Accession Number : ADP006050

Title :   Driving Mechanism of Unsteady Separation Shock Motion in Hypersonic Interactive Flow,

Corporate Author : TEXAS UNIV AT AUSTIN DEPT OF AEROSPACE ENGINEERING AND ENGINEERING MECHANICS

Personal Author(s) : Dolling, D. S. ; Narlo, J. C., II

Report Date : NOV 1987

Pagination or Media Count : 12

Abstract : Wall pressure fluctuations have been measured under the unsteady separation shock wave in Mach 5 turbulent interactions induced by unswept circular cylinders on a flat plate. The wall temperature was adiabatic. A conditional sampling algorithm has been developed to examine the statistics of the shock wave motion. The same algorithm has been used to examine data taken in earlier studies in the Princeton University Mach 3 blowdown tunnel. In these earlier studies, hemicylindrically blunted fins of different leading-edge diameters were tested in boundary layers which developed on the tunnel floor and on a flat plate. A description of the algorithm, the reasons why it was developed and the sensitivity of the results to the threshold settings, are discussed. The results from the algorithm, together with cross correlations and power spectral density estimates suggests that the shock motion is driven by the low-frequency unsteadiness of the downstream separated, vortical flow.

Descriptors :   *HYPERSONIC FLOW, *FLOW SEPARATION, SHOCK WAVES, UNSTEADY FLOW, FINS, BLUNT BODIES, LEADING EDGES, ADIABATIC CONDITIONS, VORTICES, DOWNSTREAM FLOW, SYMPOSIA.

Subject Categories : Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE