An experimental investigation of the ELAC 1 configuration at supersonic speeds

Supersonic flight of aerospace planes is of marked interest since several f low regimes characterized by different local flow structures have to be flo wn through. This problem was investigated experimentally for the hypersonic research configuration ELAC 1. The aim of the study was to detect the infl uence of the rounded leading edge, of the thickness distribution prescribed , and of the Reynolds number, especially on the flow on the leeward side of the configuration. The experiments were carried out in the transonic wind tunnel of Aerodynamisches Institut of RWTH Aachen, at a freestream Mach num ber Ma(infinity) = 2, a unit Reynolds number of Re-infinity = 13 x 10(6), a ngles of attack between - 3 degrees less than or equal to alpha less than o r equal to 10 degrees, and in a wind tunnel of the Institute for Theoretica l and Applied Mechanics of the Russian Academy of Sciences in Novosibirsk. The freestream Mach numbers covered in these experiments were varied betwee n 2 less than or equal to Ma(infinity) less than or equal to 4, freestream Reynolds numbers per unit length between 25 x 10(6) less than or equal to R e-infinity less than or equal to 56 x 10(6) and angles of attack between -3 degrees less than or equal to alpha less than or equal to 10 degrees. Flow visualization studies, measurements of surface pressure distributions and of aerodynamic forces were used to analyze the flow. The results, which wil l also be compared with numerical data, clearly indicate marked differences in the location of the separation and reattachment lines, and the formatio n of the primary, secondary and tertiary vortices, for the flow regimes inv estigated.