Control of an oblique shock/boundary-layer interaction with aeroelastic mesoflaps

Aeroelastic mesoflaps for recirculating transpiration have been investigated in an effort to control shock/boundary-layer interactions (SBLIs) through passive cavity recirculation. The mesoflap concept utilizes a matrix of small flaps covering an enclosed cavity that are designed to undergo local aeroelastic deflection to achieve proper mass bleed or injection when subjected to gasdynamic pressure loading. Experiments were performed to investigate the applicability of the mesoflap concept for oblique shock interaction by employing shadowgraph flow visualizations, surface pressure measurements, and mean and fluctuating velocity measurements, along the spanwise midplane of the shock intersection. The experiments were conducted in a Mach 2.41 supersonic wind tunnel operating at a unit Reynolds number of 57 x [10.sup.6] [m.sup.-1]. With the thickest mesoflap arrays in place, the leading shock formed at the location of the first flap and the boundary-layer thickness at shock impingement was greater due to flow injection through the upstream flaps. However, the thinnest mesoflap arrays yielded a somewhat reduced boundary-layer thickness downstream of the interaction as a result of the tangential bleeding by the last flaps. Stagnation pressure profiles for the thinnest arrays also showed improved recovery downstream of the SBLI as compared to the solid-wall case. However, further study is needed to investigate three-dimensional effects and to determine whether this control strategy provides significant performance improvements for flow conditions more consistent with actual inlets.