大曲率弯管中湍流的计算与模型考证  

Calculation of Turbulent Flow in a Strongly Curved Duct and Verification of Turbulence Models

作　　者：马坤[1] 杨金龙[1] 赖焕新[1] 

机构地区：[1]华东理工大学承压系统与安全教育部重点实验室,上海200237

出　　处：《华东理工大学学报（自然科学版）》2013年第5期617-624,共8页Journal of East China University of Science and Technology

基　　金：国家自然科学基金(51176048)

摘　　要：一些文献在使用标准k-ε模型预测弯道湍流时缺乏网格无关性检查和湍流参数的比对。本文结合具有详细测量数据的弯道湍流算例,研究了标准k-ε模型结合壁面函数法在不同网格密度时的计算结果。检查表明排除网格依赖性以后,标准k-ε模型与壁面函数法的结合使用可以获得明显优于前人的计算结果,即使是在弯道的后半段,计算结果仍然与实验数据良好地吻合。同时采用当前预测复杂流动时较受欢迎和好评的SST k-ω模型作比对分析,考证两种模型对曲率影响的预测能力。结果表明,SST k-ω模型对于弯道后半段的主流速度和二次流速度预测值优于标准k-ε模型,但对湍流动能和脉动应力的预测结果则显示标准k-ε模型在数值上与实验值更为接近,优于SST k-ω模型的结果。In some literatures, the standard k-ω turbulence model has been criticized in predicting flows in strongly curved ducts. However, checking of grid-dependency and turbulent parameters were often missing in those papers. In such a situation, a curved duct flow case which had benchmark experimental data was numerically calculated using four meshes. The standard k-ω model combined with a wall function was employed for closure of turbulence. Results show that after eliminating the grid-dependency, the predicted velocity fields by the standard k-s model can improve agreements with the experiments, compared with the previous calculations. Even in the second half of the bend, the present calculation agrees well with the experimental data. The SST k-o） model is also employed for comparison. The numerical results of streamwise and secondary velocities in the second half bend show better agreements with the experiments obtained by the SST k-ω model, while for the predicted turbulent fluctuating kinetic energy and stresses, better agreements are shown by the standard k-ω model.

关 键 词：弯管 湍流流动 标准肛￡模型 SST k-ω模型 

分 类 号：O357.5[理学—流体力学]