An experimental investigation on forced convection heat transfer of single-phase flow in a channel with different arrangements of porous media

Abstract

Nowadays, heat transfer in porous zone plays an important role in many industrial and modern applications. For this reason, issues related to porous media are important in the design and analysis of heat exchangers. In this study, a single-phase flow of air in channel having circle cross-section with different arrangements of porous media is experimentally studied. Changes in hydrodynamic parameters, improvement of heat transfer by porous media in the channel as well as pressure drop resulted from porous media are considered. Results from these experiments show that presence of porous media leads that the thermal flux applied to walls of channel be transferred into fluid due to creating a uniform space and high conductivity of porous media. Also, the mean temperature of the fluid increases and this leads to decrease temperature difference between channel wall and the mean temperature of the fluid. Because of the heat transfer coefficient has an inverse relationship with the temperature difference between the walls of the channel and the mean temperature of the fluid, the heat transfer coefficient increases. For investigation the heat transfers with pressure drop simultaneously, heat transfer performance ratio and heat transfer enhancement ratio are defined. The results of this study show that fully filled channel of porous media has the best heat transfer enhancement (in both laminar and turbulent flows). In turbulent flow, channel with annulus shape porous zones (the porous zone inserted adjacent to wall) has the best thermal performance that means has the large value of heat transfer with low pressure drop.