摘要
采用格子Boltzmann方法对低雷诺数下气体绕流圆柱的规律进行了研究.对比计算了双圆柱在不同圆心距、不同Re数、不同来流速度与双圆柱圆心连线角度的情况下,各个圆柱的受力大小和曳力系数.结果表明,若Re数为20,改变圆柱间距,圆柱间距在1.2d和1.4d之间时,下游圆柱所受曳力有极小值;双圆柱间距为1.6d时,双圆柱受到总曳力最小;圆柱间距大于2d时,上游颗粒受到的曳力不再受到下游颗粒的影响.若圆柱间距为1.2d,改变雷诺数,Re数在30和40之间,下游圆柱所受曳力有极小值.另外,来流速度角度对圆柱的受力影响很大.上述规律为低Re数下圆柱绕流的深入研究与应用打下基础.
Lattice Boltzmann models （LBM） is a recently developed method in computational fluid dynamics, and it is particularly suitable for flow modeling in complex boundary area. In this paper, the resistance characteristics of gas flow around two cylinders are numerically studied using LBM. The drag force and drag coefficient of each cylinder are studied by varying the cylinder distance, Reynold number, and the attack angle. Three typical scenarios are studies： The first scenario is to calculate 10 typical cases with the cylinder distance varying from 1.2d to 3.0d where the Reynolds number is fixed to be 20. The calculated results show that the smallest stress acting on the downstream cylinder exists when the cylinder distance is between 1.2d and 1.4d. Furthermore, the minimum total drag force acting on the two cylinders occurs when cylinder distance is 1.6d. We also found that the downstream cylinder has no impact on resistance coefficient of upstream cylinder when the cylinder distance is greater, than 2d. The second scenario is to study the effects of Reynolds number on the resistance characteristics of the two cylinders by fixing the cylinder distance as 1.2d. Results show that the weakest stress on the secondary cylinder in tandem arrangement exists at a point where the Reynolds number is between 30 and 40. The results in the third scenario show that the attack angle has great effect on the resistance coefficient of each cylinder. These reasonable results can server as the scientific foundation for further research and implementation of flow over multi-cylinders under low Reynold numbers.
出处
《力学学报》
EI
CSCD
北大核心
2009年第3期300-306,共7页
Chinese Journal of Theoretical and Applied Mechanics
基金
国家自然科学基金资助项目(50406025)~~
