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Effect of turbulence in wind-tunnel measurements

Description: This paper gives some quantitative measurements of wind tunnel turbulence and its effect on the air resistance of spheres and airship models, measurements made possible by the hot wire anemometer and associated apparatus in its original form was described in Technical Report no. 320 and some modifications are presented in an appendix to the present paper. One important result of the investigation is a curve by means of which measurements of the air resistance of spheres can be interpreted to gi… more
Date: August 20, 1929
Creator: Dryden, H. L. & Kuethe, A. M.
Partner: UNT Libraries Government Documents Department
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The Effect of Reduction Gearing on Propeller-Body Interference as Shown by Full-Scale Wind-Tunnel Tests

Description: This report presents the results of full-scale tests made on a 10-foot 5-inch propeller on a geared J-5 engine and also on a similar 8-foot 11-inch propeller on a direct-drive J-5 engine. Each propeller was tested at two different pitch settings, and with a large and a small fuselage. The investigation was made in such a manner that the propeller-body interference factors were isolated, and it was found that, considering this interference only, the geared propellers had an appreciable advantage… more
Date: March 20, 1929
Creator: Weick, Fred E.
Partner: UNT Libraries Government Documents Department
open access

Full Scale Tests on a Thin Metal Propeller at Various Tip Speeds

Description: "This report describes an investigation made in order to determine the effect of tip speed on the characteristics of a thin-bladed metal propeller. The propeller was mounted on a VE-7 airplane with a 180-HP E-2 engine, and tested in the 20-foot propeller research tunnel of the National Advisory Committee for Aeronautics. It was found that the effect of tip speed on the propulsive efficiency was negligible within the range of the tests, which was from 600 to 1,000 feet per second (about 0.5 to 0… more
Date: June 20, 1928
Creator: Weick, Fred E.
Partner: UNT Libraries Government Documents Department
open access

Air Force Tests of Sperry Messenger Model With Six Sets of Wings

Description: From Summary: "The purpose of this test was to compare six well-known airfoils, the R.A.F 15, U.S.A. 5, U.S.A. 27, U.S.A. 35-B, Clark Y, and Gottingen 387, fitted to the Sperry Messenger model, at full scale Reynolds number as obtained in the variable density wind tunnel of the National Advisory Committee for Aeronautics; and to determine the scale effect on the model equipped with all the details of the actual airplane. The results show a large decrease in minimum drag coefficient upon increas… more
Date: January 20, 1927
Creator: Shoemaker, James M.
Partner: UNT Libraries Government Documents Department
open access

Drag of Wings With End Plates

Description: "In this report a formula for calculating the induced drag of multiplanes with end plates is derived. The frictional drag of the end plates are used, is sufficiently large to increase the efficiency of the wing. Curves showing the reduction of drag for monoplanes and biplanes are constructed; the influence of gap-chord ratio, aspect ratio, and height of end plate are determined for typical cases. The method of obtaining the reduction of drag for a multiplane is described" (p. 253).
Date: January 20, 1927
Creator: Hemke, Paul E.
Partner: UNT Libraries Government Documents Department
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