Large-eddy simulation of plasma-based wake control over a D-shaped bluff body

A numerical study based on large-eddy simulations is conducted to assess the effectiveness of plasma actuation in controlling the flow around a D-shaped bluff body at Re = 38000. Different actuator architectures are examined, placed both in the spanwise and streamwise directions, and operating in either a "steady" (constant force exerted) or "pulsed" (time-modulated force applied) modality. Both actuator configurations proved effective, with the "pulsed" modality generally providing improved performance, particularly for the spanwise configuration. The streamwise architecture yielded the largest benefits, with reductions in the mean drag coefficient and lift fluctuations up to ~6.7% and ~22.3%, respectively, compared to the ~3.3% and ~12.3% of the spanwise actuation. Additionally, a reduction in the peak value of the turbulent kinetic energy was measured in the near wake, yielding improvements of ~8.8% and ~15.4% for the spanwise and streamwise configurations, respectively. Overall, the results highlighted the potential of plasma actuation as a wake control mechanism in rounded-leading-edge bluff bodies characterized by weak forebody separation.