Effect of Prandtl Number on Free Convection in a Solar Collector Filled with Nanofluid

Numerical study of the influence of Prandtl number on free convection flow phenomena in a solar collector having glass cover plate and sinusoidal absorber is done. The working fluid is water-Al2O3 nanofluid. The cover plate has initially constant temperature Th, while bottom absorber is at temperature Tc, with Th > Tc. The remaining walls are considered adiabatic. By Penalty Finite Element Method the governing differential equations with boundary conditions are solved. The effect of the Prandtl number on the flow pattern and heat transfer has been depicted. Comprehensive average Nusselt number, average temperature and mean velocity inside the collector are presented as a function of the governing parameter mentioned above. The highest Pr causes the greatest heat transfer. The enhancing performance of heat transfer rate is more effective for the water-Al2O3 nanofluid than the base fluid.