LATTICE BOLTZMANN SIMULATION OF MAGNETHYDRODYNAMICS NATURAL CONVECTION FLOW FOR SALT WATER IN A HORIZONTAL CYLINDRICAL ANNULUS

Abstract

Natural convection of an electrically conducting fluid under the different directions ofmagnetic field in a horizontal cylindrical annulus is numerically studied using lattice Boltzmannmethod (LBM). The inner and outer cylinders are maintained at uniform temperatures. Detailednumerical results of heat transfer rate, temperature and velocity fields have been presented for saltwater with Pr=13.2, Ra=105 to 106 and Ha=0 to 100 for three directions of magnetic field. Thecomputational results reveal that in horizontal cylindrical annulus the flow and heat transfer aresuppressed more effectively by direction and intensity of magnetic field. It is also found that theflow oscillations can be suppressed effectively by imposing an external horizontal magnetic field.The average Nusselt number increases with rise in radius ratio but decreases with the Hartmannnumber. Furthermore, it can be observed that there is a good agreement between the present resultand those predicted by available benchmark solutions under the limiting conditions.