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Investigation of turbulence in wind tunnels by a study of the flow about cylinders

Description: "With the assistance and cooperation of the National Advisory Committee for Aeronautics the Bureau of Standards has been engaged for the past year in an investigation of turbulence in wind tunnels, especially in so far as turbulence affects the results of measurements in different wind tunnels. Two methods of making such studies are described in this report together with the results of the use in the 54-inch wind tunnel of the Bureau of Standards. The first method consists in measuring the drag… more
Date: 1926
Creator: Dryden, H. L. & Heald, R. H.
Partner: UNT Libraries Government Documents Department
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Fuels for High-Compression Engines

Description: "From theoretical considerations one would expect an increase in power and thermal efficiency to result from increasing the compression ratio of an internal combustion engine. In reality it is upon the expansion ratio that the power and thermal efficiency depend, but since in conventional engines this is equal to the compression ratio, it is generally understood that a change in one ratio is accompanied by an equal change in the other. Tests over a wide range of compression ratios (extending to… more
Date: 1926
Creator: Sparrow, Stanwood W.
Partner: UNT Libraries Government Documents Department
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Aerodynamic Characteristics of Airfoils 4: Continuation of Reports Nos. 93, 124, and 182

Description: This collection of data on airfoils has been made from the published reports of a number of the leading Aerodynamic Laboratories of this country and Europe. The information which was originally expressed according to the different customs of the several laboratories is here presented in a uniform series of charts and tables suitable for the use of designing engineers and for purposes of general reference. The authority for the results here presented is given as the name of the laboratory at whi… more
Date: September 1926
Partner: UNT Libraries Government Documents Department
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Water Model Tests for Semirigid Airships

Description: The design of complicated structures often presents problems of extreme difficulty which are frequently insoluble. In many cases, however, the solution can be obtained by tests on suitable models. These model tests are becoming so important a part of the design of new engineering structures that their theory has become a necessary part of an engineer's knowledge. For balloons and airships water models are used. These are models about 1/30 the size of the airship hung upside down and filled with… more
Date: 1926
Creator: Tuckerman, L. B.
Partner: UNT Libraries Government Documents Department
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Stability Equations for Airship Hulls

Description: In the text are derived simple formulae for determining, directly from the data of wind tunnel tests of a model of an airship hull, what shall be the approximate character of oscillation, in pitch or yaw, of the full-scale airship when slightly disturbed from steady forward motion. (author).
Date: 1926
Creator: Zahm, A. F.
Partner: UNT Libraries Government Documents Department
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A Résumé of the Advances in Theoretical Aeronautics Made by Max M. Munk

Description: "In order to apply profitably the mathematical methods of hydrodynamics to aeronautical problems, it is necessary to make simplifications in the physical conditions of the latter. In a valuable paper presented by Dr. Max M. Munk, of the National Advisory Committee for Aeronautics, Washington, to the Delft Conference in April, 1924, these necessary simplifying assumptions are discussed in detail. It is the purpose of the present paper to present in as simple a manner as possible some of the inte… more
Date: 1926
Creator: Ames, Joseph S.
Partner: UNT Libraries Government Documents Department
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Wing Spar Stress Charts and Wing Truss Proportions

Description: "In order to simplify the calculation of beams continuous over three supports, a series of charts have been calculated giving the bending moments at all the critical points and the reactions at all supports for such members. Using these charts as a basis, calculations of equivalent bending moments, representing the total stresses acting in two bay-wing trusses of proportions varying over a wide range, have been determined, both with and without allowance for column effect. This leads finally to… more
Date: 1926
Creator: Warner, Edward P.
Partner: UNT Libraries Government Documents Department
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Preliminary Wing Model Tests in the Variable Density Wind Tunnel of the National Advisory Committee for Aeronautics

Description: "This report contains the results of a series of tests with three wing models. By changing the section of one of the models and painting the surface of another, the number of models tested was increased to five. The tests were made in order to obtain some general information on the air forces on wing sections at a high Reynolds number and in particular to make sure that the Reynolds number is really the important factor, and not other things like the roughness of the surface and the sharpness o… more
Date: 1926
Creator: Munk, Max M.
Partner: UNT Libraries Government Documents Department
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Standard atmosphere - tables and data

