路口     

徐亚坤 《希望月报(上半月)》2006,(4)

前方出现了两个路口,我面对眼前的路口极其无奈,蓦然回首,回顾曾经走过的无数路口,脑中犹如一团乱麻,毫无头绪。又要做出一个选择,我有点不耐烦了,人生的路上为什么要有那么多的路口?为什么不能有一条直通目的地的大路呢?太多的路口,太多的  相似文献   

Features of flow past square cylinder with a perforated plate     

汪健生  徐亚坤  程浩杰 《天津大学学报(英文版)》2016,22(6):544-554

A numerical investigation was performed on the reduction of the fluid forces acting on the square cylinder in the laminar flow regime with a perforated plate. The effects of geometric parameters such as the distance between the square cylinder and the perforated plate on the wake of the square cylinder were discussed. Furthermore, the flow characteristics such as the drag coefficient, lift coefficient, Strouhal number and flow pattern were obtained. It can be concluded that the drag force of the square cylinder reduces to some extent due to the addition of the perforated plate. The flow structure varies when the perforated plate is located behind the square cylinder. Moreover, the recirculation zone augments with the increase of L/D, and the vortex trace on the upper and lower surface of the square cylinder moves gradually backwards until a stable recirculation zone formed between the square cylinder and the perforated plate.  相似文献