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  Partner: UNT Libraries Government Documents Department
 Decade: 1940-1949
 Serial/Series Title: NACA Special Report
 Collection: Technical Report Archive and Image Library
Performance Characteristics of an Aircraft Engine with Exhaust Turbine Supercharger, Special Report

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

Date: May 1, 1941
Creator: Lester, E. M. & Paulson, V. A.
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. Flight demonstrations of the supercharger installed in a twin-engine flying boat were terminated by failure of the turbine wheels. The analysis of the results indicated that a two-stage supercharger with the first-stage exhaust turbine driven will deliver rated power for a given indicated power to a higher altitude, will operate more efficiently, and will require simpler controls than a similar engine with the first stage of the supercharger driven from the crankshaft through multispeed gears.
Contributing Partner: UNT Libraries Government Documents Department
Propeller-Design Problems of High-Speed Airplanes, Special Report

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

Date: April 1, 1941
Creator: Dickinson, H. B.
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. The design of high-speed propellers is dictated wholly by compressibility considerations. The blade width, thickness, and pitch distribution; also the airfoil sections, the lift coefficient, the propeller diameter, and rpm must all be adjusted if reasonable efficiencies are to be maintained at airplane speeds that are now being approached. Research is urgently needed on: 1) airfoils at subsonic, sonic, and supersonic speeds; 2) propellers at high forward speeds in wind tunnels; 3)propellers in free flight at high speeds; and 4) jet propulsion and related devices. The breakdown of propeller efficiency indicated by airfoil data, should serve as an incentive for accelerated research on jet propulsion. This device may extend the attainable speed of current airplanes to the ...
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Wind-Tunnel Development of Ailerons for the Curtiss XP-60 Airplanem Special Report

Wind-Tunnel Development of Ailerons for the Curtiss XP-60 Airplanem Special Report

Date: September 1, 1942
Creator: Rogallo, F. M. & Lowry, John G.
Description: An investigation was made in the LWAL 7- by 10-foot tunnel of internally balanced, sealed ailerons for the Curtiss XP-60 airplane. Ailerons with tabs and. with various amounts of balance were tested. Stick forces were estimated for several aileron arrangements including an arrangement recommended for the airplane. Flight tests of the recommended arrangement are discussed briefly in an appendix, The results of the wind-tunnel and flight tests indicate that the ailerons of large or fast airplanes may be satisfactorily balanced by the method developed.
Contributing Partner: UNT Libraries Government Documents Department
Wind-Tunnel Investigation of Rectangular Air-Duct Entrances in the Leading Edge of an NACA 23018 Wing, Special Report

Wind-Tunnel Investigation of Rectangular Air-Duct Entrances in the Leading Edge of an NACA 23018 Wing, Special Report

Date: September 1, 1940
Creator: Biermann, David & McLellan, Charles H.
Description: A preliminary investigation of a number of duct entrances of rectangular shape installed in the leading edge of a wing was conducted in the NACA 20-foot tunnel to determine the external drag, the available pressure, the critical Mach numbers, and the effect on the maximum lift. The results showed that the most satisfactory entrances, which had practically no effect on the wing characteristics, had their lips approximately in the vertical plane of the leading edge of the wing. This requirement necessitated extending the lips outside the wing contour for all except the small entrances. Full dynamic pressure was found to be available over a fairly wide range of angle of attack. The critical Mach number for a small entrance was calculated to be as high as that for the plain wing but was slightly lower for the larger entrances tested.
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Wind-tunnel investigation of several factors affecting the performance of a high-speed pursuit airplane with air-cooled radial engine

Wind-tunnel investigation of several factors affecting the performance of a high-speed pursuit airplane with air-cooled radial engine

Date: November 1, 1941
Creator: Wenzinger, C. J.
Description: None
Contributing Partner: UNT Libraries Government Documents Department
Preliminary Investigation of the Effect of Compressibility on the Maximum Lift Coefficient, Special Report

Preliminary Investigation of the Effect of Compressibility on the Maximum Lift Coefficient, Special Report

