有限长圆管内刚体旋转流的直接数值模拟  

Numerical Study of Dynamics of Solid-body Rotation Flow in Finite-length Pipe

作　　者：冯春娟[1] 苏进[2] 刘锋[1,3] 汪师晓 

机构地区：[1]西北工业大学航空学院,陕西西安710072 [2]西安工程大学理学院,陕西西安710048 [3]加州大学尔湾分校机械与宇航工程系,美国ca926173975 [4]奥克兰大学数学系

出　　处：《航空计算技术》2017年第3期13-17,共5页Aeronautical Computing Technique

基　　金：国家自然科学基金项目资助(11601411);陕西省教育厅科研计划项目资助(15JK1313)

摘　　要：通过对三维不可压缩粘性流体的直接数值模拟,研究了有限长圆管内刚体旋转流在初始扰动下,扰动的增长和动力学演化过程。首先,通过改变流动的Reynolds数和旋转角速度ω,分析了轴对称流动中Reynolds数和ω对流动失稳的影响。对于高Reynolds数轴对称流动,利用数值模拟得到的不稳定结果与无粘线性稳定性理论预测的结果一致。最后,为进一步研究流动不稳定发展的三维效应,又进行了完全三维流动的模拟。数值结果表明,三维流动中不稳定的主导模态为螺旋模态,模态在线性段指数增长,导致流动产生螺旋型的漩涡破裂,之后经过非线性段的增长后达到饱和,流动最终发展为轴对称泡型旋涡破裂的稳定状态。Three- dimensional direct numerical simulations of a base solid- body rotation flow with a uni- form axial velocity in a rotating, finite- length, straight circular pipe are presented. First, the axisymmetric flow are simulated to investigate the effect of Re number and swirl ratios on the dynamics of flow. We find that the instability result of high- Re axisymmetric viscous swirling flow agrees well with the prediction of the inviscid linear stability theory. Then,it is found that there exists a dominant spiral type of an instabili- ty mode when the full three- dimensional flow are simulated. This three- dimensional mode leads to a spi- ral type of flow roll-up that subsequently stabilizes on a steady axisymmetric bubble type of vortex breakdown.

关 键 词：刚体旋转流 流动稳定性 漩涡破裂 

分 类 号：O357.1[理学—流体力学]