Tian Xinliang’s group proposed a novel flow control method called "Flexible coating reduces drag" (FCRD) with a flexible enclosure constructed behind the bluff body to adjust the fluid forces received and the flow pattern around it. Compared with the traditional flow control methods, FCRD does not change the structure of the control object and thus has a positive engineering application prospect. Besides, FCRD brings out a new "fluid-structure-fluid" interaction problem, which needs further investigation.