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Critical Compressive Stress for Flat Rectangular Plates Supported Along all Edges and Elastically Restrained Against Rotation Along the Unloaded Edges

Description: A chart is presented for the values of the coefficient in the formula for the critical compressive stress at which buckling may be expected to occur in flat rectangular plates supported along all edges and, in addition, elastically restrained against rotation along the unloaded edges. The mathematical derivations of the formulas required in the construction of the chart are given.
Date: May 1941
Creator: Lundquist, Eugene E. & Stowell, Elbridge Z.
Partner: UNT Libraries Government Documents Department

A Remote Indicating Hinge-Moment Balance, Special Report

Description: This report describes an electrical hinge-moment balance for use with wind-tunnel models of aircraft. A brief description of the principle of operation and operating experience with the balance is given in part I. Part II gives constructional details and part III gives theoretical considerations. Extensive constructional information is given to enable the reproduction of the equipment.
Date: August 1941
Creator: Stoller, Morton J. & Ribner, Herbert S.
Partner: UNT Libraries Government Documents Department

Restraint Provided a Flat Rectangular Plate by a Sturdy Stiffener Along an Edge of the Plate, Special Report

Description: A sturdy stiffener is defined as a stiffener of such proportions that it does not suffer cross-sectional distortion when moments are applied to some part of the cross section. When such a stiffener is attached to one edge of a plate, it will resist rotation of that edge of the plate by means of its torsional properties. A formula is given for the restraint coefficient provided the plate by such a stiffener. This coefficient is required for the calculation of the critical compressive stress of the plate.
Date: May 1941
Creator: Lundquist, Eugene E. & Stowell, Elbridge Z.
Partner: UNT Libraries Government Documents Department

Propeller-Design Problems of High-Speed Airplanes, Special Report

Description: "It is shown that on the basis of existing high-speed airfoil data, propeller efficiencies appreciably in excess of 40% do not appear possible at speeds above 500 miles per hour at 20,000 feet. The assumption that present propeller-blade thicknesses cannot be reduced radically, is implied. Until the reliability and applicability of the airfoil data are established, this conclusion must not be regarded as infallible. Dive tests with airplanes equipped with thrust meters and torque meters are proposed to provide an urgently needed check" (p. 1).
Date: April 1941
Creator: Dickinson, H. B.
Partner: UNT Libraries Government Documents Department

Wind-Tunnel Investigation of an NACA 66,2-216 Low-Drag Wing with Split Flaps of Various Sizes, Special Report

Description: "An investigation was conducted in the NACA 19-foot pressure wind tunnel of a rectangular wing having NACA 66, 2-216 low-drag airfoil sections and various sizes of simple split flaps. The purpose of the investigation was, primarily, to determine the influence of these flap installations on the aerodynamic characteristics of the wing. Complete lift, drag, and pitching-moment characteristics were determined for a range of test Reynolds numbers from about 2,600,000 to 4,600,000 for each of the installations and for the plain wing" (p. 1).
Date: September 1941
Creator: Muse, Thomas C. & Neely, Robert H.
Partner: UNT Libraries Government Documents Department

Wind-Tunnel Investigation of an NACA Low-Drag Tapered Wing With Straight Trailing Edge and Simple Split Flaps, Special Report

Description: Report discusses the results of an investigation to determine the effect of the split flaps on the aerodynamic characteristics of the tapered wing. The results indicated that values of maximum lift coefficient obtained from the NACA low-drag sections are comparable to values obtained on tapered wings with conventional sections. The addition of split flaps did not appreciably alter the pattern of the stall.
Date: December 1941
Creator: Muse, Thomas C. & Neely, Robert H.
Partner: UNT Libraries Government Documents Department

Wind-Tunnel Investigation of Several Factors Affecting the Performance of a High-Speed Pursuit Airplane With Air-Cooled Radial Engine

Description: Report details an investigation into various potential improvements and modifications to pursuit airplanes. NACA low-drag airfoil sections and their use for reducing drag and increasing compressibility speeds were examined. Other items covered include the propeller slipstream, high-speed cowling arrangement, and placement of wing guns.
Date: November 1941
Creator: Wenzinger, Carl J.
Partner: UNT Libraries Government Documents Department

Wind-Tunnel Tests of Several Model Tractor-Propeller and Pusher-Propeller Wing Extension-Shaft Arrangements, Special Report

Description: "Tests were made in the 20-foot propeller-research tunnel to investigate the possibility of obtaining increased net efficiencies of propeller-nacelle units by enclosing the engines in the wings and by using extension shafts. A wing of 5-foot chord was fitted with a propeller drive assembly providing for several axial locations of tractor propellers and pusher propellers. A three-blade 4-foot propeller and a three-blade 3 1/2-foot propeller of special design were tested in this wing with spinners and fairings ranging in diameter from 6 to 16 inches" (p. 1).
Date: June 1941
Creator: Harmon, Hubert N.
Partner: UNT Libraries Government Documents Department

Tests of Wing Machine-Gun and Cannon Installations in the NACA Full-Scale Wind Tunnel, Special Report

Description: "At the request of the Bureau of Aeronautics, an investigation was conducted in the full-scale wind tunnel of wing installations of .50-caliber machine guns and 20-millimeter cannons. The tests were made to determine the effect of various gun installations on the maximum lift and the high-speed drag of the airplane" (p. 1).
Date: August 1941
Creator: Czarnecki, K. R. & Guryansky, Eugene R.
Partner: UNT Libraries Government Documents Department

