Compressibility eects and turbulence scalings in supersonic channel ow

Turbulence in supersonic channel ow is studied using direct numerical simulation. The ability of outer and inner scalings to collapse proles of turbulent stresses onto their incompressible counterparts is investigated. Such collapse is adequate with outer scaling when suciently far from the wall, but not with inner scaling. Compressibility eects on the turbulent stresses, their anisotropy, and their balance equations are identied. A reduction in the near-wall pressure\u85strain, found responsible for the changed Reynolds-stress proles, is explained using a Greens-function-based analysis of the pressure eld. 1