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An Experimental Investigation of NACA Submerged-Duct Entrances

Description: The results of a preliminary investigation of submerged duct entrances are presented. It is shown that an entrance of this type possess desirable critical speed and pressure recovery characteristics when used on a fuselage or nacelle in a region of low incremental velocity and thin boundary layer. The data obtained indicate that submerged entrances are most suitable for use with internal-flow systems which diffuse the air only a small amount: for example, those used with jet motors which have axial-flow compressors. Where complete diffusion of the air is required, fuselage-nose or wing leading edge inlets may prove to be superior. The results of the investigation have been prepared in such a form as to permit their use by a designer and the application of these data to a specific design is discussed.
Date: October 1945
Creator: Frick, Charles W.; Davis, Wallace F.; Randall, Lauros M. & Mossman, Emmet A.
Partner: UNT Libraries Government Documents Department

Investigation of flow in an axially symmetrical heated jet of air

Description: The work done under this contract falls essentially into two parts: the first part was the design and construction of the equipment and the running of preliminary tests on the 3-inch jet, carried out by Mr. Carl Thiele in 1940; the second part consisting in the measurement in the 1-inch jet flow in an axially symmetrical heated jet of air. (author).
Date: December 1, 1943
Creator: Corrsin, Stanley
Partner: UNT Libraries Government Documents Department

Wind-tunnel investigation of control-surface characteristics 17: beveled-trailing-edge flaps of 0.20, 0.30, and 0.40 airfoil chord on an NACA 0009 airfoil

Description: Report presenting force tests in two-dimensional flow in the 4- by 6-foot vertical tunnel to determine the aerodynamic characteristics of an NACA 0009 airfoil with flaps having chord at 3 locations of the airfoil chord and three degrees of the beveled trailing edges. The results indicated that, with a smooth leading edge, the increased trailing-edge angle on the flaps with sealed gaps decreased the slope of the control-fixed lift curve and the lift effectiveness.
Date: April 1944
Creator: Lockwood, Vernard E.
Partner: UNT Libraries Government Documents Department

Wind-tunnel investigation of control-surface characteristics 13: various flap overhangs used with a 30-percent-chord flap in an NACA 66-009 airfoil

Description: Report presenting force tests in two-dimensional flow made on an NACA 66-009 airfoil with a flap having a chord 30 percent of the airfoil chord and a tab having a chord 20 percent of the flap chord. A plain flap and flaps having overhangs of 35 and 50 percent of the flap chord were tested with two gap variations: sealed and unsealed. Results regarding lift, flap hinge moments, pitching moments, drag, and tab characteristics are provided.
Date: July 1943
Creator: Gillis, Clarence L.
Partner: UNT Libraries Government Documents Department

Flight Investigation at High Speeds of Profile Drag of Wing of a P-47D Airplane Having Production Surfaces Covered with Camouflage Paint

Description: Wing section outboard of flap was tested by wake surveys in Mach range of 0.25 - 0.78 and lift coefficient range 0.06 - 0.69. Results indicated that minimum profile-drag coefficient of 0.0097 was attained for lift coefficients from 0.16 to 0.25 at Mach less than 0.67. Below Mach number at which compressibility shock occurred, variations in Mach of 0.2 had negligible effect on profile drag coefficient. Shock was not evident until critical Mach was exceeded by 0.025.
Date: March 1946
Creator: Zalovcik, John A. & Daum, Fred L.
Partner: UNT Libraries Government Documents Department

Wind-tunnel investigation of ailerons on a low-drag airfoil 1: The effect of aileron profile

Description: Report presenting an investigation in the 7- by 10-foot wind tunnel of the effects of various modifications to the profile of a 0.20-chord plain sealed aileron and a 0.15-chord plain sealed aileron on an NACA 66,2-216 airfoil. Thickening of the aileron was found to reduce the aileron effectiveness, reduce the slope of the wing section lift curve, and reduce the hinge-moment coefficients. Results regarding the section data, aileron effectiveness, aileron hinge moments, lift, pitching moment, drag, and Reynolds number are provided.
Date: January 1944
Creator: Crane, Robert M. & Holtzclaw, Ralph W.
Partner: UNT Libraries Government Documents Department

