Detached-Eddy simulations of rocket plume noise at lift-off

The three-dimensional turbulent flow and acoustic field of a supersonic jet impinging on a solid plate at different inclination angles is studied computationally using the general-purpose CFD code ANSYS Fluent. A pressure-based coupled solver formulation with the second-order weighted central-upwind spatial discretization is applied. Hot jet thermal condition is considered. Acoustic radiation of impingement tones is simulated using a transient time-domain formulation. The effects of turbulence in steady state are modeled by the SST k- turbulence model. The Wall-Modeled Large-Eddy Simulation (WMLES) model is applied to compute transient solutions. The near-wall mesh on the impingement plate is fine enough to resolve the viscosity-affected near-wall region all the way to the laminar sublayer. Inclination angle of the impingement plate is parameterized in the model for automatic re-generation of the mesh and results. The transient solution reproduces the mechanism of impingement tone generation by the interaction of large-scale vortical structures with the impingement plate. The acoustic near field is directly resolved by the Computational Aeroacoustics (CAA) to accurately propagate impingement tone waves to near-field microphone locations. Results show the effect of the inclination angle on sound level pressure spectra and overall sound pressure level directivities.