Compressibility Effects on Boundary Layer Receptivity and Dielectric Barrier Discharge Plasma Actuation

Speaker: Marie Denison, Texas Instruments
April 29, 2014

Presentation

Abstract

A detailed understanding of receptivity in compressible flows is essential to devise efficient boundary layer stability control strategies for high-speed aerodynamics and inlets. To date, little work as been devoted to the analysis of how flow regime and geometry dependent receptivity information can be used to maximize flow control authority. The present work takes steps in this direction, through a two-dimensional analysis of the receptivity of supersonic flows over a flat plate. Dielectric Barrier Discharge (DBD) plasma actuators are selected as perturbation sources, in relation with their potential application as dynamic synthetic roughness.

The reported analysis is centered on fluid-plasma interactions in regimes where the boundary layer is laminar and unstable. The velocity induced by DBD discharges is typically under 10m/s, thus much smaller than the freestream velocity in high-speed flows. Therefore, the fluid-plasma interaction that supports the formation of Tollmien-Schlichting (TS) waves is governed by linear dynamics. A computational approach based on the numerical quadrature of the direct and adjoint modes of the linearized Navier-Stokes equations is used to determine the receptivity coefficients. The source term is governed by the coupling of fluid, chemistry and electric fields. In this case, the interaction is non-linear, thus the source field is obtained via a new plasma-compressible flow solver utilizing a time-marching procedure. It integrates numerically the governing equations using a finite volume, adaptive mesh refinement approach based on the Chombo C++ framework. The methodology, compressibility-specific features of the modes, simulation convergence and effects of the flow on plasma forcing will be discussed in details in the first part of the presentation. The actual receptivity analysis is carried out using the Fourier components of the simulated force field overlapping with the TS wave spectrum. The observed frequency, length scale and flow regime dependences reveal interesting features. Their analysis and significance in terms of optimum receptivity and design of experiments will be the subject of the second part. The talk will conclude with some projections on research needs related to synthetic roughness applied to 3D systems such as swept wings or supersonic cones, that offers promising prospects for real time control and adaptability to flight conditions.

Biography

Marie Denison received an M.S. degree in Aerospace Engineering from the University of Texas at Arlington, TX (2013), Ph.D. in Electrical Engineering from the University of Bremen, Germany (2005) and M.S. in Applied Physics from the University of Liege, Belgium (1998). From 1998 to 2005, she worked at Infineon Technologies, Munich, Germany on the development of semiconductor power devices and modeling of their reliability. In 2005, she joined Texas Instruments, Dallas, TX, where she designed and developed TI’s first 700V power transistors and participated to the launch of a new MEMS platform. Throughout her career, Marie conducted multiple research programs in the areas of solid-states device, packaging, material and system modeling, resulting in 14 Journal and 29 international conference publications. Her current research is focused on computational physics, CFD and high-speed flow control for aerospace applications.