Effect of geometry on magneto-convection in a square enclosure filled with a low Prandtl number fluid

Abstract

Numerical simulation of magneto-convection heat transfer and fluid flow is analysed in an enclosure with a centrally located adiabatic square-shaped body using finite volume method. The enclosure's opposite walls (right and left) are heated and cooled, respectively, and the other walls are adiabatic. The effects of Rayleigh number ( Ra = 103—106), Hartmann number ( Ha = 0, 50, and 100), and ratio of the body's length to the enclosure's length ( W/ L = 0.1—0.9) on the temperature and flow fields are analysed. The Prandtl number is assumed to be 0.02 representing a liquid metal. In the casting process, when a magnetic field is introduced, the convection strength is suppressed and this operation leads to a fine grain structure. To find how the average Nusselt number changes, the average vertical velocity in a certain location is also calculated. It was observed that the body's length affects the flow and temperature fields. It was also found that with increasing the W/ L, heat transfer decreased at low Rayleigh numbers but increased at the beginning and then decreased at high Rayleigh numbers.