Advances in the study of methods and mechanism\\ of

In the first section,we classify the control methods of vortex shedding in bluff bodywakes according to the control ideas that originate from thetheoretical models of vortex generation, and then brieflyintroduce the recent works of the control in china. In the secondsection, we present our work on a modified Strykowski \&Sreenivasan's method, in which the circular control element isreplaced by an element of strip or square cross-section. Theresult shows an improvement on suppression of vortex shedding froma circular cylinder and from a square cylinder at high Reynoldsnumber flow. The influence of the degree of control element'sbluffness on the suppression is investigated. In the thirdsection, the theoretical models of vortex generation are analyzedand examined by using experimental data. We conclude that themechanism of the element control is not related to the change ofseparation position or to the reduction of base suction, or to thechange of span-wise correlation of the flow, or to the preventionof interactions between the separated shear layers, but is relatedto the local modifications of the velocity profiles downstream thebluff body and the change in their instability nature. In thefinal section, we discuss the future study of the control elementmethod and the prospects for engineering applications.