气膜冷却计算中湍流黏性系数的修正  

Improved Eddy-Viscosity Modelling of Film Cooling Flows

作　　者：李雪英[1] 任静[1] 蒋洪德[1] 

机构地区：[1]清华大学热能工程系,北京100084

出　　处：《工程热物理学报》2011年第4期573-576,共4页Journal of Engineering Thermophysics

基　　金：国家973项目(No.2007CB210100)

摘　　要：燃气轮机高温叶片气膜冷却中的复杂涡系结构使得流动传热很难被准确预测。本文基于平板气膜冷却数值和实验研究结果,指出雷诺平均算法中常用的湍流模型在射流侧向输运和二次涡的捕捉上具有相当的局限性。文中对湍流黏性系数提出了各向异性对数率涡黏模型(ALEV模型)修正,基于ALEV模型修正后的湍流模型增强了射流的侧向输运,减弱了二次涡的强度,得到的结果与实验有较好的吻合度。经过验证,ALEV模型具有较高的可靠性,它为这一类流动传热计算的改善提供了可借鉴的途径。The unsteady coherent structure is typical in the flow field of the film cooling system in the industrial gas turbines.The sophisticated anisotropic structure is a knot for an accurate numerical algorithm.The comparison between the computation and experiment results of a flat plate film cooling in this study shows that the traditional eddy-viscosity based RANS turbulent models have a considerable limitation on the capture of the lateral spreading and the secondary vortices in the jet.Therefore,an Anisotropic Logarithm Eddy Viscosity（ALEV） model is presented based on anisotropic correction of the eddy viscosity term.The turbulent model improved by ALEV model enhances the lateral transport of the jet and reduces the strength of the vortices.The results show a good agreement with the experiment.The ALEV model provides a perspective way for numerical improvement of film cooling.

关 键 词：气膜冷却 湍流涡黏系数 湍流普朗特数 各向异性修正 

分 类 号：TK474.7[动力工程及工程热物理—动力机械及工程]