DOI: 10.1615/TSFP2
EFFECTS OF COMPRESSIBILITY AND FLUID PROPERTIES IN TURBULENT SUPERSONIC CHANNEL FLOW
SINOPSIS
Direct numerical simulations are performed in nominally fully developed channel flow at global Mach and Reynolds numbers of 1.5 and 3000. A pressure - velocity - entropy form of the compressible Navier - Stokes equations is integrated using a fifth order compact upwind scheme for the Euler part, a fourth order Pade scheme for the viscous terms and a third -order low - storage Runge - Kutta time integration method. Coleman et al.'s (1995) spectral DNS data of turbulent supersonic channel flow in air at M = 1.5 and Re = 3000 are used to check the accuracy of the method. Excellent agreement is obtained. The present work aims at increasing the insight into effects of compressibility beyond what has been explored by Coleman et al. (1995) and Huang et al. (1995). To this end the nature of fluctuating variables is investigated using scatter plots and transport equations, while the structural effects of compressibility are analysed based on the Reynolds stress budgets and comparisons with their incompressible counterparts. DNS data of turbulent supersonic channel flow in CO2 at M = 1.5 and Re = 3000 are used to reveal the effect of thermodynamic properties on mean flow quantities and the turbulence structure.