A comparative study of heat transfer characteristics of wall jet with boundary layer transition using six low-Reynolds number k–ε models

Abstract

A Low-Reynolds Number (LRN) k–ε model can well simulate the transition characteristics of the momentum boundary layer, but so far, there are few studies on the influence of boundary layer transition on heat transfer characteristics by using the LRN k–ε model. Due to the larger degree of flexibility and controllability of flow parameters than the conventional boundary layer, a wall jet is an ideal flow configuration to research the transition of the boundary layer. To investigate the performance of the LRN k–ε model in simulating the heat transfer characteristics of the wall jet with boundary layer transition, six versions of LRN k–ε models are used to simulate a three-dimensional wall jet with boundary layer transition and the computational results were compared with experimental data. It is found that the Abe–Kondoh–Nagano (AKN) and Yang–Shih (YS) models can accurately simulate the flow field and heat transfer of the laminar boundary layer due to the use of the Kolmogorov scale in the developing region. Compared with the YS model, the AKN model is capable of predicting the influence of boundary layer transition on the heat transfer process in good agreement with experimental results over the whole domain. From the calculation results, it is found that Abid and Change and Hsieh and Chen models are more appropriate for simulating the heat transfer in the fully turbulent region of the wall jet. The damping function fµ of the Lam–Bremhorst and Launder–Sharma models approaches a constant value near the wall, which does not meet the wall limiting conditions and leads to a negative impact on the simulation of heat transfer near the wall.