Computation of Aero-Optical Distortions over a Cylindrical Turret with Passive Flow Control

Large-eddy simulations are performed for compressible flow over a cylindrical turret with a flat optical window, with and without passive control in the upstream boundary layer. Statistics of the flow field and optical distortions are computed and compared with experimental measurements. Results show reasonable agreement with experimental data for the baseline case without control. When passive control is applied using thin and tall pins, the numerical results confirm key experimental findings, although some quantitative discrepancies are observed. The flow simulated is characterized by two distinct shear layers above the optical window, whose combined effect leads to slightly reduced optical distortions compared to the uncontrolled flow with a single strong shear layer.