Accession Number : AD0262031

Title :   LEADING EDGE EFFECT ON SEPARATED SUPERSONIC FLOWS

Corporate Author : CENTRE NATIONAL D'ETUDES ET DE RECHERCHES AERONAUTIQUES BRUSSELS (BELGIUM)

Personal Author(s) : GINOUX,JEAN J.

Report Date : MAY 1961

Pagination or Media Count : 1

Abstract : IN SUPERSONIC TUNNEL TESTS WITH A TWO-DIMENSIONAL BACKWARD-FACING STEP MODEL, SPAN-WISE PERTURBATIONS WERE FOUND IN THE REATTACHMENT REGION. Studies were made using the same and other similar models. In these later studies, the same three-dimensional perturbations were detected, into the full thickness of the boundary-layer, after reattachment, both in turbulent and laminar regions of the flow. Their amplitude was a maximum in the transition region. Using a model with a much improved accuracy of manufacture, notably at the leading-edge, it was found that the amplitude of the perturbations was greatly reduced, roughly in proportion to the size of the irregularities of manufacture of the leadingedge itself. It is concluded that the phenomenon is essentially one of instability in the twodimensional flow, the main triggering action arising from small irregularities in the leadingedge. (Author)

Descriptors :   *AERODYNAMIC CHARACTERISTICS, *AERODYNAMIC CONFIGURATIONS, AIRFOILS, FLUID MECHANICS, GAS FLOW, LAMINAR BOUNDARY LAYER, SUPERSONIC FLOW, SUPERSONIC WIND TUNNELS, WIND TUNNEL MODELS

Distribution Statement : APPROVED FOR PUBLIC RELEASE