Entropy Generation and Natural Convection of Air under a Magnetic Quadrupole Field in a Square Enclosure

Abstract

The natural convection and entropy generation of air are numerically investigated in a two-dimensional square enclosure under a magnetic quadrupole field. In this study. The finite-volume method is applied to solve the coupled equation for flow, energy and entropy generation. Simulations are conducted to obtain solutions in terms of streamlines, isotherms, local entropy generation contours, total entropy generation, Bejan number for various ranges of the magnetic force parameter and Rayleigh number in a nongravitational field. Two symmetric cells with the same strength but opposite rotation directions are observed with the flow filed. Total entropy generation increases with increasing the magnetic force number. However, the average Bejan number holds the reverse trend. The magnetic field has a broad spectrum of applications in engineering areas to control natural convection. The local and total entropy generation presented in this study can be useful addition where one wants to minimize the irreversibility of the system.