低雷诺数非线性k-ε湍流模型及其应用

An New Low-Reynolds-number Nonlinear k-εModel and Its Application

本文发展了一个低雷诺数非线性k-ε湍流模型,其特点是考虑了湍动能及湍动能耗散速度的非线性扩散过程,采用了一个非线性雷诺应力表达式,引入了壁面修正函数以考虑湍流的近壁低雷诺数效应.应用该模型计算了湍流槽流和湍流库埃特流.与实验结果的比较表明,所建模型对包括近壁区在内的整个计算域的各湍流量都能给出非常满意的预测结果.

A new low-Reynolds-number k-εmodel was developed in this paper. The main features of the model lie in consdering the nonlinear diffusive processes of turbulent kinetic energy and its dissipation rate, founding an nonlinear expression for the Reynolds stress, and incorporating two damping functions for compen-sating the effects of near-wall anisotropy. Then the model was applied to one channel flow and three Couette flows. The results obtained show that the turbulence quantities of above flows are in excellent agreement with experimental data. The anisotropy of turbulent intensities in the flow domains, especialy in the near-wall region, in which this anisotropy can not be predicted correctly by other similar k-εmodels, is also well reproduced.