基于S-A湍流模型和间歇因子输运方程的转捩流数值模拟

考虑到γ-Re_θt转捩模型中间隙因子输运方程并不依赖于具体的湍流模型,因而提出了耦合S-A湍流模型和间歇因子输运方程的转捩流模拟方法.其主要思想是构造与间歇因子相关的两个耦合函数,分别作用到S-A模型的生成项和耗散项用以控制湍流的产生与发展,从而实现层流到湍流的数值转捩.结果表明:该方法中模型方程具有完全当地性的特点,易于实施,可直接用以求解三维转捩流动.4个典型算例表明该方法模拟结果与γ-Re_θt模型准确度相当,但少求解了两个输运方程,计算耗时减少了15%. 

Numerical simulation of transition flows based on S-A turbulence model and intermittency transport equation

Considering the intermittency transport equation in γ-Re_θt model independent of a specified turbulence model, a numerical simulation method for transitional flow by coupling the S-A turbulence model with intermittency transport equation was proposed. To control the generation and development of turbulence, two coupled functions related to the intermittency were applied on the production and destruction terms of S-A model respectively. As the model equations are local type, they can be easily implemented into an existent CFD code and 3-D transitional flows can also be solved directly. Four typical test cases indicate that the presented model has the equal accuracy as γ-Re_θt model. And due to pruning of two equations, the current model can decrease 15% time cost.