Electromagnetic (EM) pumps, which drive liquid metal by electromagnetic force in Fast Reactors, have been developed  . Annular Linear Induction Pump (ALIP) is one of EM pumps. There have been some reports in which developed pressure’s drop and fluctuation were described near the top of the relation curve between developed pressure and flow rate (P-Q curve). These phenomena were reported by Gailitis, Kirillov and Araseki. Araseki simulated this phenomenon by two-dimensional (2D) code and reported that it is characterized by vortexes, which were initiated by azimuthal non-uniformity of sodium flow velocity and/or magnetic field, in the sodium flow.
We calculated the developed pressure of an EM pump by 2D magnetohydrodynamics (MHD) code and designed the EM pump. The code simulated the developed pressure with high accuracy in normal operations. When the flow rate was lower than the one at the top of P-Q curve, the developed pressure’s drop and fluctuation occurred. The fluctuation could disturb the stable operation of the pump. For fear of this phenomenon, the design of EM pump is sometimes too conservative. To simulate this phenomenon and examine its occurring conditions, we have developed a new three-dimensional (3D) MHD code. Clarification of these conditions for the occurrence of this phenomenon will enable to design a new structure or determine its operation conditions reasonably.
This paper describes the simulation results focusing on the occurrence of developed pressure’s drop and fluctuation. We use initial conditions which have azimuthal non-uniformity of sodium velocity to simulate the initiation of vortexes in sodium. The 3D MHD code simulates the developed pressure’s drop and fluctuation by vortexes and provides more clear illustration of their occurrence.