湍流应力输运方程中Π_(ij)和ε_(ij)的模型在旋转流动中的应用研究

TURBULENCE CLOSURE MODELS OF Π_ij & ε_ij AND APPLICATION TO A CONFINED SWIRLING FLOW

基于本文作者先前提出的构筑湍流应力输运方程中速度压力关联项Πij和耗散项εij的模型的一般途径[Proc．ofICFM－III，BITPress，1998]，本文推出了它的一个可用于三维流动的简化形式，计算了一个有旋绕的轴对称突扩管道内部流动．由于加入了湍流结构的上游边界条件，新模型对平均流场和Reynolds应力分量的预测比基本的微分应力模型（BRSM）有明显的改进．本文还对在手头没有真实的边界条件可用时，在各种常见的情况下如何加入湍流结构的边界条件作了初步的讨论．

A new modeling approach of the Reynolds stress transport equation was proposed by the present author [Proc. of ICFM-III, BIT Press, 1998]. Based on it, a simplified form of the model which can be used in 3D flow is newly proposed in the paper. A turbulent swirling flow through an abrupt axisymmetric expansion was calculated to examine the new model. It is shown that the boundary conditions of turbulence structure are essential to correctly predict the main feature, e.g. the size of recirculation area and the turbulent shear stress, of a complex turbulent internal flow. Finally, how to estimate the boundary conditions of the turbulent structure at different cases has briefly been discussed.