Parametric Study of Heat Transfer in Water–Alumina Nanofluid Flow Inside Porous Tube with Multiple Heat Sources

In this problem, heat transfer and the flow of water–alumina nanofluid inside a porous tube was studied. The constant heat flux was applied by three heat sources at different locations. The aim of this study was to find the optimal location for the three mentioned heat sources in order to facilitate heat transfer. Also the effects of Reynolds number (flow velocity), pipe porosity and different volume fractions of alumina nanoparticles in water on heat transfer were investigated. It was found that as the distance of other heat sources from the first heat source increases, the wall temperature reduces and therefore, for the same heat flux, the heat transfer coefficient and Nusselt number increase and heat transfer is improved. Also, it is observed that increasing the pipe porosity does not affect the temperature of the fluid mass at the outlet. In addition, by increasing the volume fraction of alumina nanoparticles, and heat transfer improves, but the bulk temperature at the outlet decreases, which is due to the significant increase in the mass flow rate of the inlet fluid with the addition of alumina nanoparticles.