Technical Report Archive & Image Library (TRAIL) - 32 Matching Results

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Meteorological-Physical Limitations of Icing in the Atmosphere

Description: The icing hazard can, in most cases, be avoided by correct execution of the flights according to meteorological viewpoints and by meteorologically correct navigation (horizontal and, above all, vertical). The zones of icing hazard are usually narrowly confined. Their location can be ascertained with, in most cases, sufficient accuracy before take-off.
Date: January 1939
Creator: Findeisen, W.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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The Small Wind Tunnel of the DVL

Description: A general description of the small DVL wind tunnel is provided, with emphasis on air conduction, blower and velocity regulation, velocity measurement, and balance and model suspension.
Date: January 1934
Creator: Seewald, Friedrich
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Aerodynamic principles of the direct lifting propeller

Description: From Summary: "The purpose of this report is to make the complicated processes on the direct-lift propeller amenable to analysis and observation. This is accomplished by placing the physical phenomena, starting with the most elementary process, in the foreground, while limiting the mathematical treatment to the most essential in view of the fundamental defects of the theorems. Comparison with model experiments supplements and corroborates the theoretical results."
Date: January 1934
Creator: Schrenk, Martin
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Evaluation of Scavenging in Two-Stroke-Cycle Engines

Description: The viewpoints are discussed, according to which the scavenging of two-stroke-cycle engines can be evaluated, and the relations between scavenging pressure and the quantity of the scavenging medium required, as also between the scavenging pressure and the revolution speed, are developed. It is further shown that the power increase is limited by the scavenging process, so that further researches are desirable for qualitative improvement. These results lead to several conclusions regarding the pr… more
Date: January 1934
Creator: Venediger, Herbert J.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Status of Wing Flutter

Description: "This report presents a survey of previous theoretical and experimental investigations on wing flutter covering thirteen cases of flutter observed on airplanes. The direct cause of flutter is, in the majority of cases, attributable to (mass-) unbalanced ailerons. Under the conservative assumption that the flutter with the phase angle most favorable for excitation occurs only in two degrees of freedom, the lowest critical speed can be estimated from the data obtained on the oscillation bench" (p… more
Date: January 1936
Creator: Küssner, H. G.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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The Heat Transfer of Cooling Fins on Moving Air

Description: The present report is a comparison of the experimentally defined temperature and heat output of cooling fins in the air stream with theory. The agreement is close on the basis of a mean coefficient of heat transfer with respect to the total surface. A relationship is established between the mean coefficient of heat transfer, the dimensions of the fin arrangement, and the air velocity.
Date: January 1935
Creator: Doetsch, Hans
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Effect of aerodynamic design on glider performance

Description: The performance of a glider is determined by means of the velocity polar, which represents the connection between horizontal and sinking speed. The mean sinking speed for a given speed range can be determined on the basis of the velocity polar. These data form the basis for the most propitious design of a performance-type glider with a view to long-distance flight.
Date: January 1935
Creator: Lippisch, A.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Gliding in Convection Currents

Description: "A survey of the possibilities of gliding in convection currents reveals that heretofore only the most simple kind of ascending convection currents, that is, the "thermic" of insolation, has been utilized to any extent. With the increasing experience in gliding, the utilization of the peculiar nature of the "wind thermic" and increased glider speed promises further advances. Evening, ocean, and height "thermic" are still in the exploration stage, and therefore not amenable to survey in their ef… more
Date: January 1935
Creator: Georgii, W.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Dynamic Breaking Tests of Airplane Parts

Description: "The static stresses of airplane parts, the magnitude of which can be determined with the aid of static load assumptions, are mostly superposed by dynamic stresses, the magnitude of which has been but little explored. The object of the present investigation is to show how the strength of airplane parts can best be tested with respect to dynamic stresses with and without superposed static loading, and to what extent the dynamic strength of the parts depends on their structural design. Experiment… more
Date: January 1933
Creator: Hertel, Heinrich
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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The D.V.L. Gliding-Angle Control (W. Hübner Design)

Description: This report describes a device for arbitrary enlargement of the gliding angle of airplanes, especially of such with flat gliding angle and difficult landing characteristics. The D.V.L. gliding angle control (design, Hubner) permits a local interruption of the lift distribution along the span and consequently an increased induced drag. The mechanism comprises two wing rudders operated by lever from the pilot's cockpit. Said rudders are fitted on the top side of the wing near the leading edge. Th… more
Date: January 1933
Creator: Hübner, Walter & Pleines, Wilhelm
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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The Problem of the Propeller in Yaw With Special Reference to Airplane Stability

