Drag reduction of square cylinders with cut-corners at the front edges
Drag reduction of square cylinders with cut-corners at the front edges
复制标题
前缘切角方形圆柱体的减阻
DOI：
10.1007/s00348-014-1745-1
复制
发表时间：
2014-06-01
影响因子：
2.4
通讯作者：
Wang, Jin Jun
中科院分区：
文献类型：
--
作者：
He, Guo Sheng;Li, Nian;Wang, Jin Jun
Flow around square cylinders with cut-corners at the front edges is investigated using particle image velocimetry. It is found that drag reduction can be achieved for the tested cut-corner dimensions. The mechanism for the drag reduction is explored on the statistical and structural aspects of the flow. After cutting the corners, the fluctuation intensity of the wake is weakened, the length of the recirculation region behind the square cylinder is increased, while the width of the wake decreases. It is found that the drag coefficient is proportional to the minimum wake width, and the Strouhal number St is inversely proportional to the minimum wake width. It is revealed that the reduced wake width is due to the suppressed separation over the side surfaces for the cylinders with cut-corners at the front edges. On the structural aspect, the phase-averaged flow field and the modes from proper orthogonal decomposition both indicate a decrease in the wake vortex size. A statistical analysis of instantaneous vortices based on Oseen vortex fit reveals that not only the size of the vortex is reduced, but also the strength is weakened.
