Electrode Geometry Optimization in Vortex-Type Seawater Magnetohydrodynamic Generators

Abstract: Magnetohydrodynamics (MHD) generators present a promising pathway for clean energy conversion by directly transforming conductive fluids' kinetic energy into electricity. This study investigates the impact of electrode geometry modifications on the performance of a vortex-type seawater MHD generator. Three electrode designs, partial, whole-area, and spiral, are analyzed through combined analytical and numerical simulations using COMSOL Multiphysics. The study focuses on internal resistance reduction, current density distribution, and overall power output. The results indicate that electrode area and spacing are critical determinants of performance. The whole-area electrode achieves the highest output, with a 155 percent increase in power compared to the baseline partial electrode. The spiral electrode demonstrates reduced internal resistance and improved current flow but exhibits lower open-circuit voltage due to reduced electrode spacing. The simulations show strong agreement with theoretical models, with deviations of less than 4 percent in open-circuit voltage predictions. These findings highlight the importance of geometric optimization for advancing seawater-based MHD generators as sustainable and efficient energy conversion systems.