A preconditioned Krylov method for solution of the multi-dimensional, two fluid hydrodynamics equations

A preconditioned Krylov method is introduced for reducing the computational burden in the solution of the multi-dimensional, two fluid hydrodynamics equations. The BILU3D preconditioned BICGSTAB method was applied to the linearized continuity equation in the inner iteration of the fully implicit solution of the mass, energy, and momentum equations in the EPRI code VIPRE-02. A nuclear reactor thermal-hydraulics test problem was performed with 104 multi-dimensional flow channels in the vessel. For the simulation of a typical pressurized water Reactor steam line break transient, the overall execution time was reduced by more than 50% compared to the existing solution techniques which utilize stationary alternate direction implicit (ADI) iterative methods for the inner iteration.