Abstract
In order to develop a new mixing procedure, we conduct DNS (direct numerical simulation) of dynamic control for free jet. The inflow velocity of jet is unidirectionally or alternately rotated around streamwise direction. From view of instantaneous vortex structures, it is found that the structures are markedly modulated, compared with the case of the free jet. In addition, in order to estimate the mixing performance, the statistical entropy is calculated. It is found that the mixing efficiency are improved with the alternate rotation than that of the unidirectional rotation case.