Separated-Flow Control Simulation with a Periodic Excitation by SDBD Plasma Actuator at Re=O(205)

Abstract

This work presents a boundary layer separated-flow control technique with a periodic excitation by an single dielectric-barrier discharge (SDBD) plasma actuator applied to an airfoil section at Re=O(205). The technique uses the Reynolds-averaged Navier–Stokes method to study the induced flow control through a body force source modeled by an SDBD plasma actuator, which is implemented in an OpenFOAM platform for free instability flow simulation. To simulate the coupling of plasma-fluid physics of a SDBD, the Kloker plasma-fluid model was used in conjunction with the k−ωSST turbulence model. Several numerical setups of OpenFOAM were tested, stable solutions were achieved with the pimpleFoam solver, second-order accurate discretization schemes a linear solver GAMG for the symmetric matrix p, and a smoothSolver with a GaussSeidel smoother for the asymmetric matrices U, k, omega, and nuTilda. The flow solver determines the pressure, velocity, and stall point including the detachment of the boundary layer for different angle attacks of the airfoil section. The resulting periodic excitation causes an efficient transversal redistribution of the main flow momentum into the boundary layer motivating the further flow reattachment to the airfoil section. The burst frequency of 3 Hz with a Cμ=1.44×10−3 and a BR=0.5 achieves a smooth and continuous increase Cl behavior, and the frequency variations do not have a noticeable impact over the Cd, extending the airfoil section stall beyond 16°.