Double diffusion in a combined cavity occupied by a nanofluid and heterogeneous porous media

Abstract

The aim of the present study is to simulate double diffusion in a circular cylinder over a rectangular cavity by utilizing incompressible smoothed particle hydrodynamics (ISPH) method. An originality of this study is adopting the ISPH method in simulating double diffusion in a novel domain of a circular cylinder over a rectangular shape occupied by Al2O3{{\rm{Al}}}_{2}{{\rm{O}}}_{3}–H2O{{\rm{H}}}_{2}{\rm{O}} and heterogeneous porous media. The variations of Darcy parameter (Da) between 10−31{0}^{-3} and 10−51{0}^{-5} with two levels of porous media, (0≤η1=η2≤1.5)(0\le {\eta }_{1}={\eta }_{2}\le 1.5), Rayleigh number (103≤Ra≤105)(1{0}^{3}\le {\rm{Ra}}\le 1{0}^{5}) with variable buoyancy ratio parameter (0≤N≤2)(0\le N\le 2), solid volume fraction ϕ\phi between 0 and 0.05, and Lewis number (10≤Le≤40)(10\le {\rm{Le}}\le 40) on the features of heat/mass transport as well as velocity field are discussed. It is found that the homogeneous porous medium reduces the temperature and concentration within a combined cavity. A decrease in Darcy parameter from 10−21{0}^{-2} and 10−51{0}^{-5} suppresses the maximum of a nanofluid velocity by 75% regardless the levels of porous media. An increase in parameters Ra and N enhances the heat and mass transmission, as well as the nanofluid velocity. Adding more concentration of nanoparticles until 5%5 \% reduces the nanofluid velocity. The variations of boundary conditions are acting effectively in changing the temperature and concentration circulations within a combined cavity. Besides, the variations of boundary conditions change the maximum of the velocity field by 86.9%.

Keywords

• circular cylinder
• double-diffusion
• isph method
• homogeneous/heterogeneous porous media
• nanofluid