Wind-tunnel investigation of ailerons on a low-drag airfoil 2: the effect of thickened and beveled trailing edges

Description: Report presenting an investigation in the 7- by 10-foot wind tunnel of the effects of modifications to the trailing edge of a 0.20-chord plain sealed aileron on an NACA 66,2-216 airfoil. The modifications considered consisted of various amounts of symmetrical thickening and beveling of the aileron trailing edge. Results regarding aileron effectiveness, aileron hinge moments, aileron control forces, lift, pitching moment, drag, and Reynolds number are provided.
Date: January 1944
Creator: Crane, Robert M. & Holtzclaw, Ralph W.
Partner: UNT Libraries Government Documents Department

Oxygen boosting of an aircraft-engine cylinder in conjunction with internal coolants

Description: Report presenting an investigation to determine the possibility of attaining or approaching critical-altitude power at altitudes considerably higher than the critical as limited by the supercharger by the use of oxygen in conjunction with internal coolants.
Date: April 1944
Creator: Spencer, Robert C.; Jones, Anthony W. & Pfender, John F.
Partner: UNT Libraries Government Documents Department

Performance of compressor-turbine jet-propulsion systems

Description: Report presenting an analysis of the performance of compressor-turbine jet-propulsion systems carried out by calculating the thrust power from a compressor-turbine jet engine with a systematic variation of pressure ratio, fuel-air ratio, compressor and turbine efficiencies, flight speed, altitude, and maximum gas temperature.
Date: June 1945
Creator: Palmer, Carl B.
Partner: UNT Libraries Government Documents Department

The NACA impact basin and water landing tests of a float model at various velocities and weights

Description: Report presenting data obtained when a float with both horizontal and vertical velocity contact on a water surface. The report is confined to a presentation of the relationship between resultant velocity and impact normal acceleration for various float weights when all other parameters are constant.
Date: August 1944
Creator: Batterson, Sidney A.
Partner: UNT Libraries Government Documents Department

NACA Radio Ground-Speed System for Aircraft

Description: Report presenting a method utilizing the Doppler effect on radio signals for determining the speed and distance traveled of an airplane. The method is called the NACA radio ground-speed system and uses the standard radio transmitter already found in most aircraft. Flight tests were made in which the method was used and the results were consisted with calibrated airspeed indications and stop-watch measurements.
Date: February 1943
Creator: Hastings, Charles E.
Partner: UNT Libraries Government Documents Department

Preliminary Report on Laminar-Flow Airfoils and New Methods Adopted for Airfoil and Boundary-Layer Investigations

Description: Recent developments in airfoil-testing methods and fundamental air-flow investigations, as applied to airfoils, are discussed. Preliminary test results, obtained under conditions relatively free from stream turbulence and other disturbances, are presented. Suitable airfoils and airfoil-design principles were developed to take advantage of the unusually extensive laminar boundary layers that may be maintained under the improved testing conditions. The results are of interest mainly in range of below 6,000,000.
Date: June 1, 1939
Creator: Jacobs, Eastman N.
Partner: UNT Libraries Government Documents Department

Considerations of wake-excited vibratory stress in a pusher propeller

Description: Report presenting an equation based on simple blade-element theory and the assumption of a fixed wake pattern is derived and fitted to available data to show the first-order relation between the parameters of propeller operation and intensity of wake-excited periodic force acting on the blades of a pusher propeller. The derived equation indicates that the effect of power coefficient on the intensity of the wake-excited periodic force is small. Limited data also indicates that the wake-excited vibratory stress in a propeller increases with the drag of the body producing the wake.
Date: February 1944
Creator: Corson, Blake W., Jr.
Partner: UNT Libraries Government Documents Department

