Abstract
In this study, the effects of Richardson and Hartmann numbers on heat and mass transfer in a three-dimensional lid-driven cubical cavity subjected to a uniform magnetic field are investigated numerically. The lid is maintained at constant high temperature and is moving downwards in the negative y-direction. The wall opposite to the lid is stationary and maintained at constant low temperature, and all other walls are kept adiabatic. Entropy generation is also calculated to investigate the nature of irreversibility in heat transfer inside the cavity. The computations are performed for the Richardson numbers 10 and 100, and Hartmann number in the range between 0 and 80. Prandtl number and the irreversibility coefficient are considered constant and given the values 0.054 and 10(-4), respectively. It was found out that the average Nusselt number decreases when the Hartmann number increases for all values of the Richardson number. Also, the Bejan and average Nusselt numbers have a converse relationship for the same range of Hartmann and Richardson numbers. In addition, the study shows that for all the considered cases, the entropy generation rate decreases with increasing the Hartmann number.