低雷诺数下冷圆柱绕流的数值研究OA

This article utilizes three-dimensional numerical simulations on the flow around a cold cylinder with a constant Reynolds number(Re=80)and a Richardson number(Ri)ranging from-5 to-0.5,to investigate the formation mechanism of the wake structure and the influence of buoyancy on the wake structure.The results indicate that within the range of-2.5≤Ri≤-0.5,the wake structure around the cold cylinder exhibits a consistent cyclic pattern due to the influence of buoyancy.As Ri reaches a certain threshold(e.g.,Ri=-5),the cyclic pattern of the cold cylinder flow undergoes a change.With the decrease of Ri,the overall wake structure of the cold cylinder deflects in the direction of gravity,while the number of rib structures exhibits a non-monotonic variation,and the wall-attached flow of the cylinder wake intensifies.When Ri decreases to a certain threshold,flow separation occurs solely from beneath the cylinder.The lift and drag coefficients,along with the Nusselt number on the cylinder's surface,increase monotonically as Ri decreases.