Description: The quantity of air which the disk area described by propeller blades travels through, is accelerated rearward conformably to the momentum of the forces acting on the propeller. The accelerated air mass forms behind the propeller the so-called slipstream, in which among others, the mean velocity of advance is increased. If the propeller axis slopes toward the relative flight direction, the slipstream direction likewise changes, i.e., it sets up a downwash behind the propeller.
Date: January 1933
Creator: Misztal, Franz
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Theory of Two-Dimensional Potential Flow About Arbitrary Wing Sections

Description: "Three general theories treating the potential flow about an arbitrary wing section are discussed in this report. The first theory treats the method of conformal transformation as laid down by Theodorsen and Garrick; the second is a generalization of Birnbaum's theory for moderately thick airfoils; the third is a general investigation of the complex velocity function with particular reference to the relations first discussed by F. Weinig. The relative merits of the different methods in question… more
Date: January 1939
Creator: Gebelein, H.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Wrinkling of Reinforced Plates Subjected to Shear Stresses

Description: An analysis is made here of the problem of long plates with transverse stiffeners subject to shear. A typical example would be a long Wagner beam. The shear stress is calculated at which the web wrinkles and shear stress becomes a maximum. The equation is solved for both a condition of free support and rigidity of support on the edges.
Date: January 1931
Creator: Seydel, Edgar
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Wrinkling Phenomena of Thin Flat Plates Subjected to Shear Stresses

Description: This report covers a series of tests on thin flat elastic strips restrained at two parallel edges and subjected to shear by conversely directed stresses. Theoretical treatments, particularly those of Lilly, Southwell and Skan, and Timoshenko are briefly outlined. The problem to be solved by these tests was to find out whether, and to what extent the conditions and assumptions upon which the calculations are based are complied with in the tests.
Date: January 1931
Creator: Bollenrath, F.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Stresses Produced in Airplane Wings by Gusts

Description: Accurate prediction of gust stress being out of the question because of the multiplicity of the free air movements, the exploration of gust stress is restricted to static method which must be based upon: 1) stress measurements in free flight; 2) check of design specifications of approved type airplanes. With these empirical data the stress must be compared which can be computed for a gust of known intensity and structure. This "maximum gust" then must be so defined as to cover the whole ambit o… more
Date: January 1932
Creator: Küssner, Hans Georg
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Stresses in Reinforcing Rings Due to Axial Forces in Cylindrical and Conical Stressed Skins

Description: "At the ends of a monocoque fuselage concentrated axial forces in the skin must generally be taken up. Such axial forces must also be taken up in the case of other members where axial forces from the neighboring stressed skin construction must be considered. In order to take up these axial forces two bulkheads or reinforcing frames may be arranged at the positions where the forces are applied" (p. 1).
Date: January 1938
Creator: Drescher, K. & Gropler, H.
Item Type: Refine your search to only Report
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.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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The Gyroplane: Its Principles and Its Possibilities

Description: This report begins by indicating several simple principles concerning the velocity distribution over the blades of a lifting propeller of diameter D, revolving at n revolutions per second, and animated by a horizontal movement of translation at speed V. The calculation, compared with the test data, has shown that the aerodynamic action of the air on the blades depends almost only on the velocity components in a plane at right angles to the blade span. A history of gyroplane and gyrocopter devel… more
Date: January 1937
Creator: Breguet, Louis
Item Type: Refine your search to only Report
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.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Torsion and buckling of open sections

Description: Following an abstract of the well-known theory of torsion in compression, the writers give directions for the practical calculation of the values of C(sub BT) (resistance to flexure and torsion) and i(sub SP(exp 2)), which determine the torsion. The second part treats the experiments in support of the theory of torsion of plain and flanged angle sections.
Date: January 1936
Creator: Wagner, H. & Pretschner, W.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Calculation of the Induced Efficiency of Heavily Loaded Propellers Having Infinite Number of Blades

Description: Report presenting an approximate method of computing the induced efficiency of heavily loaded propellers in suitable form for extension to finite number of blades and a comparison of results obtained using the method with the data of the Betz-Helmbold theory for heavily loaded propellers.
Date: January 1939
Creator: Lösch, F.; Kramer, K. N.; Bock, G. & Nikodemus, R.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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