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Preliminary investigation of the supersonic flow field downstream of wire-mesh nozzles in a constant-area duct / Lawrence I. Gould

Description: An investigation was conducted in a 3.4- by 3.4-inch duct to determine the characteristics of the supersonic flow downstream of four wire-mesh screen nozzles with nominal design Mach numbers in the range between 1.97 and 2.58. Two types of disturbances were observed in the flow field: a fine network of interacting expansion and compression waves which were formed immediately downstream of the screens and appeared to dissipate within 25 to 40 wave intersections; and relatively strong oblique shock waves that originated at the junctions of the screens and the walls and were reflected throughout the length of the duct. Regions of fairly uniform flow were found to exist. The total-pressure loss across the screens varied from 22 percent at Mach number 1.58 to 43 percent at Mach number 2.06.
Date: August 14, 1951
Creator: Gould, Lawrence I
Partner: UNT Libraries Government Documents Department

A Preliminary Investigation of Triassic Rocks in the Lukachukai Mountains, Arizona

Description: Abstract: During the summer of 1955, two test holes were drilled into the Triassic Chinle Formation in the Lukachukai Mountains near Cove, Arizona, to obtain geologic information. Brief airborne and ground reconnaissance was made of Triassic outcrops near Cove. No anomalous radioactivity was found in the test holes, but chemical tests showed concentrations of heavy metals in conglomerate lenses in the Chinle Formation. Channel sandstones in the middle part of the Petrified Forest Member appear to be the most favorable for mineralization. The Shinarump Member, here underlain by a permeable unit, and occurring at depths greater than 500 feet, appears less promising for uranium exploration.
Date: December 3, 1956
Creator: Kosatka, Raymond F.
Partner: UNT Libraries Government Documents Department

Preliminary investigation of use of conical flow separation for efficient supersonic diffusion

Description: Use of flow separation on a rod projecting upstream of a blunt body to decelerate the supersonic stream ahead of an annular nose inlet was investigated at Mach numbers of 1.76, 1.93, and 2.10. Maximum pressure recoveries were obtained with rod tip projections about 1.5 times the radius of the spherical nose and were higher than those obtained with single-shock solid cones. Subcritical operation was similar to that observed with solid-cone inlets, but the effect of angle of attack on maximum pressure recovery was more severe.
Date: December 17, 1951
Creator: Moeckel, W E & Evans, P J , Jr
Partner: UNT Libraries Government Documents Department

Preliminary investigation on boundary layer control by means of suction and pressure with the U.S.A. 27 airfoil

Description: The tests described in this report constitute a preliminary investigation of airfoil boundary layer control, as carried out in the atmospheric wind tunnel of the Langley Memorial Aeronautical Laboratory, from February to August, 1927. Tests were made on a U.S.A. 27 airfoil section with various slot shapes and combinations, and at various amounts of pressure or suction on the slots. The lift of airfoils can be increased by removing or by accelerating the boundary layer. Removing the boundary layer by suction is more economical than to accelerate it by jet action. Gauze-covered suction slots apparently give the best results. When not in operation, all suction slots tested had a detrimental effect upon the aerodynamic characteristics of the airfoil which was not apparent with the backward-opening pressure slots. Thick, blunt-nose airfoils would seem to give best results with boundary layer control.
Date: May 1, 1928
Creator: Reid, E G & Bamber, M J
Partner: UNT Libraries Government Documents Department

Preliminary investigation to determine propeller section characteristics by measuring the pressure distribution on an NACA 10-(3)(08)-03 propeller under operating conditions

Description: An investigation has been made in the Langley 16-foot high-speed tunnel to determine the propeller-section characteristics by measuring the pressure distribution on the airfoil sections of a rotating propeller. The pressures were measured at nine radial stations on an NACA 10-(3)(08)-03 design two-blade propeller. This paper presents the results of the pressure measurements in the form of normal-force and moment coefficients and covers a range of nominal angle of attack (simple blade element theory) from 0 degrees to 4 degrees for a section Mach number range of approximately 0.6 to 1.15 for the outboard stations and approximately 0.3 to 0.6 for inboard stations.
Date: July 14, 1948
Creator: Evans, Albert J & Liner, George
Partner: UNT Libraries Government Documents Department

Preliminary Low-Speed Wind-Tunnel Investigation of Some Aspects of the Aerodynamic Problems Associated with Missiles Carried Externally in Positions Near Airplane Wings

Description: A low-speed wind-tunnel investigation has been made of some aspects of the aerodynamic problems associated with the use of air-to-air missiles when carried externally on aircraft. Measurements of the forces and moments on a missile model for a range of positions under the mid-semispan location of a 45deg sweptback wing indicated longitudinal and lateral forces with regard to both carriage and release of the missiles. Surveys of the characteristics of the flow field in the region likely to be traversed by the missiles showed abrupt gradients in both flow angularity and in local dynamic pressure. Through the use of aerodynamic data on the isolated missile and the measured flow-field characteristics, the longitudinal forces and moments acting on the missile while in the presence of the wing-fuselage combination could be estimated with fair accuracy. Although the lateral forces and moments predicted were qualitatively correct, there existed some large discrepancies in absolute magnitude.
Date: December 27, 1954
Creator: Alford, William J., Jr.; Silvers, H. Norman & King, Thomas J., Jr.
Partner: UNT Libraries Government Documents Department