雷诺时均模拟的两种转捩模型比较  

Numerical Investigation of Transitional Flow by Applying Two Transitional Models for Reynolds Average Navier-Stokes Simulation

作　　者：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）》2014年第4期524-532,共9页Journal of East China University of Science and Technology

基　　金：国家自然科学基金资助项目(51176048)

摘　　要：对两种基于RANS方程的转捩模型进行分析讨论,这两个模型都只需采用局部变量计算,其中SST-γ-Reθt模型基于实验经验公式,层流动能模型基于转捩现象。两个模型都被耦合到RANS低雷诺数湍流模型中,并通过不同工况下T3系列平板的数值计算对模型进行评估。结果表明转捩模型较原湍流模型需要消耗更多计算资源;相对层流动能模型,SST-γ-Reθt模型对y+更为敏感,在无压力平板算例中两个模型能够较为准确地预测转捩,只有在湍流度增大时,SST-γ-Reθt模型预测的精度才会下降;在有压力梯度情况下,两个模型预测转捩起始点都较实验值延后,当来流雷诺数较大时层流动能模型预测的转捩长度较实验值偏小;从平板上不同位置(层流区、转捩区和湍流区)湍动能的分布情况能够看出SST-γ-Reθt模型只是在数值上模拟转捩过程,并不考虑转捩内在规律,层流动能模型预测结果与实验值较为吻合。This paper provides an analysis of two transition models which only use local variables, one is SST-γ-Reθt, model based on empirical equation from experiment, and the other is laminar kinetic energy model which applies additional laminar kinetic energy equations. These two models, which were embedded into the in-house RANS solver, are evaluated by numerical simulations of the flow around a series of T3 flat plates under different points. The results show that the calculation time of both models has increased nearly 50% compared to that of the original turbulence models. In the zero-pressure-gradient cases, the numerical results of both models agree well with the experiment data, while only in high turbulent intensity, the predicting accuracy of SST-γ-Reθt model reduces. In non zero-pressure gradient cases, the transition onset of both models slightly delay, as compared to the experiment data and the transition length of laminar kinetic energy model is shorter than the experiment result. The distribution of the kinetic energy at different position shows that SST-γ-Reθt model can numerically simulate the transition flow with no physical meaning, while the laminar kinetic energy model agrees well with the experiment data, which means that it can reveal part of the transition mechanism.

关 键 词：转捩流动 局部变量 RANS方程 层流动能 

分 类 号：O357.5[理学—流体力学]