Application of Radial-Equilibrium Condition to Axial-Flow Compressor and Turbine Design (open access)

Application of Radial-Equilibrium Condition to Axial-Flow Compressor and Turbine Design

"Basic general equations governing the three-dimensional compressible flow of gas through a compressor or turbine are given in terms of total enthalpy, entropy, and velocity components of the gas. Two methods of solution are obtained for the simplified, steady axially symmetric flow; one involves the use of a number of successive planes normal to the axis of the machine and short distances apart, and the other involves only three stations for a stage in which an appropriate radial-flow path is used. Methods of calculation for the limiting cases of zero and infinite blade aspect ratios and an approximate method of calculation for finite blade aspect ratio are also given" (p. 1).
Date: January 1, 1949
Creator: Wu, Chung-Hua & Wolfenstein, Lincoln
System: The UNT Digital Library
Laminar mixing of a compressible fluid (open access)

Laminar mixing of a compressible fluid

From Summary: "A theoretical investigation of the velocity profiles for laminar mixing of a high-velocity stream with a region of fluid at rest has been made assuming that the Prandtl number is unity. A method which involves only quadratures is presented for calculating the velocity profile in the mixing layer for an arbitrary value of the free-stream Mach number. Detailed velocity profiles have been calculated for free-stream Mach numbers of 0, 1, 2, 3, and 5."
Date: January 5, 1949
Creator: Chapman, Dean R.
System: The UNT Digital Library
Investigation with an interferometer of the turbulent mixing of a free supersonic jet (open access)

Investigation with an interferometer of the turbulent mixing of a free supersonic jet

The free turbulent mixing of a supersonic jet of Mach number 1.6 has been experimentally investigated. An interferometer, of which a description is given, was used for the investigation. Density and velocity distributions through the mixing zone have been obtained. It was found that there was similarity in distribution at the cross sections investigated and that, in the subsonic portion of the mixing zone, the velocity distribution fitted the theoretical distribution for incompressible flow. It was found that the rates of spread of the mixing zone both into the jet and into the ambient air were less than those of subsonic jets.
Date: January 21, 1949
Creator: Gooderum, Paul B.; Wood, George P. & Brevoort, Maurice J.
System: The UNT Digital Library
Fundamental effects of aging on creep properties of solution-treated low-carbon N-155 alloy (open access)

Fundamental effects of aging on creep properties of solution-treated low-carbon N-155 alloy

A method is developed whereby the fundamental mechanisms are investigated by which processing, heat treatment, and chemical composition control the properties of alloys at high temperatures. The method used metallographic examination -- both optical and electronic --studies of x-ray diffraction-line widths, intensities, and lattice parameters, and hardness surveys to evaluate fundamental structural conditions. Mechanical properties at high temperatures are then measured and correlated with these measured structural conditions. In accordance with this method, a study was made of the fundamental mechanism by which aging controlled the short-time creep and rupture properties of solution-treated low-carbon n-155 alloy at 1200 degrees F.
Date: January 18, 1949
Creator: Frey, D. N.; Freeman, J. W. & White, A. E.
System: The UNT Digital Library
Response of a Rotating Propeller to Aerodynamic Excitation (open access)

Response of a Rotating Propeller to Aerodynamic Excitation

"The flexural vibration of a rotating propeller blade with clamped shank is analyzed with the object of presenting, in matrix form, equations for the elastic bending moments in forced vibration resulting from aerodynamic forces applied at a fixed multiple of rotational speed. Matrix equations are also derived which define the critical speeds end mode shapes for any excitation order and the relation between critical speed and blade angle. Reference is given to standard works on the numerical solution of matrix equations of the forms derived" (p. 1).
Date: January 21, 1949
Creator: Arnoldi, Walter E.
System: The UNT Digital Library
Longitudinal Stability and Control Characteristics of a Semispan Wind-Tunnel Model of the XF7U-1 Airplane and a Comparison with Complete-Model Wind-Tunnel Tests and Semispan-Model Wing-Flow Tests (open access)

Longitudinal Stability and Control Characteristics of a Semispan Wind-Tunnel Model of the XF7U-1 Airplane and a Comparison with Complete-Model Wind-Tunnel Tests and Semispan-Model Wing-Flow Tests

An investigation was conducted on an 0.08-scale semispan model of the Chance Vought XF7U-1 airplane in the Langley high-speed 7- by 10-foot tunnel in the Mach number range from 0.40 to 0.97. The results are compared with those obtained with an 0.08-scale sting-mounted complete model tested in the same tunnel and with an 0.026-scale semispan model tested by the wing-flow method. The lift-curve slopes obtained for the 0.08-scale semispan model and the 0.026-scale wing-flow model were in good agreement but both were generally lower than the values obtained for the sting model.
Date: January 18, 1949
Creator: Goodson, Kenneth W. & King, Thomas J., Jr.
System: The UNT Digital Library
Present status of research on boundary-layer control (open access)

Present status of research on boundary-layer control

Report presenting a survey of the present status of research on boundary-layer control and its possible applications in aeronautics. The applications considered include reduction of profile drag by the elimination of turbulent separation, increase of the maximum lift coefficient through control of separation, use of suction and blowing slots near the trailing edge of the airfoil as a means of lateral control, use of boundary-layer control as a means of increasing the efficiency of diffusers and bends, and the use of boundary-layer control to influence shock-boundary-layer interaction at high speeds.
Date: January 12, 1949
Creator: von Doenhoff, Albert E. & Loftin, Laurence K., Jr.
System: The UNT Digital Library
Performance of Axial-Flow Supersonic Compressor on XJ-55-FF-1 Turbojet Engine 1: Preliminary Performance of Compressor (open access)

Performance of Axial-Flow Supersonic Compressor on XJ-55-FF-1 Turbojet Engine 1: Preliminary Performance of Compressor

An investigation was conducted to determine the performance characteristics of the axial-flow supersonic compressor of the XJ-55-FF-1 turbo Jet engine. The test unit consisted of a row of inlet guide vanes and a supersonic rotor; the stator vanes after the rotor were omitted. The maximum pressure ratio produced in the single stage was 2.28 at an equivalent tip speed or 1814 feet per second with an adiabatic efficiency of approximately 0.61, equivalent weight flow of 13.4 pounds per second. The maximum efficiency of 0.79 was obtained at an equivalent tip speed of 801 feet per second.
Date: January 30, 1949
Creator: Hartmann, Melvin J. & Graham, Robert C.
System: The UNT Digital Library