Accession Number : AD0646743

Title :   EXPERIMENTAL INVESTIGATION OF THE DENSITY FLOW FIELD IN THE STAGNATION REGION OF A BLUNT BODY IN HIGH SPEED RAREFIED FLOW,

Corporate Author : CELESTIAL RESEARCH CORP SOUTH PASADENA CALIF

Personal Author(s) : Wainwright,J. B.

Report Date : NOV 1966

Pagination or Media Count : 72

Abstract : The evolution of shock structure in the stagnation region of spheres was experimentally investigated in air and nitrogen flows at normal Mach number 6 and a Reynolds number range, based on sphere radius and viscosity behind a shock, between 1.7 and 69. The electron beam fluorescence technique was used to measure density in the region between the surface and one radius away from the surface and at angular displacements up to 40 degrees from the stagnation line. Model wall temperatures were held at adiabatic and .28 of adiabatic. Results at the lowest Reynolds number show agreement with free molecule theory when modified to account for single collisions between free stream molecules and those emitted from the model. As density is increased a progressively longer mean free path than that calculated for the free stream and emitted molecules is required to correlate the data. At Re sub s of 20 a shock structure begins to appear but is completely merged with the body influence. The maximum slope thickness of the primitive shock, relative to the mean free path behind the fully developed shock, ranges from 70% to 92% of the fully developed shock thickness for 12 < Re sub s < 69. (Author)

Descriptors :   (*RAREFIED GAS DYNAMICS, BLUNT BODIES), (*STAGNATION POINT, FLOW FIELDS), (*FLOW FIELDS, *BLUNT BODIES), DENSITY, HIGH ALTITUDE, FLIGHT, SHOCK WAVES, AIR, NITROGEN

Subject Categories : Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE