Development of Computer Code for Analyzing Liquid Metal MHD Flow in Fusion Reactor Blankets, (I)Flow in Circular Pipe under Uniform Transverse Field

摘要

A numerical technique for solving liquid metal MHD problems has been developed as a design tool of fusion reactor blankets. Blanket cooling ducts have spatial changes in boundary conditions of flow. The changes generate recirculating currents in the fluid which affect the velocity profile. The present code can analyze the MHD problems in the ducts which have planes of symmetry perpendicular to the uniform magnetic fields. One example is a straight circular pipe with axially varying wall conductance. Under the very strong uniform field, the current etc. in the fluid are derived to be uniform in the field direction. Therefore, these values in the diametric plane perpendicular to the field well represent the fluid properties in the whole duct. Thus we can replace the three-dimensional problem with the two-dimensional one. The following calculational procedure is used in the code. With an assumed velocity distribution, the electric potential and current distributions are calculated at first using a finite difference method. The result usually does not satisfy all the governing equations. The velocity is redistributed iteratively until the solution which satisfies all the governing equations is obtained.