用随机涡法研究混合层中的颗粒扩散

由于 Stuart的涡街模型不能模拟大尺度旋涡的发展与合并过程 ,因而影响了其所得结论的一般性。本文应用随机涡法对混合层中大尺度旋涡的产生、发展与合并过程进行直接模拟 ,定性研究了颗粒在混合层中的扩散 ,并在更一般的意义下获得了与 Crowe相同的结论。

A NUMERICAL STUDY OF PARTICLE DISPERSION IN MIXING LAYER WITH RANDOM VORTEX METHOD

Quasi two dimensional large scale vortex structure has a dominant effect on development of plane mixing layer.Crowe used Stuart's Vortices to simulate particle dispersion in free shear flows.The results of his simulation show that the experimental observations indicating particle dispersion rates greater than the fluid dispersion rates in free shear layer could be attributed to the effect of large scale vortex structure on particle dispersion.It is the incapability of Stuart's vortices of simulating development and merging process of these large scale vortex structure,that compromises the generality of his results.In this paper,we studied the particle dispersion in the mixing layer by using the random vortex method to simulate the creation,development and merging processes and the same results as Crowe's are obtained but in a more general sense.