Numerical Study on Azimuthal Partition Combined Plasma Control for Rotor Airfoil Deep Dynamic Stall at High Advance Ratio

To address the challenge of effectively suppressing deep dynamic stall on the retreating side of rotor blades at high advance ratios, an azimuthal-zone plasma combined control strategy is proposed. This strategy is grounded in the complementary physical mechanisms of AC-DBD and NS-DBD actuators—AC-DBD delays separation onset through continuous momentum injection, while NS-DBD weakens the dynamic stall vortex via pulsed thermal perturbations—and differentially combines the two actuation modes according to the phase-dependent characteristics of dynamic stall evolution at different azimuthal angles on the retreating side, thereby achieving full-cycle, comprehensive dynamic stall suppression. In this study, the unsteady Reynolds-averaged Navier–Stokes (URANS) method, coupled with phenomenological source-term models of AC-DBD and NS-DBD, is employed to numerically investigate the dynamic stall process on the retreating side of rotor blades at high advance ratios. The results demonstrate that the proposed combined control strategy effectively exploits the temporal complementarity of AC-DBD and NS-DBD at different stages of the dynamic stall cycle: during the upstroke phase, AC-DBD provides early intervention through momentum injection; during the stall-development phase, NS-DBD actively modulates the separated shear layer and attenuates the vortex intensity through pulsed actuation; and during the reattachment phase, the two actuators work in synergy to accelerate flow recovery. Quantitative analysis shows that the synergistic control achieves a 13.8% increase in lift and a 20% reduction in lift-coefficient hysteresis-loop area, with control benefits significantly superior to those of single-actuation modes. This study provides a new theoretical basis and technical reference for active flow control of dynamic stall on high-advance-ratio rotors.