Numerical investigation of convective heat transfer in a rectangular vented cavity with two outlets and cold partitions

Abstract

The convective flow in a ventilated cavity having two outlets and one inlet is numerically investigated. Introducing cold partitions inside the cavity modifies heat and fluid flow characteristics. It is analyzed by placing a single and double partition inside the cavity. Three configurations of the rectangular cavity are analyzed in the laminar flow range, with Rayleigh numbers varying between 103 and 106. The Navier Stokes equation, which governs the flow, is solved using the finite difference method. The medium of flow is considered as air with Prandtl number 0.71. The result shows that the fluid entering the inlet splits into two to enter the two outlets, and this cold air occupies most of the central place of the cavity at higher Ra when there is no partition in the enclosure. With the introduction of cold sections, a part of fluid gets attracted towards it and creates fluid circulation. It decreases the velocity of the fluid at the bottom of the cavity at the midsection of outlet 2. The fluid velocity at outlet 1 is not much affected. The average heat transferred to the right wall gets significantly decreased due to the cold partitions at lower Rayleigh numbers, but there is an increase in the overall average Nusselt number of all outer walls. A correlation equation that gives the relationship between Nusselt number and Rayleigh Numbers is developed. The study presents the variation of isotherms, streamlines, velocity, rate of heat transfer and correlation of Nu for the considered problem.