Accession Number : AD0265899

Title :   THE EXISTENCE OF THREE-DIMENSIONAL PERTURBATIONS IN THE REATTACHMENT OF A TWO-DIMENSIONAL SUPERSONIC BOUNDARY LAYER AFTER SEPARATION,

Corporate Author : ADVISORY GROUP FOR AERONAUTICAL RESEARCH AND DEVELOPMENT PARIS (FRANCE)

Personal Author(s) : Ginoux, Jean J.

Report Date : APR 1960

Pagination or Media Count : 18

Abstract : The reattachment region of a laminar boundary layer after separation has been investigated at a Mach number of 2.16. Two-dimensional compression corners and backward or forward facing step models were used. The case of interaction between a shock wave and a laminar boundary layer was also considered. Surface flow was observed by a sublimation technique and detailed span-wise surveys were made in the reattachment region of the flow with total-head probes. Strong, regular and repeatable span-wise perturbations were observed in the boundary layer; these could not be explained by irregularities either in the air flow upstream of the models or in the models themselves. It was found in all cases that street-like flow perturbations existedup to the point where transition occurred. A systematic investigation was made on backward facing steps in order to find out the effects of step height and boundary-layer thickness on the wave length of the flow perturbations. (Author)

Descriptors :   *PERTURBATION THEORY, *SUPERSONIC FLOW, BOUNDARY LAYER, EXPERIMENTAL DATA, LAMINAR BOUNDARY LAYER, PHOTOGRAPHIC ANALYSIS, STABILITY, TABLES(DATA), THREE DIMENSIONAL FLOW, TURBULENT BOUNDARY LAYER, WIND TUNNEL MODELS.

Distribution Statement : APPROVED FOR PUBLIC RELEASE