气固两相流体绕圆柱流动的数值模拟  

Numerical Simulation of Gas-particle Two-phase Flows Passing Circular Cylinder

作　　者：黄远东[1] 阎满存[1] 张红武[1] 王光谦[1] 吴文权[2] 

机构地区：[1]清华大学土木水利学院,北京100084 [2]上海理工大学,上海200093

出　　处：《中国沙漠》2001年第2期200-203,共4页Journal of Desert Research

基　　金：国家自然科学基金项目(59890200)

摘　　要：基于离散涡方法（ＤＶＭ）求得的非定常不稳定流场和颗粒的Ｌａｇｒａｎｇｅ运动方程，数值模拟了高雷诺数下的气固两相圆柱绕流，结果证明了气固两相流动中颗粒运动与流体旋涡存在着明确的相关结构：①气体流经圆柱体时产生不稳定的剧烈分离流动，在圆柱绕流尾迹区内存在着复杂的旋涡发展演化过程，由于旋涡对其周围颗粒的诱导作用，使得在足迹区内中等尺度（Ｓｔ～Ｏ（１))的颗粒从均匀气固混合物中分离出来而往旋涡区运动，并最终在旋涡结构的外沿聚集。③Ｓｔ》１的颗粒几乎不受旋涡的影响，其运动主要由本身初速度和惯性决定；而Ｓｔ《１的颗粒沿流线运动，它们不与圆柱体发生碰撞。We present a numerical investigation on the two-dimensional, dilute gas-particle two-phase flows passing a circular cylinder at high Reynoldes number. Here we apply the Discrete Vortex Method (DVM) to compute the unsteady and unstable gas flows, and adopt a Lagrangian approach to simulate the particle motion in flows. We numerically demonstrate that the definite interrelated structure exists between the particle motion and the vortices in gas-particle two-phase flows: Very large size particles (St》1) are less affected by the vortices, of which motion is mainly determined by the initial velocity, thus follow nearly straightline trajectories. However, very small size particles (St《l) follow the streamlines, have not impact with the blunts. (2) The motion of intermediate size particles (St^O (1.0), such as St＝0.3) is obviously influenced by the vortices. When gas passes a circular cylinder at high Reynoldes number, unstable flow with massive separation is formed, the complicated motion of vortices exists in the wake region. Intermediate size particles are separated from the gas-particle mixture, then move toward the wake vortex region, finally concentrate near the outer edges of the vortex structures.

关 键 词：气固两相流动 旋涡 颗粒运动 相关结构 数值模拟 雷诺数 

分 类 号：O359[理学—流体力学]