Finite Element Analysis of Magnetohydrodynamic Propulsion and the Effect of ‎End Electric Current on the Efficiency

In this paper, a marine magnetohydrodynamic thruster is simulated three dimensionally and its operating parameters are obtained. In this simulation, both electromagnetic and fluid flow fields are considered in three dimensions and the effects of magnetic field non uniformity on the operating parameters of the thruster are investigated. To do this, a typical saddle shaped MHD thruster with specific dimensions is selected and its geometry is implemented in the software environment. The electric current of superconducting coils is selected using a trial-and error method, in such a way that the average magnetic flux density in the channel becomes 15 T. An analytical model is used to validate the numerical results. It is shown that some of the operating parameters of MHD thruster, such as fluid velocity, are not affected by the end current of the channel. These parameters are functions of the effective electric current of the thruster and can be calculated analytically. On the contrary, other parameters, such as efficiency, are strongly influenced by the end effects of the channel. These operating parameters are functions of the overall electric current of the thruster and should be calculated numerically.