Experimental and Simulation Study on Electroconvective Silicone Flows Produced by a Surface Dielectric Barrier Injection Actuator Subjected to an AC Signal

Silicone oils acting as alternatives to mineral oils have received increased attention in electrical installations cooling fields, and thus electroconvective silicone flows induced by a surface dielectric barrier injection (SDBI) actuator is worth studying. The flow behavior is recorded through the Particle Image Velocimetry (PIV) method and a polarity-dependent flow direction is obtained by using phase analysis of velocity data. In an attempt to explain this unusual phenomenon, an EHD wall jet model considering electrochemical injection and adsorption mechanism of electrical double layer (EDL) at dielectric solid/liquid interface as well as charge accumulation effect is built based on the finite element method. The time-averaged velocity field of each phase in experiment is consistent with that observed in simulation. With the aid of simulation, coupling characteristics of flow convection and charge motion are obtained, which is usually hard to capture in experiment.