The Effect of Various Wing-Gun Installations on the Aerodynamic Characteristics of an Airplane Model Equipped with an NACA Low-Drag Wing, Special Report

Description: "An investigation was made in the NACA 19-foot pressure wind tunnel to determine the effect of various win-gun installation on the aerodynamic characteristics of a model with an NACA low-drag wing. Measurements were made of lift and drag over an angle-of-attack range and for several values of dynamic pressure on a four-tenths scale model of a high-speed airplane equipped with the low-drag wing and with various wing-gun installations. Two installations were tested: one in which the blast tube and part of the gun barrel protrude ahead of the wing and another in which the guns is mounted wholly within the wing" (p. 1).
Date: July 1941
Creator: Muse, Thomas C.
Partner: UNT Libraries Government Documents Department

Drag of Several Gunner's Enclosures at High Speeds

Description: "The drag of several types of gunner's turrets, windshields, blisters, and other protuberances, including projecting guns, was investigated at speeds from 75 to 440 miles per hour in the NACA 8-foot high-speed wind tunnel. The various gunner's enclosures were represented by 1/10 and 1/7 full-size models on a midwing-fuselage combination representative of bomber types. Most of the usual types of retractable turrets are very poor aerodynamically; they caused wind drag increments, dependent upon the size of the turret relative to the fuselage and upon the speed, up to twice the drag of the fuselage alone" (p. 1).
Date: July 1941
Creator: Stack, John & Moberg, Richard J.
Partner: UNT Libraries Government Documents Department

Comparison of Intercooler Characteristics

Description: "A method is presented of comparing the performance, weight, and general dimensional characteristics of inter-coolers. The performance and dimensional characteristics covered in the comparisons are cooling effectiveness, pressure drops and weight flows of the charge and cooling air, power losses, volume, frontal area, and width. A method of presenting intercooler data is described in which two types of charts are plotted; (1) A performance chart setting forth all the important characteristics of a given intercooler and (2) a replot of these characteristics for a number of intercoolers intended to assist in making a selection to satisfy a given set of installation conditions" (p. 1).
Date: May 1941
Creator: Reuter, J. George & Valerino, Michael F.
Partner: UNT Libraries Government Documents Department

Compressibility Effects in Aeronautical Engineering

Description: "Compressible-flow research, while a relatively new field in aeronautics, is very old, dating back almost to the development of the first firearm. Over the last hundred years, researches have been conducted in the ballistics field, but these results have been of practically no use in aeronautical engineering because the phenomena that have been studied have been the more or less steady supersonic condition of flow. Some work that has been done in connection with steam turbines, particularly nozzle studies, has been of value, In general, however, understanding of compressible-flow phenomena has been very incomplete and permitted no real basis for the solution of aeronautical engineering problems in which.the flow is likely to be unsteady because regions of both subsonic and supersonic speeds may occur" (p. 1).
Date: August 1941
Creator: Stack, John
Partner: UNT Libraries Government Documents Department

Critical Compressive Stress for Outstanding Flanges

Description: "A chart is presented for the values of the coefficient in the formula for the critical compressive stress at which buckling may be expected to occur in outstanding flanges. These flanges are flat rectangular plates supported along the Loaded edges, supported and elastically restrained along one unloaded edge, and free along the other unloaded edge. The mathematical derivations of the formulas required for the construction of the chart are given" (p. 1).
Date: April 1941
Creator: Lundquist, Eugene E. & Stowell, Elbridge Z.
Partner: UNT Libraries Government Documents Department

Characteristics of NACA 4400R Series Rectangular and Tapered Airfoils, Including the Effect of Split Flaps

Description: "At the request of the Bureau of Aeronautics, Navy Department, tests were made in the variable-density wind tunnel of a tapered wing of 3-10-18 plan form and based on the NACA 4400R series sections. The wing was also tested with 0.2 chord spit flaps, deflected 60 deg span ratios of 0.3, 0.5, 0.7 and 1.0 respectively. In order to get data from which to calculate the characteristics of the flapped wing, the investigation was extended to include tests of the four rectangular airfoils of the NACA 4400R series (4409R, 4412R, 4415R, and 4418R) with full-span 0.2 chord, trailing edge split flaps deflected 60 deg" (p. 1).
Date: January 1941
Creator: Greenberg, Harry
Partner: UNT Libraries Government Documents Department

Model Tests of a Wing-Duct System for Auxiliary Air Supply

Description: Report discusses the design of a cooling system developed for a Pratt & Whitney H-2800 engine equipped with a two-stage supercharger. The wing-duct system was newly developed and was determined to be a valuable method for cooling engine auxiliaries by combining simplicity with low drag and excellent cooling capabilities.
Date: January 1941
Creator: Bierman, David & Corson, Blake W., Jr.
Partner: UNT Libraries Government Documents Department

Performance Characteristics of an Aircraft Engine with Exhaust Turbine Supercharger, Special Report

Description: "The Pratt and Whitney Aircraft company and the Naval Aircraft Factory of the United States Navy cooperated in a laboratory and flight program of tests on an exhaust turbine supercharger. Two series of dynamometer tests of the engine super-charger combination were completed under simulated altitude conditions. One series of hot gas-chamber tests was conducted by the manufacturer of the supercharger" (p. 1).
Date: May 1941
Creator: Lester, E. M. & Paulson, W. A.
Partner: UNT Libraries Government Documents Department