Department of Marine Technology, Amirkabir University of Technology, Tehran, Iran
The use of magnetohydrodynamic (MHD) blanket propulsion system in ships, even with low efficiencies, has particular benefits that can make them an appropriate option for the marine designers. Accordingly, any attempt to increase the efficiency of these systems requires full recognition of their performance in different conditions. In the present study, as a continuation of previous numerical works by the current authors, a magneto-hydrodynamic blanket propulsion system has been built and experimentally studied through examining the MHD forces produced in different voltages. Copper and gold have been used and compared as electrodes and the high advantage of gold has been demonstrated. The effect of electrolysis on the behavior of the blanket is analyzed. It has been demonstrated that although electrolysis restricts high currents in lower voltages (lower than ~140V) and the saturation of hydrogen decreases the MHD forces due to low electrical current (~140V up to ~160V), the saturation of hydrogen around cathode at high voltages (more than ~160V), makes a dielectric barrier which soon breaks down and make the production of plasma possible, which in turn highly increases the thrust force of the MHD blanket. Therefore, three regimes have been introduced and described for the MHD blanket; the electrolysis regime, the transition regime, and the hot plasma regime. Based on the obtained results, one may conclude that the present results have offered good evidence about the possibility of increasing the MHD blanket performance through plasma production in water.