INFLUENCE OF THE ASPECT RATIO AND LOCATION OF AN ISOTHERMAL BLOCK ON THE BUOYANCY-INDUCED HEAT TRANSFER IN AN ENCLOSURE

Abstract

The objective of the current study's numerical analysis is to find the effect of the aspect ratio and placement of an isothermal block on fluid flow and heat transfer within an air-filled square cavity and having a Prandtl number of 0.71. The flow is considered to be taking place by natural convection and Rayleigh's numbers range between 10<sup>3</sup> and 10<sup>6</sup>. Between 1.00 and 2.00, the block's aspect ratio is evaluated. In a cavity with a centrally positioned hot block, the impact of Rayleigh's number and block aspect ratio on heat and fluid transport is evaluated. The effect of the location of the block is examined at three different locations as the top wall, center, and bottom wall of the cavity, respectively. A finite-difference-based stream function vorticity formulation is considered for the computation. The findings indicate that Rayleigh's number is a positive function of the heat-transfer rate and fluid velocity which shows that increase in Ra enhances buoyancy. The increase in the aspect ratio of the internal block enhances the area of hydrodynamic blockage, which modifies the rate of convection and flow velocity of the fluid within the cavity. The results also show that shifting the block's location has a significant impact on the buoyancy force generated inside the enclosure. A higher total heat transmission rate is produced by the bottom and center-placed blocks.