Local entropy production in turbulent shear flows: a high-Reynolds number model with wall functions

Entropy production in incompressible turbulent shear flows of Newtonian fluids is analysed systematically and incorporated into a CFD code. There are four different mechanisms of entropy production: dissipation in a mean and fluctuating velocity field and heat flux in a mean and fluctuating temperature field. Based on asymptotic considerations wall functions for the four production terms are developed. These wall functions are mandatory when high-Reynolds number turbulent models are used since peak values of entropy production occur in the immediate vicinity of a wall. As an example pipe flow with heat transfer is analysed and compared to results from a direct numerical simulation with special emphasis on the entropy production in the near wall region.