CONSISTENT INITIAL CONDITIONS FOR THE DNS OF COMPRESSIBLE TURBULENCE

Relationships between diverse thermodynamic quantities appropriate to weakly compressible turbulence are derived. It is shown that for turbu lence of a finite turbulent Mach number there is a finite effect of co mpressibility. A methodology for generating initial conditions, consis tent with finite Mach number, fur the fluctuatiug pressure, density, a nti dilatational velocity is given. Use of these initial conditions gi ves rise to a smooth development of the flow, in contrast to cases in which these fields are specified arbitrarily or set to zero. Compariso ns of the effect of different types of initial conditions are made usi ng direct numerical simulation of decaying isotropic turbulence. (C) 1 997 American Institute of Physics.