By-pass transition control with a DBD plasma actuator model coupled with a laminar kinetic energy turbulence model

Abstract

The effect of a DBD plasma actuator on the by-pass boundary layer transition control is numerically investigated. A two-equation DBD plasma actuator model is coupled with a three-equation eddy-viscosity turbulence model, which adopts the laminar kinetic energy concept. The investigated test-cases concern zero and variable freestream pressure gradient transitional flows on a flat plate with a sharp leading edge, which belong to the ERCOFTAC experimental database. The experimental data describe the transition characteristics with no plasma actuation and hence, they are used to assess the turbulence model behaviour and as a reference point in order to quantify the coupling effect of the plasma actuator model with the laminar kinetic energy concept. The investigation is focused on the effect of the varying plasma actuator voltage on transitional and turbulent boundary layer characteristics, such as the Reynolds-stresses, the turbulent dissipation and the laminar kinetic energy distributions. The results show that with the DBD actuator activated, the turbulent quantities are suppressed, the transition onset location moves downstream and a boundary layer transition delay is observed.