Flow transition to turbulence and induced acoustics at Mach 6

This paper presents the results of implicit large eddy simulation (iLES) and direct numerical (DNS) for flow acoustics transitional turbulent boundary layer over a flat plate at Mach 6. The DNS was about 50 times more refined grid-wise than iLES. Both iLES were performed using same schemes, initial conditions. We compare different approaches concerning shape factor, momentum-thickness-based Reynolds number, heat flux on wall, stress, near-wall acoustics. perform pressure fluctuations spectral analysis propose predictive model. show that captures rather accurately acoustic characteristics in region. Differences up to 5 dB occur between transition also shifts slightly further downstream end underpredicts shear stress value peak. spectrum roll-off low medium frequencies. It high frequencies' content due grid constraints. Overall, gives excellent compared significantly DNS. high-order simulations can help adapt validate semi-empirical models engineering design loading hypersonic structures.