Preliminary Investigation in the NACA Low-Turbulence Tunnel of Low-Drag Airfoil Sections Suitable for Admitting Air at the Leading Edge

Description: From Summary: "An investigation was carried out in the NACA low-turbulence tunnel to develop low-drag airfoil sections suitable for admitting air at the leading edge. A thickness distribution having the desired type of pressure distribution was found from tests of a flexible model. Other airfoil shapes were derived from this original shape by varying the thickness, the camper, the leading-edge radius, and the size of the leading-edge opening. Data are presented giving the characteristics of the airfoil shapes in the range of lift coefficients for high-speed and cruising flight."
Date: July 1942
Creator: von Doenhoff, Albert E. & Horton, Elmer A.
Partner: UNT Libraries Government Documents Department

Flight tests of exhaust-gas jet propulsion

Description: From Summary: "Flight tests were conducted on the XP-41 airplane, equipped with a Pratt & Whitney R1830-19, 14-cylinder, air-cooled engine, to determine the increase in flight speed obtainable by the use of individual exhaust stacks directly rearwardly to obtain exhaust-gas thrust. Speed increases up to 13 miles per hour at 20,000 feet altitude were obtained using stacks having an exit area of 3.42 square inches for each cylinder. A slight increase in engine power and decrease in cylinder temperature at a given manifold pressure were obtained with the individual stacks as compared with a collector-ring installation."
Date: November 1940
Creator: Pinkel, Benjamin & Turner, L. Richard
Partner: UNT Libraries Government Documents Department

Wind-Tunnel Investigation of a Low-Drag Airfoil Section with a Double Slotted Flap

Description: From Summary: "Tests were made of an 0.309-chord double-slotted flap on an NACA 65, 3-118, a equals 1.0 airfoil section to determine drag, lift, and pitching-moment characteristics for a range of flap deflections. Results indicate that combination of a low-drag airfoil and a double-slotted flap, of which the two parts moved as a single unit, gave higher maximum lift coefficients than have been obtained with plain, split, or slotted flaps on low-drag airfoils. Pitching moments were comparable to those obtained with other high-lift devices on conventional airfoils for similar lift coefficients."
Date: September 1943
Creator: Bogdonoff, Seymour M.
Partner: UNT Libraries Government Documents Department

The effect of external shape upon the drag of a scoop

Description: Report presenting testing of six scoops built using the principles of NACA cowling design to show the advantage of using those principles. Three scoops had a good nose contour with different afterbody lengths and three were of inferior nose shape. Results regarding drag, cooling pressure, and surface pressure survey are provided.
Date: July 1941
Creator: Naiman, Irven & Hill, Paul R.
Partner: UNT Libraries Government Documents Department

Effect of Compressibility on Pressure Distribution over an Airfoil with a Slotted Frise Aileron

Description: Pressure distribution measurements were made over an airfoil with slotted Frise aileron up to 0.76 Mach at various angles of attack and aileron defections. Section characteristics were determined from these pressure data. Results indicated loss of aileron rolling power for deflections ranging from -12 Degrees to -19 Degrees. High stick forces for non-differential deflections incurred at high speed, which were due to overbalancing tendency of up-moving aileron, may precipitate serious control difficulties. Detailed results are presented graphically.
Date: July 1, 1944
Creator: Luoma, Avro A
Partner: UNT Libraries Government Documents Department

A correlation of the effects of compression ratio and inlet-air temperature on the knock limits of aviation fuels in a CFR engine 1

Description: Report presenting a method of correlating the effects of compression ratio and inlet-air temperature on the knock limits of aviation fuels. Knock-limited performance tests of several fuels were run to check the method.
Date: May 1945
Creator: Evvard, John C. & Branstetter, J. Robert
Partner: UNT Libraries Government Documents Department