Progress and outlook of plasma-based turbulent skin-friction drag reduction

Aircraft friction drag accounts for more than half of the total cruising drag; thus, turbulent friction drag reduction is vital to improving flight performance and reducing flight costs. Plasma actuation is a controllable disturbance of pressure, temperature, and physical property changes caused by discharging gas or the moving plasma subjected to electromagnetic force. Compared to other turbulent friction drag reduction methods, plasma actuation has many advantages, such as lightweight and intelligent control capability, so it has received widespread attention. This paper provides a detailed overview of the development history and research progress of the plasma-based turbulent drag reduction method. In flat-plate turbulent boundary layers, plasma actuation can reduce friction drag by more than 40% by inducing large-scale vortical structures that enhance transportation. For airfoils at cruising angles of attack, plasma actuation can reduce the total drag of airfoils by up to 13.7% at a freestream velocity of 20 m/s. Developing new efficient plasma drag reduction actuation methods, adapting to flows with high Reynolds numbers and strong pressure gradients, and developing from open-loop blind control to intelligent adaptive control combining artificial intelligence, are the future development trends of the plasma-based turbulent drag reduction method.