Optimization of magneto-hydrodynamic control of diffuser flows using micro-genetic algorithms and least-squares finite elements

In this paper we consider the problem of multidisciplinary design and optimization (MDO) of a diffuser for a steady, incompressible magnetohydrodynamic (MHD) flow. Given a fixed diffuser shape, the optimizer should find the distribution of the wall magnets that will maximize the static pressure increase from inlet to outlet. This design problem is solved through the use of a genetic algorithm based optimization program coupled with a finite element based MHD simulation program. For MHD simulation, a least-squares finite element method (LSFEM) based program has been developed. The use of LSFEM allows the use of equal order approximation functions for all unknowns and is stable for high Reynolds numbers. Optimization was accomplished using a micro-genetic algorithm (GA) based program. The micro-GA is capable of searching the design space with a population much smaller than that required by classical GA. The optimization was performed on a parallel computer composed of commodity PC components. Results show that an applied magnetic field with the proper strength and distribution can significantly improve the static pressure rise over the case of no magnetic field. (C) 2001 Elsevier Science B.V. All rights reserved.