the airship body. The integral equation which must satisfy this surface superposition is posed, and the core reduced to functions developed from whole elliptical normal integrals. The functions are shown diagrammatically. The integration is resolvable by iteration. The consequence of the method is good. The formulas for computing the velocity on the surface and of the potential for any point conclude the report.
Date: July 1, 1932
Creator: Lotz, I

Combustion of Gaseous Mixtures

Description: This report not only presents matters of practical importance in the classification of engine fuels, for which other means have proved inadequate, but also makes a few suggestions. It confirms the results of Withrow and Boyd which localize the explosive wave in the last portions of the mixture burned. This being the case, it may be assumed that the greater the normal combustion, the less the energy developed in the explosive form. In order to combat the detonation, it is therefore necessary to try to render the normal combustion swift and complete, as produced in carbureted mixtures containing benzene (benzol), in which the flame propagation, beginning at the spark, yields a progressive and pronounced darkening on the photographic film.
Date: November 1932
Creator: Duchene, R.

Combustion Velocity of Benzine-Benzol-Air Mixtures in High-Speed Internal-Combustion Engines

Description: "The present paper describes a device whereby rapid flame movement within an internal-combustion engine cylinder may be recorded and determined. By the aid of a simple cylindrical contact and an oscillograph the rate of combustion within the cylinder of an airplane engine during its normal operation may be measured for gas intake velocities of from 30 to 35 m/s and for velocities within the cylinder of from 20 to 25 m/s. With it the influence of mixture ratios, of turbulence, of compression ratio and kind of fuel on combustion velocity may be determined" (p. 1).
Date: April 1932
Creator: Schnauffer, Kurt

The controls at low hinge moments

Description: A very stable airplane remains very maneuverable when the hinge moments of the controls remain inferior to those obtained with the conventional forms and when the wing lift at high angles has been improved. From this point of view, elevators balanced by recoil of the hinge, and slotted wings present some interesting features.
Date: September 1, 1932
Creator: Pris, M

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

Disintegration of a liquid jet

Description: This report presents an experimental determination of the process of disintegration and atomization in its simplest form, and the influence of the physical properties of the liquid to be atomized on the disintegration of the jet. Particular attention was paid to the investigation of the process of atomization.
Date: February 1, 1932
Creator: Haenlein, A

Dynamic testing of airplane shock-absorbing struts

Description: Measurement of perpendicular impacts of a landing gear with different shock-absorbing struts against the drum testing stand. Tests were made with pneumatic shock absorbers having various degrees of damping, liquid shock absorbers, steel-spring shock absorbers and rigid struts. Falling tests and rolling tests. Maximum impact and gradual reduction of the impacts in number and time in the falling tests. Maximum impact and number of weaker impacts in rolling tests.
Date: January 1932
Creator: Thome, W & Langer, P

Effect of the ground on an airplane flying close to it

Description: In America and England the ground effect has received much attention for a long time, and whole series of model and flight tests have been made, which have, however, been chiefly devoted to changes in the induced drag. The experiments here described show that the increase in lift may be of high enough order of magnitude to be taken into account also.
Date: June 1, 1932
Creator: Tonnies, E

Experimental determination of the thickness of the boundary layer along a wing section

Description: The thickness and course of the boundary layer were measured in flight, in order to determine whether the relations on an airplane and on a shop-made wing can be brought into agreement with the results of wind-tunnel tests and Horst Muller's calculations of the thickness of the boundary layer, as developed from Karman's integral equation for the boundary layer.
Date: August 1, 1932
Creator: Cuno, Otto

Experiments with planing surfaces

Description: Experiments with planing surfaces are fundamental, hydrodynamic researches for the purpose of obtaining the most favorable forms for planing boats, flying boats, and seaplane floats, with respect to water resistance and seaworthiness.
Date: March 1932
Creator: Sottorf, W.

Further Flight Tests on the Effectiveness of Handley Page Automatic Control Slots

Description: Investigation of damping in roll within range of maximum lift with the Albatross L 75, with and without Handley Page automatic control slots, revealed the following: Without control slots, any attempt to go beyond a certain angle of attack near c(sub a max) in glide and climb, is followed by sudden sideslip. The conduct of the airplane throughout the motions in roll, moreover, confirmed that all attempts to higher angles of attack are accompanied by sudden loss of damping in roll.
Date: September 1932
Creator: Pleines, Wilhelm

German aircraft accident statistics, 1930

Description: The investigation of all serious accidents, involving technical defects in the airplane or engine, is undertaken by the D.V.L. in conjunction with the imperial traffic minister and other interested parties. All accidents not clearly explained in the reports are subsequently cleared up.
Date: March 1932
Creator: Weitzmann, Ludwig

Increase in the maximum lift of an airplane wing due to a sudden increase in its effective angle of attack resulting from a gust

Description: Wind-tunnel tests are described, in which the angle of attack of a wing model was suddenly increased (producing the effect of a vertical gust) and the resulting forces were measured. It was found that the maximum lift coefficient increases in proportion to the rate of increase in the angle of attack. This fact is important for the determination of the gust stresses of airplanes with low wing loading. The results of the calculation of the corrective factor are given for a high-performance glider and a light sport plane of conventional type.
Date: July 1, 1932
Creator: Kramer, Max