Passive Control of a Supersonic Shear Layer

Experiments have been performed to study the influence of an array of vortex generators on a supersonic shear layer. The goal of this study is to attenuate unwanted, unsteady density fluctuations for the purposes of improving aero-optical performance. For these experiments, a shear layer was generated from a backward-facing step. In these experiments, stereoscopic particle image velocimetry has been used to measure the shear layer and its turbulent quantities, to understand changes to the mean velocity profile and its Reynolds stress distribution. Additionally, power spectra are presented using a high-speed pressure sensor, located at the point where the shear layer reattaches to the floor. Together, these complementary measurements can help establish a quantitative foundation for characterizing the modified shear layer.