Mitigation of Optical Distortions in a Free Shear Layer Using Feedback Flow Control

The development of a flow-state database, including the optical aberrations caused by density variations, of the separated shear layer behind a backward-facing step is discussed in this paper. Delayed Detached-Eddy Simulations (DDES) using Cobalt are performed to investigate the flow field, both in its natural, unforced state and when periodic forcing is applied. The results indicate that the large, coherent structures in the shear layer cause the most severe optical aberrations, while the smaller scales do not significantly affect the beam. The computational results are part of a flow state database that will serve as the basis for the development of feedback control strategies to mitigate the optical aberrations caused by large coherent structures in the flow.