Heat Exchange Enhancement by Extremum Seeking Boundary Feedback Control in 3D Magnetohydrodynamic Channel Flow
L. Luo and E. Schuster
49th IEEE Conference on Decision and Control
Atlanta, Georgia, December 15-17, 2010
Abstract
|
|
Electrically conducting fluids are generally favored as heat transfer
media for their excellent heat conduction and high boiling point.
However, the movement of such fluids under the presence of imposed
transverse magnetic fields can generate substantial
magnetohydrodynamics (MHD) effects including the need of higher
pressure gradients to drive the fluids and lower heat transfer rates
due to the laminarization of the flows. In this work we propose an
active boundary control to overcome some of these unfavorable MHD
effects inside a 3D MHD channel flow. Extremum seeking is used to
adaptively tune a fixed-structure boundary controller to maximize in r
eal time a cost function related to heat transfer. The closed-loop
controller achieves the ultimate goal of increasing overall heat
transfer rate through the channel walls, and therefore enhances the
efficiency of the heat exchanger. The velocity dynamics is predicted
by a pseudo-spectral solver while the temperature dynamics is
predicted by a finite difference solver. Simulation results show the
efficiency of the proposed controller.