Laminar Boundary Layer Response to a Step Input by an Array of Plasma Actuators

Bypass transition, which is a subcritical transition pathway that a boundary layer may follow from laminar to turbulent state, is caused by the growth of streaks of low and high velocity in the laminar boundary. Plasma actuators have shown promising results for controlling the growth of these streaks and prolonging the laminar state. A spanwise array of plasma actuators in a Blasius boundary layer are simulated numerically. The output of the plasma actuators is modeled as a momentum source to the flow. The momentum source is tuned to match with a particular experimental model. To address the non-minimum phase behavior of the flow when a step input is applied to the actuators, the transient vortex evolution in the far-field downstream and also directly over the region where the plasma actuators input a body force is studied. In addition, the transient evolution of the spanwise and streamwise wall shear stress components considered.