Electrode Geometry Optimization in Vortex-Type Seawater Magnetohydrodynamic Generators

TL;DR

This paper explores how different electrode geometries affect the efficiency and power output of vortex-type seawater MHD generators, demonstrating that optimized designs can significantly enhance performance.

Contribution

It introduces a comparative analysis of three electrode geometries using combined analytical and numerical methods, highlighting the impact on generator efficiency.

Findings

Whole-area electrode increases power output by 155%

Spiral electrode reduces internal resistance but lowers open-circuit voltage

Simulation results closely match theoretical models with less than 4% deviation

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.