针对壁面旋转变径管内螺旋流的压力应变项研究

Research on Pressure Strain Correlation Terms in the Reynolds Stress Model for Spiral Flow in Reducing Pipes With Rotating Wall

通过壁面旋转变径圆管内螺旋湍流流动特征的分析,确定其切向速度场内涡流区为微团旋转主导的椭圆形流动,外涡流区为微团变形主导且受壁面旋转影响的双曲形流动.进而利用张量的不变量理论,引入旋转率张量与应变率张量的综合不变量作为模型系数,将适用于微团旋转主导的旋转湍流Reynolds应力压力应变项修正模型拓展到了非旋转效应主导的双曲形流动中.将修正压力应变项应用于壁面旋转变径圆管流场的模拟,并将结果与实测结果进行了对比,验证了修正模型的改进效果.

The characteristics of flow field in reducing pipes were analyzed. It was determined that the inner vortex in the tangential velocity field is an elliptic flow dominated by the rotation of fluid micelle. The outer vortex is a hyperbolic flow dominated by deformation of fluid micelle and influenced by wall rotation. With the tensor invariant theory, an invariant integrating the rotation rate tensor and the strain rate tensor was introduced as the model coefficient. Then the modified model for pressure and strain terms in the Reynolds stress, which is applicable to flow dominated by rotation, was extended to hyperbolic flow. Ultimately, the model was applied to the flow field simulation of the reducing pipe with rotating wall. Comparison between numerical results and measured ones proves the effectiveness of the modified model.