Effects of double diffusion and Soret effect on MHD braking of liquid metal packed between enclosed rotating cylindrical annulus

Abstract

In this study, the combined effect of Joule heating and Soret number on magnetohydrodynamics (MHD) braking of incompressible stratified liquid metal packed between a confined rotating annulus has been investigated. Both axial sinusoidal temperature and as well as sinusoidal concentration have been imposed in this braking system. However, radial cooling is enforced on the rotating disc of the braking system. The Soret effect on concentration gradient has been observed when the stratified liquid is exposed to a temperature gradient along with an axial magnetic field at different buoyancy ratios. A significant difference in convection heat and mass flow can be seen. The average shear wood decreased from 8.97 to 2.36 and the average Nusselt number decreased from 8.6 to 2.8 between the outer rotating disk and inner stationary disks at positive buoyancy ratios. This huge difference in heat and mass convection near the inner disk with respect to the outer brake disk confirms the MHD braking effect. Moreover, comparative studies of mass convection with respect to convective heat transfer have been observed based on the average magnitude of Sherwood and Nusselt numbers at both positive and negative buoyancy ratios.