Skin-friction drag reduction in a channel flow with streamwise-aligned plasma actuators

Abstract

Direct Numerical Simulations in a turbulent channel flow at a moderate Reynolds number are performed in order to investigate the potential of Dielectric Barrier Discharge (DBD) plasma actuators for the reduction of the skin-friction drag. The idea is to use a sparse array of streamwise-aligned plasma actuators to produce near-wall spanwise-orientated jets in order to destroy the events which transport high-speed fluid towards the wall. It is shown that it is possible to reduce the drag by about 33.5% when the streamwise-aligned actuators are configured to generate appropriate spanwise-orientated jets very close to the wall so that the sweeps which are mainly responsible for the skin-friction are destroyed. We demonstrate that it is possible to achieve significant drag reduction with a sparse array of streamwise-aligned plasma actuators, with one order of magnitude less actuators than previous experiments in a similar set-up

Flat plate drag reduction using plasma-generated streamwise vortices

“…Thus, the production is mostly confined to the near-wall region, accounting for an increased production for y/δ < 0.012 (y + < 7) but a reduced production further away for y/δ = 0.012-0.109 (y + = 7-60). A similar observation was also made from the DNS results of Mahfoze & Laizet (2017), who superimposed plasma-induced spanwise flow oscillation near the wall in a turbulent channel flow of relatively low Re τ ( = 180). They achieved a DR of 24 % under the optimal control parameters.…”

Dielectric Barrier Discharge Microplasma Actuator for Flow Control

“…Numerical simulations of the plasma actuator are carried out using the plasma fluid model and particle in cell model [36][37][38][39]. A simplified phenomenological model which does not model the species transport equations but can replicate the effects of the actuator in the air is the Suzen-Huang model [40]. Results close to the experimental data were obtained by various researchers who developed numerical simulations based on this model.…”

“…Results close to the experimental data were obtained by various researchers who developed numerical simulations based on this model. It is less computationally expensive than solving the species transport equations [40,41].…”

Bypass transition in a boundary layer flow induced by plasma actuators

“…The numerical simulation of DBD plasma actuators has been extensively studied, as it allows detailed examination of the induced flow. In these works, the model of DBD plasma actuators can be divided into two groups: simplified phenomenological models and first-principles-based models (Mahfoze & Laizet 2017). Simplified models assume that the response of fluid flow and the formation of plasma are decoupled due to large differences in the characteristic velocities associated with each process (Mertz & Corke 2011).…”