Unsteady Dynamics of a Single Nozzle Supersonic Retropropulsion Configuration

High-fidelity simulations of supersonic retropropulsion environments have been conducted using CRoCCo-AMR, a validated flow solver with curvilinear adaptive mesh refinement. The computational approach for simulating retropropulsion utilizing generalized curvilinear adaptive mesh refinement is discussed in detail. Results are presented for a single-nozzle condition at thrust coefficients of 0.5 and 2.0. Strong agreement is demonstrated in key regions of the flowfield with wind tunnel experiments conducted at the Unitary Plan Wind Tunnel at NASA Langley Reserach Center. Mean and statistical analyses are performed to characterize unsteady turbulence quantities present in the canonical retropropulsion environment. The findings herein suggest the presence of a dominant low-frequency modes along the forebody and aftbody of the vehicle show correlation with pressure fluctuations emanating from the primary vortex core where the jet and post-bowshock interaction region.