Description: Detailed tables of pressures and densities are given for altitudes up to 20,000 meters and to 65,000 feet. In addition to the tables the various data pertaining to the standard atmosphere have been compiled in convenient form for ready reference. This report is an extension of NACA-TR-147.
Date: January 1926
Creator: Diehl, Walter S.
Partner: UNT Libraries Government Documents Department
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Some Aspects of the Comparison of Model and Full-Scale Tests

Description: This paper was delivered before the Royal Aeronautical Society as the 1925 Wilbur Wright Memorial lecture. It treats the subject of scale effect from the standpoint of the engineer rather than the physicist, in that it shows what compromises are necessary to secure satisfactory engineering model test data and how these test data compare with full scale or with theoretical values. The paper consists essentially of three parts: (1) a brief exposition of the theory of dynamic similarity, (2) appli… more
Date: 1926
Creator: Taylor, D. W.
Partner: UNT Libraries Government Documents Department
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Comparison of tests on air propellers in flight with wind tunnel model tests on similar forms

Description: From Summary: "The purpose of this investigation was to determine the performance, characteristics, and coefficients of full-sized air propellers in flight and to compare these results with those derived from wind-tunnel tests on reduced scale models of similar geometrical form. The full-scale equipment comprised five propellers in combination with a VE-7 airplane and Wright E-4 engine. This part of the work was carried out at the Langley Memorial Aeronautical Laboratory, between May 1 and Augu… more
Date: 1926
Creator: Durand, W. F. & Lesley, E. P.
Partner: UNT Libraries Government Documents Department
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Preliminary flight tests of the N.A.C.A. Roots type aircraft engine supercharger

Description: "An investigation of the suitability of the N.A.C.A. Roots type aircraft engine supercharger to flight-operating conditions, as determined the effects of the use of the supercharger upon engine operation and airplane performance, is described in this report. Attention was concentrated on the operation of the engine-supercharger unit and on the improvement of climbing ability; some information concerning high speeds at altitude was obtained. The supercharger was found to be satisfactory under fl… more
Date: December 29, 1926
Creator: Gardiner, Arthur W. & Reid, Elliott G.
Partner: UNT Libraries Government Documents Department
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Air force and moment for N-20 wing with certain cut-outs

Description: From Introduction: "The airplane designer often finds it necessary, in meeting the requirements of visibility, to remove area or to otherwise locally distort the plan or section of an airplane wing. This report, prepared for the Bureau of Aeronautics January 15, 1925, contains the experimental results of tests on six 5 by 30 inch N-20 wing models, cut out or distorted in different ways, which were conducted in the 8 by 8 foot wind tunnel of the Navy Aerodynamical Laboratory in Washington in 192… more
Date: November 29, 1926
Creator: Smith, R. H.
Partner: UNT Libraries Government Documents Department
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Spray penetration with a simple fuel injection nozzle

Description: The purpose of the tests covered by this report was to obtain specific information on the rate of penetration of the spray from a simple injection nozzle, having a single orifice with a diameter of 0.015 inch when injecting into compressed gases. The results have shown that the effects of both chamber and fuel pressures on penetration are so marked that the study of sprays by means of high-speed photography or its equivalent is necessary if the effects are to be appreciated sufficiently to enab… more
Date: 1926
Creator: Miller, Harold E. & Beardsley, Edward G.
Partner: UNT Libraries Government Documents Department
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Improving the Performance of a Compression Ignition Engine by Directing Flow of Inlet Air

Description: "The object of this report is to present the results of tests performed by the National Advisory Committee for Aeronautics to determine the effect on engine performance of directing the flow of the inlet air to a 5-inch by 7-inch cylinder, solid injection, compression ignition engine, After a few preliminary tests, comparative runs were made at a speed of 1500 r.p.m. with and without directed air flow. It was found that directing the flow of the inlet air toward the fuel injection valve gave st… more
Date: July 1926
Creator: Kemper, Carlton
Partner: UNT Libraries Government Documents Department
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N.A.C.A. Flight-Path Angle and Air-Speed Recorder

Description: "A new trailing bomb-type instrument for photographically recording the flight-path angle and air speed of aircraft in unaccelerated flight is described. The instrument consists essentially of an inclinometer, air-speed meter and a film-drum case. The inclinometer carries an oil-damped pendulum which records optically the flight-path angle upon a rotating motor-driven film drum. The air-speed meter consists of a taut metal diaphragm of high natural frequency which is acted upon by the pressure … more
Date: April 1926
Creator: Coleman, Donald G.
Partner: UNT Libraries Government Documents Department
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