Turbulence and Shear Flow Phenomena -1 First International Symposium

ISBN Print: 1-56700-135-1

COMPRESSIBILITY EFFECTS ON SHOCK-TURBULENCE INTERACTION

Abstract

Direct Numerical Simulation (DNS) and inviscid linear analysis (LIA) are used to study the interaction of a nor-mal Mach 1.5 shock wave and isotropic turbulence. The influence of the nature of the incoming turbulence on the interaction is emphasized. The presence of upstream entropy fluctuations enhance the amplification of the turbulent kinetic energy and transverse vorticity variance across the shock compared to the solenoidal (pure vorticity) case. More reduction of the transverse Taylor microscale is also observed in the vorticity-entropy case while no influence can be seen on the longitudinal microscope. When acoustic and vortical fluctuations are associated upstream, less amplification of the kinetic energy, less reduction of the transverse microscale and more amplification of the transverse vorticity variance are observed through the discontinuity. Most of these effects have been reported previously by different authors using different numerical codes. In our case, all calculations are conducted with the same numerical tool and similar flow parameters, so that the observed influence of upstream turbulence cannot be attributed to differences in the numerics. AH the DNS results are in good qualitative agreement with LIA.