CONVECTIVE HEAT TRANSFER IN A SQUARE CAVITY WITH EMBEDDED CIRCULAR HEATED BLOCK AT DIFFERENT POSITIONS

Finite element method is adopted in analyzing a two dimensional partial differential equations of Navier Stokes that governs mass, momentum and energy for a convective heat transfer problem within a square cavity. The cavity walls kept at constant cold temperature except for the right wall being adiabatic. With an embedded circular heated block located in the cavity, simulations are performed to determine the effect of the position of the block at the top, middle and bottom of the cavity on natural convection. The experiments are carried out for different values of Rayleigh number varying from 10(3)-10(6) by using a COMSOL multiphysics software. The results are obtained in terms of streamline formation, temperature contours as well as Nusselt number. The results show that the position of the embedded hot circular body is strongly dependent on the fluid flow characteristics and thermal fields within the cavity. At a fixed Rayleigh number, the heat transfer coefficient dramatically increases when the circular heated block is embedded at the top position of the cavity and Nusselt number reaches the maximum around the hot circular block either at the top, middle or bottom position of the embedded body inside the cavity.