Establishment of an enhanced wall function using the heat transfer analogy method for internal combustion engines

Abstract

The thermal wall function method offers an effective pathway for modeling heat transfer in engines. This paper reexamined the traditional construction method of the thermal wall function and improved it by correcting the integration scheme in the boundary layer; then, an enhanced heat transfer model was introduced. Since the heat release from the chemical reactions is of great significance to the near-wall flow, it is necessary to construct a law of the wall including the heat release effect. A new law of the wall including the impacts of the pressure work and the heat release from chemical reactions was obtained based on the analogy between the momentum transfer and the heat transfer predicted using the improved thermal wall function. In the analogy process, the formula of the eddy-viscosity ratio was reconstructed for the whole boundary layer, and then, the Prandtl number for turbulent flow was improved. The current research is beneficial for predicting the near-wall flow and heat transfer characteristics under conditions with strong interactions between the wall and the flame.