Wall pressure fluctuations in wall heated and cooled shock wave and turbulent boundary layer interactions

Wall pressure fluctuations in shock wave and turbulent boundary layer interactions on heated and cooled walls are investigated by performing direct numerical simulations. The objectives of this study are to identify flow dynamics causing low- and high-frequency wall pressure fluctuations and evaluate wall heating and cooling effects on the wall pressure fluctuations. The wall pressure spectra highlight two characteristic low-frequency spectral peaks at the separation point and below the expansion waves. Conditional analysis reveals that the two spectral peaks originate from the oscillations of the reflected shock and expansion waves, coupled with the expansion and contraction motions of the separated turbulent shear layer. Regarding wall temperature effects, wall cooling enhances the magnitude of the wall pressure fluctuations regardless of the low- and highfrequency components. Furthermore, influences of the expansion waves are also enhanced by wall cooling, which increases the wall pressure fluctuations locally after the separation.

Automated summary

Wall pressure fluctuations in shock wave and turbulent boundary layer interactions on heated and cooled walls are investigated. The study identifies flow dynamics causing low- and high-frequency wall pressure fluctuations and evaluates wall heating and cooling effects on the wall pressure fluctuations. The results show that there are two characteristic low-frequency spectral peaks in the wall pressure spectra, which originate from oscillations of the reflected shock and expansion waves combined with the motion of the separated turbulent shear layer. Wall cooling enhances the wall pressure fluctuations regardless of the frequency components, and also increases the influence of expansion waves on the wall pressure fluctuations after separation.