Validity studies of an improved low-Reynolds k-ε turbulence model applied to some practical problems

摘要

Apparent problem associated with the modeling of low Reynolds number wall damping functions used in the Low-Reynolds number models are examined critically and an improved version of the low Reynolds number k-ε model is proposed by defining the wall damping factors as a function of some quantity (turbulence Reynolds number ) that is only a rather general indicator of the degree of turbulent activity at any location in the flow rather than a specific function of the location itself, and by considering the wall limiting behavior, the free-stream asymptotic behavior, and the balance between production and destruction of turbulence. This model is applied to the prediction of transitional boundary layers influenced by the free-stream turbulence, favorable and adverse pressure gradient, and heat transfer. It is demonstrated that the present model yields improved predictions for the test cases.