两种k-ε模型用于扩压器内流数值模拟的比较

A COMPARISION BETWEEM NUMERICAL SIMULATIONS OF 2 D DIEEUSER WITH TWO k ε MODELS

同时采用标准ｋ－ε及非线性ｋ－ε模型在附体坐标系下求解定常不可压Ｎ－Ｓ方程组计算扩压器内湍流流场，得到了扩压器的压力恢复系数和速度分布，与实验结果对比发现非线性ｋ－ε模型预测的结果更吻合实验值，且能测出临界扩压角下的局部分离流。文中着重研究了非对称扩压器，并给出了用两种模型计算的湍流量。

In order to solve steady N S equations,c onsidering the complexity of the diffuse r flow field,the flow can be treated as two dimensional due to large ratio of wi dth to high of the diffuser.From the com parison of calculation results with expe rimental data we find that the non linea r k ε model is better than the standard k ε model in predicting of pressure reco very and velocity distribution whether t here is flow separation or not in the fl ow field.The non linear k ε model can pr edict local separation at critical diver gent angle.As the rate of non linear dis tortion is included in the non linear k ε model which describes non homogeneous of turbulent fluctuating parameters,the non linear k ε model is suitable to more complicated flow field.The turbulent in tensity and the turbulent energy distrib ution in an asymmetrical diffuser are al so given by using two k ε models.