Electro-magnetic flow coupling for liquid metal blanket applications

Highlights: • Numerical simulations to study the effects of electrical coupling of adjacent fluid domains caused by leakage currents across common walls are performed. • Various orientations of magnetic field and driving pressure gradients are considered. • Intense multi-channel effects are present when ducts are connected at the side walls and the flow is driven in the same direction. • Calculations of 3D MHD flows in parallel bends are performed too. An example is shown for the case in which the flow is driven only in the lateral ducts. - Abstract: In the framework of the development of liquid metal blankets to be tested in ITER and for applications in a DEMOnstration reactor, magnetohydrodynamic (MHD) interactions between the electrically conducting lead lithium alloy and intense magnetic fields have been investigated numerically. In all proposed liquid metal blanket designs the presence of leakage currents that flow from one fluid domain into the adjacent one crossing electrically conducting walls has to be taken into account since it influences significantly the flow partitioning in parallel ducts. The way in which electrically coupled flows affect each other depends on orientation of common walls with respect to the magnetic field, on flow direction in adjacent channels and on the path of leakage currents. The present paper aims at providing an overview of main phenomena that occur in multiple channels where flows are coupled by an exchange of electric currents. The understanding of those basic flows is required for the study of complex 3D coupling conditions.