Natural Convection from Discrete Heat Sources Placed in Wavy Enclosure

Abstract

The effect of sinusoidal corrugated upper surface for enclosure on the heat transfer by natural convection from two heat sources placed on the bottom surface of the enclosure has been studied. The two heat sources constant and high temperature, length of each heat source (10%) from the total length of bottom surface, the distances that do not contain heat source on the bottom surface thermally insulated, temperature of verticals walls and upper surface low and constant. corrugating upper surface was change the dimensional corrugation amplitude between (0.1-0.3), for number of corrugations (3), the dimensional distances between the two heat sources were change between (0.2-0.8), the Rayleigh numbers ranged between (103 ≤ Ra ≤ 105), the fluid inside the enclosure was air Prandtl number for it (0.7). were analyzed flow and temperature fields inside the enclosure numerically by solving Navier Stokes and Energy Equations, have been used Cartesian velocity components and pressure on a collocated grid are used as dependent variables in the momentum equations which discretized by finite volume method, body fitted coordinates are used to represent the geometry shape of the problem accurately, were grid generated technique based on elliptic partial differential equations, SIMPLE algorithm is used to adjust the velocity field to satisfy the conservation of mass. The results showed the increase in the magnitude of dimensional distance between two heat sources lead to increased average Nusselt number for all values of Rayleigh numbers (103 ≤ Ra ≤ 105), as are the highest value of the average Nusselt number at dimensional distance (0.8) and less value at the dimensional distance (0.2), the dimensional distance (0.6) is a special case when the Rayleigh number equal (105) as at least average Nusselt number from the remaining values of the two dimensional distances (0.2) and (0.4), as the average Nusselt number increases with increasing dimensional corrugation amplitude for the number of corrugations (N=3) for dimensional distance (0.8), as well as comparing numerical results showed good agreement with published results.

Keywords

• Heat sources
• Wavy enclosure