圆柱绕流湍流尾迹的分离涡模拟

Detached Eddy Simulation of Turbulent Wake around a Cylinder

摘要: 针对流体在不同雷诺数条件下流经单圆柱后生成不同的尾迹现象，本文提出基于SST方程的DES模型算法分析圆柱绕流的湍流尾迹规律。基于计算流体力学软件Fluent，绘制出尾涡的流线图和涡量图，计算升力系数、阻力系数和斯特劳哈尔数等，分析尾涡的生成、发展和脱落与雷诺数之间的关系。在低雷诺数条件下，圆柱绕流生成的尾涡具有较强的周期性和对称性，属于层流特征。随着雷诺数的增大，尾涡的规律性减弱，随机性增强，逐渐显化出湍流特征。

Abstract: Aiming at the phenomenon that the fluid flows through a single cylinder under different Reynolds numbers and produces different wakes, this paper proposes a DES model algorithm based on the SST equation to analyze the turbulent wake law of the flow around a cylinder. Based on the compu-tational fluid dynamics software Fluent, the streamline diagram and vorticity diagram of the wake vortex are drawn, the lift coefficient, drag coefficient, and Strouhal number are calculated, and the relationship between the generation, development, and shedding of wake vortex and Reynolds number is analyzed. Under the condition of low Reynolds number, the wake vortex generated by the flow around a cylinder has strong periodicity and symmetry, which belongs to laminar flow characteristics. With the increase of Reynolds number, the regularity of the wake vortex is weak-ened, the randomness is enhanced, and the turbulent characteristics are gradually manifested.