Despite extensive studies on compressible turbulent channel flows (CTCFs) over the past few decades, two types of streamwise driving forces—the uniform body force and the density-weighted body force—have been inconsistently employed by different researchers. However, the impact of such discrepancy on numerical results remains poorly understood. In this paper, we conduct direct numerical simulations of CTCFs with symmetric isothermal cold walls and cases featuring one isothermal cold wall alongside one isothermal quasi-adiabatic wall, aiming to systematically and quantitatively compare the differences on turbulence statistics when applying these two types of driving forces. Our analysis focuses on mean momentum, energy, and vorticity transport, as well as ejection and sweeping events, to elucidate the observed variations. While the differences are minimal in symmetric channel flows, as noted by Huang et al. [J. Fluid Mech. 305, 185 (1995)], they become more significant and cannot be easily neglected when the flow exhibits strong compressibility or substantial wall temperature differences. These findings underscore the importance of carefully considering the choice of driving force in direct numerical simulations and analysis of thermodynamically asymmetric turbulent channel flows with sufficiently high Mach numbers or significant wall temperature differences.

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• Compressible turbulence
• Turbulence simulations