Direct Numerical Simulation of Acoustically-Driven Transition in a Hypersonic Wind Tunnel

View Video Presentation: https://doi.org/10.2514/6.2023-3555.vid This work studies the effects of facility noise on hypersonic transition using direct numerical simulation (DNS). A model for the freestream disturbance environment of a particular hypersonic wind tunnel is constructed from experimental measurements; the model is then used to simulate prior experiments performed in the same wind tunnel using a sharp cone and hollow cylinder. The computations demonstrate that introducing appropriately-modeled acoustic disturbances into the freestream via a body forcing term can replicate the experimental effects of facility noise. Calculations of surface heat flux indicate good experimental agreement with in prediction of transition location, and total temperature spectra extracted from the flow compare favorably with the experimental data. Visualizations of the flowfield confirm the onset of turbulence as a result of the freestream forcing. The computations also suggest that nonlinear interactions may be present in the turbulent breakdown region, leading to the production of streamwise streaks along the cone’s surface.