半封闭狭缝湍流冲击射流的数值模拟

Numerical Simulation of a Semi-Confined Slot Turbulent Impinging Jet

将Yakhot和Orszag提出的RNGk ε模型推广应用于半封闭狭缝冲击射流场的数值模拟 ,以评价该模型对这种复杂湍流的预测能力。将计算得到的流场平均速度分布、湍流强度分布和流函数分布与标准k ε模型的预测结果以及相应的实验数据进行了比较 ,结果表明 :RNGk ε模型的预测结果总体上要好于标准k ε模型 ,但与实验值相比 ,所有预测结果都还存在不同程度的误差 ,尤其是近壁区和滞止点较远下游处的湍流强度分布。说明RNG模型虽然已在某些湍流的预测中取得了一定的成功 ,但要定量准确地预测冲击射流场 。

An RNG based k ε model derived by Yakhot and Orszag is extended to the numerical simulation of a semi confined slot turbulent impinging jet flow in order to assess the model's predictive capability for complex turbulence flows. Computational results, which involve the mean velocity profiles, the turbulent intensity profiles and the stream function contours, are compared with those from the standard k ε model and with the corresponding experimental data. It is shown that the RNG k ε model is generally better than the standard k ε model. However, to some extent, there are differences between all results predicted by the RNG k ε model and the experimental data, especially for the turbulent intensity profiles in the near wall region and further downstream the stagnation point. It means that, although achivements have been gained by RNG k ε model in the prediction of some turbulent flows, modifications should be performed to the model for accurately simulating the slot impinging jet flow.