Investigação numérica da convecção natural de canal poroso heterogêneo aquecido por baixo

Abstract

This work consists of natural convection study on a heterogeneous horizontal channel heated from below. The channel is filled with solid, squared, disconnected, condutive and uniformly distributed blocks. In the side walls we consider periodic boundary condition, and the numerical simulation is done through the solution of momentum, energy and continuity equations. The range of the parameters used is as follows: Rayleigh number Ra = 10, 10, number os blocks N = 1, 4, 16 , aspect ratio ( A = 2, 3, 4, 6, 8 ). We evaluate the influence of these parameters in the Nussel number, to measure the average heat transfer, and in the maximum streamline value, to quantify the fluid recirculation intensity. We proceed by analysing the streamlines, isotherms and temporal Nusselt. In general , the increase in the aspect ratio promotes more freedom to the plume development, therefore increasing the Nusselt number. The presence of the geometric obstacles limits the flow’s degrees of freedom, therefore decreasing total heat transfer.