Reynolds数22000的孤立方柱绕流的大涡模拟  

Large-Eddy Simulation of Flow around Isolated Square Cylinder at Reynolds Number 22000

作　　者：李真子[1] 林自城 高志栋[1] 叶建[1] 

机构地区：[1]重庆大学动力工程学院,重庆400044

出　　处：《气体物理》2017年第3期17-23,共7页Physics of Gases

基　　金：国家自然科学基金(51206198);中央高校基本科研业务费(CDJZR12140030)

摘　　要：方柱绕流是典型的钝体绕流问题,蕴含了丰富的流体力学现象,对这类流动的准确预测面临着诸多挑战.采用自主发展的大涡模拟程序,对来流Mach数M=0.3,Reynolds数Re_D=22 000的绕孤立方柱流动进行了细致模拟,亚格子模型使用动力涡黏模型.对计算结果的分析表明,大涡模拟所得的平均流场及Reynolds应力分布与已有实验数据和直接数值模拟结果均吻合较好,验证了预测结果的可靠性;在此基础上对瞬态流场进行了研究,展示了计算条件下方柱绕流分离转捩及尾迹区旋涡交替脱落形成Karman涡街的全过程,为更细致的流动机理探索奠定了基础.The llow around a square cylinder is a canonical test-case of bluff body llows which includes a lot of phenomena in fluid mechanics. Nevertheless,it is still a great challenge to predict such kind of Ilows accurately. In current work an in-house large-eddy simulation （ LES） code was employed to simulate flow around an isolated square cylinder,where Mach number was 0.3 and Reynolds number was 22 000 respectively,and the subgrid-scale （SGS） model was dynamic Smagorin- sky model. Preliminary analysis of the numerical results suggests that time-averaged flow field and Reynolds stress compo-nents are in good agreement with existing experimental and direct numerical simulation （DNS） results, which indicates the reliability of the present work. Moreover, instantaneous flow field was analysed to display separation and transition process of the flow and the whole process of vortex shedding in the wake region. This work laid the foundations for more in-depth a-nalysis of relevant flow physics.

关 键 词：孤立方柱 大涡模拟 非定常分离 转捩 旋涡脱落 

分 类 号：O357.5[理学—流体力学]