On the flow around a vibrating cantilever pair with different phase angles

Abstract

The unsteady flow fields generated by cantilevers were simulated using a commercial flow solver. The motion of cantilevers was described realistically with a user-define-function in the flow solver, and it was matched well with the experimentally measured one. For validation, the flow induced by a single vibrating cantilever was compared with the experimental data qualitatively, and the numerical results clearly showed that the numerical method can generate realistic flow phenomena. In the pair-wise configuration, the effect of phase angle difference between two cantilevers was analyzed by using the unsteady flow and the time-averaged velocity field. The flow was significantly affected by the phase angle difference, thus it was symmetric to the center in some cases but asymmetric in others. It was found that the interaction of counter-rotating vortices generated by each cantilever changes significantly with the phase angle difference, and this phase difference is the main factor that determines overall flow features. From the viewpoint of cooling effectiveness, the cantilever pair vibrating in counter-phase is a much more effective way to generate the airflow than the other tested cases.