抄録
In order to develop a new mixing procedure, we conduct DNS (direct numerical simulation) of vector control for free jet. A nozzle is rotating around the streamwise axis of jet. From view of instantaneous vortex structures, it is found that the structures are modulate, compared with the case of the free jet. In contours of ensemble averaged streamwise velocity, the jet diffuses largely in the radial direction. In addition, in order to estimate the mixing performance, the statistical entropy is calculated. It is found that the mixing efficiency are improved than that of uncontrolled case. Further for a candidate case of vector control, a structural mode analysis is conducted with both POD(proper orthogonal decomposition) and DMD(dynamic mode decomposition). It reveals that a dominant mode structure which is governed with the rotating frequency of vector control, seems to contribute to the mixing enhancement downstream.
