一种基于湍流模式的转捩预测方法

Study of numerical method for flow transition prediction based on turbulence model

通过对平板边界层进行计算分析,基于湍流模式来预测流动转捩是可行的,但预测出的转捩位置不准,比实际情况靠前。因此,本文从转捩流动的物理特征出发对湍流模式中的混合尺度作出了修正,提出了一种考虑间歇函数影响的k-ωSST两方程湍流模式。采用该模式来对平板湍流边界层和不同攻角下的NACA0012翼型绕流进行了转捩预测,计算结果表明,改进后的模式对转捩位置具有较好的预测能力。

Numerical method based on turbulonce model to predict flow transition is studied. By using k-ω SST two-equation model to simulate the fiat plate boundary layer, it is shown that the k-ω SST model can capture the transition phenomona but the predicted transition point is far prior to the measured position. So, the mixing length scale in the k-ω SST model is modified according to the characteristic of transition flow and a modified k-ω SST two-equation model taking account of intermittence function effect is put forward. By using this modified k-ω SST model to simulate the fiat plate boundary layer and the flow past NACA0012 at different incidences, it is seen that rational results are obtained and the modified model can predict the transition position with certain accuracy.