Lagrangian analysis of the flow induced by a dielectric barrier discharge plasma actuator array under burst mode actuation

The dynamic properties of the flow induced by a dielectric barrier discharge (DBD) plasma actuator array are investigated from the Lagrangian perspective. First, numerical simulations based on a body force model are performed to obtain the flow field induced by unsteady plasma actuation in the burst mode. The numerical simulations capture the flow characteristics of plasma actuation well. Subsequently, the ridges of the finite-time Lyapunov exponent field are employed to identify the Lagrangian coherent structures (LCSs). Both the attracting and repelling LCSs organize the plasma-induced flow’s dynamic behaviors. The attracting LCSs visualize the plasma-induced vortices. The vortex formation, development, and merging processes in the unsteady plasma actuation are resolved well by the LCSs. The material transport in the plasma-induced flow is analyzed by tracing the fluid particle motions. Then, the influences of the actuation parameters, duty cycle, and burst frequency on the flow structures are explored via the attracting LCSs. The presented results enhance the understanding of plasma actuation flow physics and promote the optimal use of DBD plasma actuator arrays.