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A Flight Investigation of the Effect of Surface Roughness on Wing Profile Drag With Transition Fixed

Description: Report presenting a flight investigation made on a wing section of a P-47D airplane to determine the effect of roughness on wing profile drag with transition fixed far forward. Surveys of the wake were made for two surface conditions with transition fixed by a thread at 5 percent chord back of the leading edge on the upper and lower surfaces. Below the Mach number at which shock occurred, variations in Mach number of as much as 0.16 appeared to have no appreciable effect on the section profile-drag coefficients of either the smooth or roughened surfaces with transition fixed.
Date: September 1944
Creator: Zalovcik, John A. & Wood, Clotaire
Partner: UNT Libraries Government Documents Department

Static-Pressure Error of an Airspeed Installation on an Airplane in High-Speed Dives and Pullouts

Description: "Tests were made in high-speed dives and pull-outs to determine, by combined radar-optical tracking equipment, the static-pressure error of an airspeed-head installation on a P-51B airplane." The equipment used and testing procedure are described. The variation of static-pressure error is provided for several ranges of airplane lift coefficient.
Date: February 1946
Creator: Zalovcik, John A. & Wood, Clotaire
Partner: UNT Libraries Government Documents Department

Flight investigation of boundary-layer control by suction slots on an NACA 35-215 low-drag airfoil at high Reynolds numbers

Description: Report presenting an investigation of the effectiveness of suction slots a a means of extending the laminar boundary layer in flight at high Reynolds numbers using an NACA 35-215 airfoil. Tests were made over a range of indicated airspeeds, lift coefficients, and Reynolds numbers. Results regarding boundary-layer control, air-intake distributions, character of the boundary layer, total-intake rate, and profile-drag coefficient are provided.
Date: February 1944
Creator: Zalovcik, John A.; Wetmore, J. W. & von Doenhoff, Albert E.
Partner: UNT Libraries Government Documents Department

Data for Design of Entrance Vanes from Two-Dimensional Tests of Airfoils in Cascade

Description: "As a part of a program of the NACA directed toward increasing the efficiency of compressors and turbines, data were obtained for application to the design of entrance vanes for axial-flow compressors or turbines. A series of blower-blade sections with relatively high critical speeds have been developed for turning air efficiently from 0 deg to 80 deg starting with an axial direction. Tests were made of five NACA 65-series blower blades (modified NACA 65(216)-010 airfoils) and of four experimentally designed blower blades in a stationary cascade at low Mach numbers" (p. 1).
Date: October 1945
Creator: Zimmey, Charles M. & Lappi, Viola M.
Partner: UNT Libraries Government Documents Department

Correlation of exhaust-valve temperatures with engine operating conditions and valve design

Description: Report presenting a theory regarding engine-cooling variables from a previous report, which was used as a basis for the development of a semi-empirical equation to correlate exhaust-valve temperature with engine conditions. Results regarding the determination of constants, influences of operating variables on mean effective gas temperatures, thermal-resistance factor, and accuracy of correlating equation are provided.
Date: October 1945
Creator: Zipkin, M. A. & Sanders, J. C.
Partner: UNT Libraries Government Documents Department

Tests of a 0.1475c Aileron With a Tab on Low-Drag Section for Curtiss XP-60 Airplane in the Low-Turbulence Tunnel

Description: "Preliminary two-dimensional tests of the hinge-moment characteristics of a 0.1725c internally balanced aileron on the subject XP-60 wing section indicated that more internal balance would be required if light stick forces were to be obtained at high speeds. The present series of tests were therefore undertaken in order to investigate methods of reducing the slope of the hinge-moment curve while still maintaining the required aileron effectiveness" (p. 1).
Date: November 1941
Creator: von Doenhoff, A. E. & Underwood, W. J.
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

Drag measurements at high Reynolds numbers of a 100-inch-chord NACA 23016 practical construction wing section submitted by Chance Vought Aircraft Company

Description: Report presenting drag measurements in the two-dimensional low-turbulence tunnel of an available 100-inch-chord model of the NACA 23016 wing section. Results regarding the curves of section drag coefficient plotted against Reynolds number for various surface conditions and lift coefficients, variation of drag coefficient with lift coefficient, and effects of skin friction are provided.
Date: June 1944
Creator: von Doenhoff, Albert E. & Nuber, Robert J.
Partner: UNT Libraries Government Documents Department

Aerodynamic Characteristics of the NACA 747A315 and 747A415 Airfoils From Tests in the NACA Two-Dimensional Low-Turbulence Pressure Tunnel

Description: Report presenting two low-drag airfoils, the NACA 747A315 and the NACA 747A415, which are designed to have reduced pitching moments about the quarter-chord point and moderately high values of the design lift coefficient and are tested in the tow-dimensional low-turbulence pressure tunnel.
Date: September 1944
Creator: von Doenhoff, Albert E. & Stivers, Louis S., Jr.
Partner: UNT Libraries Government Documents Department

Determination of General Relations for the Behavior of Turbulent Boundary Layers

Description: Report presenting an analysis of data for turbulent boundary layers along wings and bodies of various shapes in order to determine the fundamental variables that control the development of turbulent boundary layers. Results indicate that the type of velocity distribution in the boundary layer could be expressed in terms of a single parameter.
Date: July 1943
Creator: von Doenhoff, Albert E. & Tetervin, Neal
Partner: UNT Libraries Government Documents Department

Investigation of the Variation of Lift Coefficient With Reynolds Number at a Moderate Angle of Attack on a Low-Drag Airfoil

Description: Bulletin presenting an investigation of the boundary layer about the NACA 66,2-216, a = 0.6 airfoil section in the two-dimensional low-turbulence tunnel. The primary purpose was to find an explanation for the decreased slope of the lift curve observed for some of the low-drag sections outside the low-drag range at low Reynolds numbers.
Date: November 1942
Creator: von Doenhoff, Albert E. & Tetervin, Neal
Partner: UNT Libraries Government Documents Department

Protection of Nonmetallic Aircraft From Lighting 1: General Analysis

Description: Report presenting a preliminary way to give a logical and consistent analysis of the problem of providing adequate protection to the personnel, contents, and structure of nonmetallic aircraft against the effects of electric shock, mechanical damage, and fire which are almost certain to occur if an unprotected aircraft is struck by lightning. The analysis should bring out clearly the questions on which further experimental work is needed and the assumptions that must be present to bridge the gaps regarding the phenomena associated with lightning.
Date: September 1943
Partner: UNT Libraries Government Documents Department

Protection of Nonmetallic Aircraft From Lightning 3: Electrical Effects in Glider Towlines

Description: Report presenting an exploration of the electrical effects that glider tows operating in or near a thunderstorm may experience. The three primary hazards are a direct lightning strike, a lightning strike that passes to some intermediate point on the towline, and an electrical current of appreciable magnitude flowing in the towline the whole time that the tow is within a few miles of the thunderstorm.
Date: March 1944
Partner: UNT Libraries Government Documents Department

Protection of Nonmetallic Aircraft From Lightning 4: Electrocution Hazards From Inductive Voltages

Description: Report presenting tests made on an XCG-7 all-wood glider on a PT-19A training airplane with a tubular metal fuselage and wooden wings by passing electrical surges simulating lightning discharges through the aircraft and measuring the voltage induced between various points which might be touched by an occupant. While certain recommendations for electrical protection are provided, the personnel in a metal fuselage aircraft are reasonably well protected from induced voltage shock without other protection.
Date: March 1945
Partner: UNT Libraries Government Documents Department