圆柱亚临界-临界-超临界流动特性的大涡亚格子模型比较研究  

COMPARATIVE STUDY OF SUBGRID LARGE EDDY MODELS ON FLOW PREDICTION OF CIRCULAR CYLINDER IN SUBCRITICAL-CRITICAL-SUPERCRITICAL REGIME

作　　者：祝志文[1] 邓燕华[1] 

机构地区：[1]湖南大学土木工程学院,长沙410082

出　　处：《动力学与控制学报》2016年第4期371-378,共8页Journal of Dynamics and Control

基　　金：国家自然科学基金资助项目(51278191);国家重点基础研究发展计划(2015CB057702;2015CB057701)~~

摘　　要：为获取圆柱在亚临界、临界和超临界区内的气动特征,基于大涡模拟并分别采用Smagorinsky亚格子尺度模型和动力亚格子尺度模型计算了Re=4.1×10^4~8.2×10^5内的绕流场.将获得的圆柱定常与非定常气动特性与相关文献进行了对比.研究表明,两种亚格子模型均能给出圆柱升力系数平均值、RMS值和涡脱St数的合理估计,能预测阻力系数的下降.但两种亚格子模型均无法准确预测临界区阻力系数的快速下降、不同Re数下压力系数平均和RMS值在圆柱表面的分布.在临界和超临界区,Smagorinsky亚格子尺度模型可能高估了亚格子湍流粘性;相反,动态亚格子模型可能在流场部分区域明显低估了亚格子湍流粘性.In order to obtain the aerodynamics of the circular cylinder in subcritical-to-supercritical flow regime,the large eddy simulations（ LES） with the smagorinsky subgrid scale and dynamic subgrid scale models are respectively employed to predict the flow field where Re is from 4. 1 × 10^4~ 8. 2 × 10^5. The obtained steady and unsteady aerodynamics are compared with available data in other references. The results show that both subgrid scale models provide reasonable estimation on mean and RMS lift coefficients,vortex shedding St number and drop of drag coefficients. However,the drag crisis in critical regime is not accurately predicted,but reasonable estimation on mean and RMS pressure distribution around the cylinder is obtained. In critical and supercritical regimes,the smagorinsky subgrid scale model may overestimate the subgrid turbulent viscosity,while the dynamic subgrid scale model may significantly underestimate the subgrid turbulent viscosity in some areas of the flow field.

关 键 词：Smagorinsky模型 动态亚格子模型 气动特性 临界区 

分 类 号：O357.5[理学—流体力学]