Direct Numerical Simulation of Chemical Non-equilibrium Turbulent Flow

Temporally evolving high-temperature turbulent channel flows (at Ma_∞=6 and 10 and Re_∞=12000) are performed by using direct numerical simulation with the assumption of local thermal equilibrium and chemical non-equilibrium. The turbulent statistical characteristics are studied. We find that the Morkovin theory for the Van Direst transformed velocity remains valid, while the compressibility effects need to be considered since the turbulent Mach number is high enough, especially for the higher Mach number case. The dissociation/recombination reactions are excited, which are proved by the mean temperature, mass fractions and specific heat ratio. The importance of the mean property variations is studied from the rms velocity and mass fraction fluctuations.