Presence of a porous medium and the arrangements effects on the performance of an air-cooled heat exchanger: an experimental study for heat transfer and pressure drop

The problem of enhancing heat transfer to create high thermal performance systems has received a lot of interest, and numerous solutions have been proposed by researchers. To maximize heat transfer, a porous medium was utilized inside the heat exchanger in this research. The study looks into the experimental effects of different porous media layouts as well as the influence of flow rates on heat transfer in various configurations. To investigate the enhancement of heat transmission, porous media with porosity percentages ranging from 96.5 to 98.9% were used. For the air travelling inside the shell, volumetric flow rates of 1 and 3 L per minute were used, with Reynolds numbers ranging from 5000 to 40,000. Nusselt numbers, pressure drops, and efficiency values were calculated in the study. The results show that the volumetric flow rate of the working fluid has no effect on heat transfer or pressure drop in the tested Reynolds number range. Notably, in the examined flow regime, the efficiency of the tube without a porous medium outperforms that of configurations with a porous medium. The results show that in this range of Reynolds numbers, the Nusselt number ratio of the converter with a porous medium to the converter without porosity can vary from a 50% decrease (arrangement number one at Reynolds 5000) to a 200% increase (arrangement number four at Reynolds 30,000), emphasizing the importance of the porous medium arrangement. Furthermore, the influence of porosity on pressure drop can be up to 900 times the dynamic pressure, especially when the porosity covers the entire surroundings, whereas other configurations result in lesser pressure drops.