Liquid metal MHD effect and heat transfer research in a rectangular duct with micro-channels under a magnetic field

Abstract

The liquid metal blanket of a fusion reactor acts the role of tritium multiplication and energy transportation in a strong magnetic field environment. Liquid metal in fusion blanket is different from traditional flow and heat transfer due to magneto hydrodynamics (MHD) effects. A numerical simulation is employed to investigate the convection heat transfer between liquid metal and micro-channels heated surface under an external magnetic field. It can be found that under the influence of magnetic field, liquid metal can produce strong jet near the wall which drives the liquid metal flow together inside the channel. The MHD Hunt flow effect is intensified with the enhancement of the magnetic field and the results indicate that the magnetic field is beneficial to the energy transport and conversion of liquid metal blanket due to the jet flow on the wall that caused by the magnetic field. From the point of view of enhanced heat transfer, 32% of the heat transfer enhancement under the influence of strong magnetic field provides a new way to solve the heat transfer with high heat flux density. The expression is fitted between Nu number with Re number, the magnetic interaction number and flow distance, which can be used to predict the change of heat transfer intensity between the liquid metal and the micro-channels heated plate with the magnetic field intensity.