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Design of NACA Cowlings for Radial Air-Cooled Engines

Description: "The information on the propeller-cowling-nacelle combinations, presented in Technical Reports nos. 592, 593, and 596 and in Technical Note 620, is applied to the practical design of NACA cowlings. The main emphasis is placed on the method of obtaining the dimensions of the cowling; consequently, the physical functioning of each part of the cowling is treated very briefly. A practical method of designing cowlings and some examples are presented" (p. 383).
Date: March 5, 1938
Creator: Stickle, George W.
Partner: UNT Libraries Government Documents Department
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Cooling on the front of an air-cooled engine cylinder in a conventional engine cowling

Description: Measurements were made of the cooling on the fronts of model cylinders in a conventional cowling for cooling in both the ground and the cruising conditions. The mechanisms of front and rear cooling are essentially different. Cooling on the rear baffled part of the cylinders continually increases with increasing fin width. For the front of the cylinder, an optimum fin width was found to exist beyond which an increase in width reduced the heat transfer. The heat transfer coefficient on the front … more
Date: April 5, 1939
Creator: Brevoort, M. J. & Joyner, U. T.
Partner: UNT Libraries Government Documents Department
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Interference of Tail Surfaces and Wing and Fuselage from Tests of 17 Combinations in the N.A.C.A. Variable-Density Tunnel

Description: "An investigation of the interference associated with tail surfaces added to wing-fuselage combinations was included in the interference program in progress in the NACA variable-density tunnel. The results indicate that, in aerodynamically clean combinations, the increment of the high-speed drag can be estimated from section characteristics within useful limits of accuracy. The interference appears mainly as effects on the downwash angle and as losses in the tail effectiveness and varies with t… more
Date: November 5, 1938
Creator: Sherman, Albert
Partner: UNT Libraries Government Documents Department
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Auto-Ignition and Combustion of Diesel Fuel in a Constant-Volume Bomb

Description: Report presents the results of a study of variations in ignition lag and combustion associated with changes in air temperature and density for a diesel fuel in a constant-volume bomb. The test results have been discussed in terms of engine performance wherever comparisons could be drawn. The most important conclusions drawn from this investigation are: the ignition lag was essentially independent of the injected fuel quantity. Extrapolation of the curves for the fuel used shows that the lag cou… more
Date: October 5, 1937
Creator: Selden, Robert F.
Partner: UNT Libraries Government Documents Department
open access

Reduction of hinge moments of airplane control surfaces by tabs

Description: This report presents the results of an investigation conducted in the NACA 7 by 10-foot wind tunnel of control surfaces equipped with tabs for reducing the control forces or trimming the aircraft. Two sizes of ordinary ailerons with several sizes of attached and inset tabs were tested on a Clark y wing. Tabs were also tested in combination with auxiliary balances of the horn and paddle types, and with a frise balance aileron.
Date: February 5, 1935
Creator: Harris, Thomas A.
Partner: UNT Libraries Government Documents Department
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Wind-Tunnel Research Comparing Lateral Control Devices, Particularly at High Angles of Attack 3: Ordinary Ailerons Rigged Up 10 Degrees When Neutral

Description: This report presents the results of wind-tunnel tests made on three model wings having different sizes of ordinary ailerons rigged up 10 degrees when neutral, the same models having previously been tested with the ailerons rigged even with the wings in the usual manner. One of the wings had ailerons of medium size, 25 per cent of the wing chord by 40 per cent of the semispan, one had long, narrow ailerons, and one had short, wide ones. These tests are part of a general investigation on lateral … more
Date: February 5, 1932
Creator: Weick, Fred E. & Wenzinger, Carl J.
Partner: UNT Libraries Government Documents Department
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Characteristics of Clark Y airfoils of small aspect ratios

Description: This report presents the results of a series of wind tunnel tests showing the force, moment, and autorotational characteristics of Clark Y airfoils having aspect ratios varying from 0.5 to 3. An airfoil of rectangular plan form was tested with rectangular tips, flared tips, and semicircular tips. Tests were also made on one airfoil of circular plan form and two airfoils of elliptical plan form. The tests revealed a marked delay of the stall and a decided increase in values of maximum lift coeff… more
Date: May 5, 1932
Creator: Zimmerman, C. H.
Partner: UNT Libraries Government Documents Department
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The interference between struts in various combinations

Description: This report presents the results of wind tunnel tests made to determine the interference drag arising from various arrangements of streamline struts and round struts, or cylinders. Determinations were made of the interference drag of struts spaced side by side, struts in tandem, tandem struts encased in a single fairing, a strut intersecting a plane, and struts intersecting to form a v. Three sizes of struts were used for most of the tests. These tests show that the interference drag arising fr… more
Date: June 5, 1933
Creator: Biermann, David & Herrnstein, William H., Jr.
Partner: UNT Libraries Government Documents Department
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Stability of Thin-Walled Tubes Under Torsion

Description: "In this report a theoretical solution is developed for the torsion on a round thin-walled tube for which the walls become unstable. The results of this theory are given by a few simple formulas and curves which cover all cases. The differential equations of equilibrium are derived in a simpler form than previously found, it being shown that many items can be neglected" (p. 3).
Date: May 5, 1933
Creator: Donnell, L. H.
Partner: UNT Libraries Government Documents Department
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Full-scale tests of metal propellers at high tip speeds

Description: This report describes tests of 10 full-scale metal propellers of several thickness ratios at various tip speeds up to 1,350 feet per second. The results indicate no loss of efficiency up to tip speeds of approximately 1,000 feet per second. Above this tip speed the loss is at a rate of about 10 per cent per 100 feet per second increase relative to the efficiency at the lower speeds for propellers of pitch diameter ratios 0.3 to 0.4. Propellers having sections of small thickness ratio can be run… more
Date: November 5, 1930
Creator: Wood, Donald H.
Partner: UNT Libraries Government Documents Department
open access

Manual of Fire-Loss Prevention

Description: Principles of fire-resistance classifications of building types and materials, general methods for controlling the spread of fire, and general fire-prevention measures.
Date: November 5, 1934
Partner: UNT Libraries Government Documents Department
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