Theor. Comput. Fluid Dyn. DOI 10.1007/s00162-013-0302-5 ORIGINAL ARTICLE Mark Riherd · Subrata Roy · S. Balachandar Local stability effects of plasma actuation on a zero pressure gradient boundary layer Received: 10 October 2012 / Accepted: 29 March 2013 © Springer-Verlag Berlin Heidelberg 2013 Abstract The effects of plasma actuation in a flat plate boundary layer with zero pressure gradient have been simulated. Based on these simulations, non-dimensional parameters and a combined wall jet/boundary layer model of the velocity profile have been developed. A parametric study using local linear stability analysis has been performed to examine the hydrodynamic stability of the velocity profiles created through this model. Convective and absolute instability mechanisms are found to be important, some of which have not been previously documented. Neutral stability curves have been computed for the different instabilities, and when put in terms of the shape factor, they still compare favorably with reported canonical results, indicating that the critical Reynolds number is primarily a function of the shape factor. These results are also discussed in relation to existing experimental results as well as with respect to their implementation. Keywords Hydrodynamic stability · Plasma actuators · Boundary layer control 1 Introduction The process of a flow’s transition to turbulence has long been a topic of study in fluid mechanics. Specifically, flows over flat plates with or without a pressure gradient are particularly important, as they share many characteristics with more complex flows. These flows can be described by the Falkner–Skan similarity solution, where the Blasius boundary layer is the special case of a zero pressure gradient (ZPG). Boundary layer flows such as these are prevalent on many types of air, ground, and marine vehicles, such as the flow over and around airfoils for fixed and rotating wing aircraft, the flat surfaces of automobiles and cargo trucks, and the sides and bottoms of ships. Reduction in the overall levels of drag on these different types of vehicles can lead to energy savings, allowing for more efficient and less costly operation, along with the associated benefits of reduced fuel consumption. Stabilization or destabilization of a boundary layer flow can have a significant impact on the level of drag experienced by the body. Stabilizing the boundary layer decelerates the laminar to turbulent transition process. When attempting to reduce the level of friction drag experienced by a body, this is a beneficial course of action, as the drag associated with a laminar boundary layer is less than the drag associated with a turbulent boundary layer. However, when aiming to reduce the drag created by flow separation downstream, it is sometimes beneficial to accelerate the laminar to turbulent transition, as a turbulent boundary layer is more likely to remain attached than a laminar boundary layer. Additional flow control applications may exist with regard to heat transfer, chemical mixing, noise control, etc. where it may be prudent to stabilize or to destabilize the boundary layer, based on the problems specifications. Communicated by O. Zikanov. M. Riherd · S. Roy (B ) · S. Balachandar Mechanical and Aerospace Engineering, University of Florida, Gainesville, FL 32611, USA E-mail: roy@ufl.edu Tel.: +352-392-9823