01. Experimental/Computational Fluid Dynamics

We are currently exploring the flow around columnar objects in uniform flow. In particular, we are interested in studying the potential of DBD plasma actuators (PA), which induce localized flow by dielectric barrier discharges in the context of controlling the flow around a square cylinder. We have thus far observed that by placing PAs at the front corner of a cylinder where the flow separates and by driving the PA in bursts mode (periodic on-off driving), the newly formed vortices, which we have termed "burst vortices," appear to suppress the Kalman vortex shedding and reduce the fluid force acting on the cylinder. We also found that this reduction of fluid force is more effective when the burst drive frequency is at a certain value. Based on these results, we conducted and discussed the following studies, which were based on the results of numerical simulations using commercially available thermo-fluid analysis software. In order to simulate PAs, we pseudo-simulated them through volumetric force addition. We sought to verify the relationship between the change in the burst vortices as a function of burst frequency and the suppression of Karman vortex shedding, as well as the reduction of fluid force. Additionally, we explored the mechanisms underlying the reduction in fluid force and investigated the potential reasons for the observed optimal frequency range.