UNT Libraries Government Documents Department - 29 Matching Results

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The Scale Effect in Towing Tests With Airplane-Float Systems

Description: "The present report includes a description of the making of three-component measurements on a full-size float mounted on an actual airplane and the comparison of the results with those from two models of the same form but of different size which had been tested in the towing tank. The purpose of the comparison is to determine the effect of the Reynolds Number on the results of model tank tests. Following a brief discussion of previous tests intended to elucidate the problem of scale effect on f… more
Date: May 1937
Creator: Schmidt, Rudolph
Item Type: Refine your search to only Report
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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.
Item Type: Refine your search to only Report
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Experimental investigation of the problem of surface roughness

Description: Based on the universal laws of turbulent velocity distribution at rough and smooth walls, there is in the present work presented a method that allows surface roughness tests and in particular, measurements on the roughness of ship surfaces to be carried out in a much simpler manner. The types of roughness investigated were in the form of flat, rough plates installed in a square-section rectangular channel, the other three walls always being smooth. Twenty-one plates of various roughness were in… more
Date: April 1937
Creator: Schlichting, H.
Item Type: Refine your search to only Report
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Turbulent Boundary Layer of an Airfoil

Description: A need has arisen for a new determination of the velocity profiles in the boundary layer. Assuming that the character of the velocity distribution depends to a large extent on the character of the shear distribution across the boundary layer, we shall consider the nature of the shear distribution for a boundary layer with a pressure gradient.
Date: April 1937
Creator: Fediaevsky, K.
Item Type: Refine your search to only Report
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On the Actual Loads on Airplane Landing Gears

Description: This investigation was intended to throw light on a number of problems: 1) obtain a time history of the force acting on the gear wheels during take-off and landing runs; 2) obtain the time history of the direction of this force (magnitude of its three components along the coordinate axes); 3) derive conclusions as to the design load factors. In connection with the latter, of special interest was the solution of such problems as: a) the dynamic loads in the three main landing attitudes; b) the p… more
Date: March 1937
Creator: Shiskin, S.
Item Type: Refine your search to only Report
open access

Some Experiments on the Slipstream Effect

Description: The models designated "Torino 30, 31, 32" are horizontal tail surfaces of rectangular, triangular, and elliptical plan form and all of the same profile section. Tests were carried out with the object being to determine the effect of the propeller slipstream on the aerodynamical characteristics of the horizontal stabilizer. The results presented correspond to a first series of tests made without an interposed wing and in which the distance between the plane of the propeller disk and the tail was… more
Date: March 1937
Creator: Ferrari, C.
Item Type: Refine your search to only Report
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Experimental Apparatus for the Study of Propellers

Description: The apparatus consists of a universal balance with transmission at variable speeds from 300 to 5,000 rpm and a group directly coupled to the model for speeds of 5 to 30,000 revolutions. This new apparatus was also designed with a torsion meter for measuring the torque. Tests were conducted on the effect of the angle between the propeller axis and the wind direction. The results presented correspond to a first series of tests made without an interposed wing and in which the distance between the … more
Date: March 1937
Creator: Panetti, M.
Item Type: Refine your search to only Report
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Valve-Spring Surge

Description: Test equipment is described that includes a system of three quartz indicators whereby three different pressures could be synchronized and simultaneously recorded on a single oscillogram. This equipment was used to test the reliction of waves at ends of valve spring, the dynamical stress of the valve spring for a single lift of the valve, and measurement of the curve of the cam tested. Other tests included simultaneous recording of the stress at both ends of the spring, spring oscillation during… more
Date: March 1937
Creator: Marti, Willy
Item Type: Refine your search to only Report
open access

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
open access

Universal Logarithmic Law of Velocity Distribution as Applied to the Investigation of Boundary Layer and Drag of Streamline Bodies at Large Reynolds Number

