不可压湍流流动K-ε两方程模型参数辨识

Parameter identification of two-equation K-ε model for incompressible turbulent flow

本文提出了不可压湍流流动情况下标准 K -ε两方程模型的参数辨识方法 ,并对轴对称管道流动、二维后向台阶流动、轴对称突扩管道流动下的模型参数进行了参数辨识与分析 ,得到了一些初步结论 :( 1)参数辨识方法是确定湍流模型经验参数值的一种有效方法 ;( 2 )参数辨识结果受数值计算精度和流动特性影响很大 ;( 3)由于标准 K -ε两方程模型本身还有缺陷 。

In this paper, the parameter identification method is introduced to determine the parameters in the standard two equation K ε turbulence model for incompressible turbulent flow. By applying this method to the axisymmetric channel flow, backward facing step flow, and axisymmetric expansion channel flow, some preliminary conclusions can be drawn. First, the parameter identification method is an effective means to determine the parameters in the turbulence model. Second, the result is greatly influenced by numerical accuracy and the flow characteristics. Finally, it is too difficult to obtain a group of parameter values suiting for all kinds of separated flows due to some intrinsic defects in the Kε model structure.