亚临界雷诺数下粗糙圆柱绕流数值模拟研究

Based on standard k-ε, the two-dimensional flow around a circular cylinder with different surface roughness is numerically simulated at a subcritical Reynolds number of 3 900. The effects of surface roughness on the lift coefficient, drag coefficient, vorticity field and surface pressure distribution are analyzed. The results show that with the increase of surface roughness, the number of peak frequencies of drag coefficient fluctuation decreases, the dominant frequencies of lift and drag coefficient changes irregularly, and the average drag coefficient and root-mean-squared lift coefficient decrease. The regularity of wake vortex arrangement and the strength of vortex shedding decreases. The flow separation point moves towards the rear of the cylinder as the roughness increases. At the back of the cylinder, lower pressure coefficients correspond to higher roughness. The results of this paper are helpful to the research of cylindrical flow control technology.