Contributions on the Mechanics of Boundary-Layer Transition (open access)

Contributions on the Mechanics of Boundary-Layer Transition

"The manner in which flow in a boundary layer becomes turbulent was investigated on a flat plate at wind speeds generally below 100 feet per second. Hot-wire techniques were used, and many of the results are derived from oscillograms of velocity fluctuations in the transition region. Following a presentation of the more familiar aspects of transition, there are presented the very revealing facts discovered while studying the characteristics of artificially produced turbulent spots" (p. 853).
Date: February 28, 1955
Creator: Schubauer, G. B. & Klebanoff, P. S.
System: The UNT Digital Library
Friction, wear, and surface damage of metals as affected by solid surface films (open access)

Friction, wear, and surface damage of metals as affected by solid surface films

"As predicted by friction theory, experiments showed that friction and surface damage of metals can be reduced by solid surface films. The ability of materials to form surface films that prevent welding was a very important factor in wear of dry and boundary lubricated surfaces. Films of graphitic carbon on cast irons, NiO on nickel alloys, and FeO and Fe(sub 3)O(sub 4) on ferrous materials were found to be beneficial. Abrasive films such as Fe(sub 2)O(sub 3) or MoO(sub 3) were definitely detrimental. It appears that the importance of oxide films to friction and wear processes has not been fully appreciated" (p. 93).
Date: February 10, 1955
Creator: Bisson, Edmond E.; Johnson, Robert L.; Swikert, Max A. & Godfrey, Douglas
System: The UNT Digital Library
On the Kernel function of the integral equation relating lift and downwash distributions of oscillating wings in supersonic flow (open access)

On the Kernel function of the integral equation relating lift and downwash distributions of oscillating wings in supersonic flow

From Summary: "This report treats the Kernel function of the integral equation that relates a known or prescribed downwash distribution to an unknown lift distribution for harmonically oscillating wings in supersonic flow. The treatment is essentially an extension to supersonic flow of the treatment given in NACA report 1234 for subsonic flow. For the supersonic case the Kernel function is derived by use of a suitable form of acoustic doublet potential which employs a cutoff or Heaviside unit function. The Kernel functions are reduced to forms that can be accurately evaluated by considering the functions in two parts: a part in which the singularities are isolated and analytically expressed, and a nonsingular part which can be tabulated."
Date: February 15, 1955
Creator: Watkins, Charles E. & Berman, Julian H.
System: The UNT Digital Library
The Compressible Laminar Boundary Layer with Heat Transfer and Arbitrary Pressure Gradient (open access)

The Compressible Laminar Boundary Layer with Heat Transfer and Arbitrary Pressure Gradient

"An approximate method for the calculation of the compressible laminar boundary layer with heat transfer and arbitrary pressure gradient, based on Thwaites' correlation concept, is presented. With the definition of dimensionless shear and heat-transfer parameters and an assumed correlation of these parameters in terms of a momentum parameter, a complete system of relations for calculating skin friction and heat transfer results. Knowledge of velocity or temperature profiles is not necessary in using this calculation method" (p. 1).
Date: February 1, 1955
Creator: Cohen, Clarence B. & Reshotko, Eli
System: The UNT Digital Library