Effects of heater location and heater size on the natural convection heat transfer in a square cavity using finite element method

Finite element method was used to investigate the effects of heater location and heater size on the natural convection heat transfer in a 2D square cavity heated partially or fully from below and cooled from above. Rayleigh Nu(m)ber (5x10(2) a parts per thousand currency sign Ra a parts per thousand currency sign 5x10(5)), heater size (0.1 a parts per thousand currency sign D/L a parts per thousand currency sign 1.0), and heater location (0.1 a parts per thousand currency sign x(h)/L a parts per thousand currency sign 0.5) were considered. Nu(m)erical results indicated that the average Nusselt Nu(m)ber (Nu(m)) increases as the heater size decreases. In addition, when x (h)/L is less than 0.4, Nu(m) increases as x (h)/L increases, and Nu(m) decreases again for a larger value of x (h)/L. However, this trend changes when Ra is less than 10(4), suggesting that Nu(m) attains its maximum value at the region close to the bottom surface center. This study aims to gain insight into the behaviors of natural convection in order to potentially improve internal natural convection heat transfer.