Description: In the present paper we shall consider a figure of revolution, so that the formulas applicable to the more simple cases as, for example, a wing or flat plate will follow from our equations as corollaries. For checking the results of our theory, we made use of the data derived from the tests of Freeman on a 1/40-scale model of the airship "Akron" conducted in the large NACA wind tunnel. In the first part we shall derive the fundamental equation for a body of revolution according to the Karman th… more
Date: November 1937
Creator: Gurjienko, G.
Item Type: Refine your search to only Report
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Synthetic Resins in Aircraft Construction - Their Composition, Properties, Present State of Development and Application to Light Structures

Description: This report gives a brief review of the properties that have been attained with the synthetic materials with which we are at present familiar. Results of investigations are presented as well as possibilities for construction applications. Endurance strength and bonding tests are also presented.
Date: November 1937
Creator: Riechers, K.
Item Type: Refine your search to only Report
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Research and Design Problems Introduced by Increased Power Output

Description: In what follows the question of the number and geometrical arrangement of the cylinders so important in the design of high performance power units will be considered from various points of view. A discussion will be given of the possibilities of the various working processes and an investigation will be made of possible means for improving the continuous operation and take-off performance, particularly the methods of supercharging, increasing the r.p.m., and employing the two-stroke-cycle engin… more
Date: October 1937
Creator: Kurtz, Oskar
Item Type: Refine your search to only Report
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The Strength of Shell Bodies: Theory and Practice

Description: "The monocoque form of airplane construction has introduced a number of new problems to the stress calculator and the designer. The problems for the stress calculator fall into two groups: the determination of the stress condition (shell statics) and the determination of the failing strength (shell strength). The present report summarizes the most important theoretical and experimental results on this subject" (p. 1).
Date: September 1937
Creator: Ebner, H.
Item Type: Refine your search to only Report
open access

The Ground Effect on Lifting Propellers

Description: In what follows an estimate will be made of the magnitude of the ground effect. For the two cases where the distance a of the propeller from the ground is very small, and very large, respectively, in comparison with the propeller radius r(sub o) the relations may be simply expressed. We consider first the effect of the ground, assuming that the thrust is held constant, as may be done by a suitable change in the propeller speed.
Date: August 1937
Creator: Betz, A.
Item Type: Refine your search to only Report
open access

Pressure Distribution on a Wing Section With Slotted Flap in Free Flight Tests

Description: "The pressure distribution was measured in flight on a wing section with a slotted flap for several flap deflections, and the results obtained are presented. The test apparatus and the procedure employed in obtaining the results are also described. A Fieseler type F 5 R airplane was used for the tests" (p. 1).
Date: August 1937
Creator: Kiel, Georg
Item Type: Refine your search to only Report
open access

The Stability of Orthotropic Elliptic Cylinders in Pure Bending

Description: "The theoretical critical bending stress of elliptic cylindrical shells is determined on the assumption of infinite shell length and absence of local instability phenomena. The results of the tests on isotropic elliptic cylindrical shells stressed in bending are compared with the theoretical results. The practical applicability of the theory is discussed" (p. 1).
Date: July 1937
Creator: Heck, O. S.
Item Type: Refine your search to only Report
open access

The apparent width of the plate in compression

Description: This report discusses an investigation that treats the load capacity of a rectangular plate stressed in compression on one direction (x) beyond the buckling limit and the plate is rotatable (i.e., free from moments) supported at all four sides by bending-resistant beams.
Date: July 1937
Creator: Marguerre, Karl
Item Type: Refine your search to only Report
open access

Contributions to the Theory of Incomplete Tension Bay

Description: The present report offers an approximate theory for the stress and deformation condition after buckling of the skin in reinforced panels and shells loaded in simple shear and compression and under combined stresses. The theory presents a unified scheme for stresses of these types. It is based upon the concept of a nonuniform stress distribution in the metal panel and its marked power of resistance against compressive stresses ("incomplete" tension bay).
Date: July 1937
Creator: Schapitz, E.
Item Type: Refine your search to only Report
open access

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.
Item Type: Refine your search to only Report
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