Numerical study on performance enhancement of a square enclosure with circular cylinder of varying geometries

Abstract

Extensive use of electronic components produces a lot of heat, and due to this heat the efficiency of the component degrades. To overcome this issue, a proper heat dissipation is needed, and this can be carried out using natural convection. This paper presents the numerical investigation of the heat transfer and flow characteristics from a hot cylinder body, which is in a square enclosure using natural convection. The numerical study was carried out in a 2D simulation for three Ra i.e. 104,105 and 106. By referring several literatures, in this study a change in the geometry is done. Two cases are considered in which the geometric modification of the cylinder is done. In the first case, the upper half of the cylinder is semicircle in shape and the lower half is varied by arc lengths of 0 mm, Y mm, 2Y mm, 3Y mm, 4Y mm and 5Y mm and in the second case the upper half is varied by arc lengths of 0 mm, Y mm, 2Y mm, 3Y mm, 4Y mm and 5Y mm and the lower half is a semicircle. This change in geometry defines the fluid movement inside the enclosure and helps to study the Nusselt number with respect to the Rayleigh number for different geometries. Thus, there is an increase in the fluid movement between the cylinder and the square enclosure, and therefore, this helps in significant heat transfer from the cylinder body. The most optimum results were found when the upper half of the cylinder is a semicircle and the lower half has an arc radius of 0 mm, i.e. case 1:0 mm, the results depicted a 11.37% increase in the heat transfer rate and in case 2 the maximum increase in heat transfer rate was 4.58%, which was shown by the geometry having 2Y mm arc radius on the upper half.