Date: February 1, 1943
Creator: Stack, John; Fedziuk, Henry A. & Cleary, Harold E.
Description: Preliminary data are presented on the variation of the maximum lift coefficient with Mach number. The data were obtained from tests in the 8-foot high-speed tunnel of three NACA 16-series airfoils of 1-foot chord. Measurements consisted primarily of pressure-distribution measurements in order to illustrate the nature of the phenomena. It was found that the maximum lift coefficient of airfoils is markedly affected by compressibility even at Mach numbers as low as 0.2. At high Mach numbers pronounced decrease of the maximum lift coefficient was found. The magnitude of the effects of compressibility on the maximum lift coefficient and the low speeds at which these effects first appear indicate clearly that consideration of the take-off thrust for propellers will give results seriously in error if these considerations are based on the usual low-speed maximum-lift-coefficient data generally used.
Contributing Partner: UNT Libraries Government Documents Department
Preliminary Wind-Tunnel Tests of the Effect of Nacelles on the Characteristics of a Twin-Engine Bomber Model with Low-Drag Wing, Special Report

Preliminary Wind-Tunnel Tests of the Effect of Nacelles on the Characteristics of a Twin-Engine Bomber Model with Low-Drag Wing, Special Report

Date: July 1, 1942
Creator: Wenzinger, Carl J. & Sivells, James C.
Description: Tests were made in the NACA 19-foot pressure tunnel of a simplified twin-engine bomber model with an NACA low-drag wing primarily to obtain an indication of the effects of engine nacelles on the characteristics of the model both with and without simple split trailing-edge flaps. Nacelles with conventional-type cowlings representative of those used on an existing high-performance airplane and with NACA high-speed type E cowlings were tested. The tests were made without propeller slipstream. The aerodynamic effects of adding the nacelles to the low-drag wing were similar to the effects commonly obtained by adding similar nacelles to conventional wings. The maximum lift coefficient without flaps was slightly increased, but the increment in maximum lift due to deflecting the flaps was somewhat decreased. The stalling characteristics were improved by the presence of the nacelles. Addition of the nacelles had a destabilizing effect on the pitching moments, as is usual for nacelles that project forward of the wing. The drag increments due to the nacelles were of the usual order of magnitude, with the increment due to the nacelles with NACA type E cowlings approximately one-third less than that of the nacelles with conventional cowlings with built-in air scoops.
Contributing Partner: UNT Libraries Government Documents Department
Restraint Provided a Flat Rectangular Plate by a Sturdy Stiffener Along an Edge of the Plate, Special Report

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

Date: May 1, 1941
Creator: Lundquist, Eugene E. & Stowell, Elbridge Z.
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.
Contributing Partner: UNT Libraries Government Documents Department
A Remote Indicating Hinge-Moment Balance, Special Report

A Remote Indicating Hinge-Moment Balance, Special Report

Date: August 1, 1941
Creator: Stoller, Morton J. & Ribner, Herbert S.
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.
Contributing Partner: UNT Libraries Government Documents Department
Wind-Tunnel Investigation of the Lift Characteristics of an NACA 27-212 Airfoil Equipped with Two Types of Flap, Special Report

Wind-Tunnel Investigation of the Lift Characteristics of an NACA 27-212 Airfoil Equipped with Two Types of Flap, Special Report

Date: September 1, 1940
Creator: Swanson, Robert S. & Schuldenfrei, Marvin J.
Description: An investigation has been made in the NACA 7- by 10-foot wind tunnel of a large chord NACA 27-212 airfoil with a 20% chord split flap and with two arrangements of a 25.66% chord slotted flap to determine the section lift characteristics as affected by flap deflection for the split flap and as affected by flap deflection, flap position, and slot shape for the slotted flap. For the two arrangements of the slotted flap, the flap positions for maximum section lift are given. Comparable data on the NACA 23012 airfoil equipped with similar flaps are also given. On the basis of maximum section lift coefficient, the slotted flap with an easy slot entry was slightly better than either the split flap or the slotted flap with a sharp slot entry. With both types of flap the decrease in the angle of attack, for maximum section lift coefficient, with flap deflection is large for the NACA 27-212 airfoil as compared with the NACA 23012 airfoil. Also with both flaps, the maximum section lift coefficient obtained with flaps is much lower for the NACA 27-212 airfoil than for the NACA 23012 airfoil.
Contributing Partner: UNT Libraries Government Documents Department
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