The reduction of drag on a blunt body is a topic of considerable interest. Understanding drag reduction on a cylinder provides a fundamental understanding of the drag reduction on general blunt bodies. Herein, a microfiber coating with a hair-like structure is examined as a passive drag reduction coating on a cylinder. The drag reduction performance of the microfiber coating is studied in both symmetric and asymmetric configurations under the subcritical flow regime It is found that the symmetrically coated cylinder shows twice the drag reduction as that in the asymmetric case. It is shown that the angular position of the microfiber coating has a considerable impact on the performance of the coating and determines whether there is an increase or decrease in drag. This trend is consistent for both the asymmetric and symmetric configurations. It is also found that the flow features downstream of the cylinder are impacted by the configuration of the coating. The dominant frequency of the symmetric configuration in the rear flow of the cylinder is higher than that of the asymmetric configuration. The location of the dominant frequency is also further downstream for the symmetric configuration as compared to the asymmetric configuration.

减少钝器上的阻力是一个令人关注的话题。了解圆柱体上的减阻提供了对一般钝体上的减阻的基本了解。在本文中，具有毛发状结构的微纤维涂层被检查为圆柱体上的被动减阻涂层。在亚临界流态下，研究了对称和不对称结构下微纤维涂层的减阻性能。发现对称涂层的圆柱体的减阻能力是不对称情况下的两倍。结果表明，微纤维涂层的角位置对涂层的性能有相当大的影响，并决定了阻力的增加还是减小。这种趋势对于非对称和对称配置都是一致的。还发现，圆柱体下游的流动特征受到涂层构造的影响。在汽缸的后流中，对称构型的主导频率高于非对称构型的主导频率。与非对称配置相比，对称配置的主频位置也位于更下游。