Accession Number : AD0686443

Title :   INHIBITION OF FLOW SEPARATION AT HIGH SPEED. VOLUME I. SUPERSONIC TURBULENT BOUNDARY LAYERS.

Descriptive Note : Technical documentary rept. Oct 66-Sep 68,

Corporate Author : NIELSEN ENGINEERING AND RESEARCH INC PALO ALTO CALIF

Personal Author(s) : Lynes,Larry L. ; Nielsen,Jack N. ; Goodwin,Frederick K.

Report Date : MAR 1969

Pagination or Media Count : 68

Abstract : The method of integral relations was successfully applied to compressible nonadiabatic turbulent boundary layers on a flat plate. The theory is designed to accept any desired eddy-viscosity model. A particular eddy-viscosity model was incorporated into the method, and the equations were programmed for application to a flat plate with no pressure gradient. The variations of the skin-friction coefficient with Reynolds number, Mach number, and temperature ratio were calculated using this program, and the results are in good accord with similar results calculated by the Spalding-Chi method and the Rubesin T' method. An analysis was made to predict to what extent turbulent separation of the free-interaction type can be inhibited by means of surface cooling. It was observed experimentally that free-interaction is applicable to separated turbulent boundary layers up to the separation point or beyond. The free-interaction model used in the analysis is based on adding the boundary-layer displacement thickness to the actual body dimensions in calculating the induced pressures. The critical temperature ratios calculated on this basis are generally greater than adiabatic wall temperature except in the supersonic range up to a Mach number approaching 3, where moderate cooling is required to inhibit separation. (Author)

Descriptors :   (*FLOW SEPARATION, INHIBITION), (*TURBULENT BOUNDARY LAYER, SUPERSONIC CHARACTERISTICS), FLAT PLATE MODELS, INTEGRAL EQUATIONS, COMPRESSIBLE FLOW, VISCOSITY, SKIN FRICTION, REYNOLDS NUMBER, INTERACTIONS, THERMODYNAMICS

Subject Categories : Aerodynamics
      Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE