International Journal of Heat and Mass Transfer, Vol.40, No.3, 613-625, 1997
A Temperature Wall Function Formulation for Variable-Density Turbulent Flows with Application to Engine Convective Heat-Transfer Modeling
A temperature wall function was derived for variable-density turbulent flows that are commonly found in internal combustion engines. Thermodynamic variations of gas density and the increase of the turbulent Prandtl number in the boundary layer are included in the formulation. Multidimensional computations were made of a pancake-chamber gasoline engine and a heavy-duty diesel engine under firing conditions. Satisfactory agreement between the predicted and measured heat fluxes was obtained. It was found that gas compressibility affected engine heat transfer prediction significantly while the effects of unsteadiness and heat release due to combustion were insignificant for the cases considered.
Keywords:COMBUSTION