Prandtl Number Effect on Nanofluid Flow Inside A Porous Cavity
The problem of lid-driven flows in cavities has been major topic for research studies due to its fundamental nature and owing to the wide spectrum of engineering applications such as electronic device cooling, crystal growth, high-performance building insulations, multi shield structures used for nuclear reactors, food processing, float glass production, solar power collectors, furnace, drying technologies, etc. In this article Numerical study of the effect of Prandtl number on nanofluid flow inside a porous cavity in a two-sided lid driven square closure is studied. The working fluid is Cu/water nanofluid. By Finite Element Method the governing partial differential equations are solved. The highest Pr causes the greatest heat and mass transfer. The enhancing performance of heat and mass transfer rate is more effective for the water-Cu nanofluid than the base fluid. It is assumed that the temperature difference driving the mixed convection comes from the side moving walls, when both horizontal walls are kept insulated. In this research, the effect of Prandtl number from 0.71 to 10 on nanofluid flow is investigated. The values of Richardson number, solid volume fraction of water/Cu nanofluid, Darcy number are kept fixed as 10, 2% and 0.01 respectively. The phenomenon is analysed through streamlines, isothermal lines, iso-concentration lines plots, with special attention to the Nusselt number and Sherwood number. It is found that heat- mass transfer becomes higher by using water/Cu nanofluid than clear water.
Keywords- Mixed convection; porous cavity; nanofluid; finite element method; Prandtl number.