Computational Investigation of the Thermo-Fluid Mechanisms for Aero-Optical Distortions in a Subsonic Compressible Shear Layer

The spatial and temporal density variations that are characteristic of a compressible free shear layer give rise to significant optical aberrations, leading to a reduction of optical system performance. Previous experimental, computational, and analytical studies into the aero-optical effects of a compressible shear layer have shown disagreement in the magnitude of the shear layer density gradients and thus, the thermodynamic origins of such optical distortions. In this study, we leverage advanced turbulence modeling to effectively investigate the thermo-fluid interactions present in a compressible free shear layer and provide further insight into the driving mechanisms for the sharp spatial gradients that are present in instantaneous realizations of density and static temperature of the flow.