Effects of Microstructure on Three-Dimensional Double-Diffusive Natural Convection Flow of Micropolar Fluid

This work presents a three-dimensional numerical study on double-diffusive natural convection in a cubic cavity filled with a micropolar fluid. The flow is driven by buoyancy forces due to temperature and solutal gradients. Constant temperature and concentration are imposed along the two vertical sidewalls of the cubic enclosure, while the remaining walls are adiabatic and impermeable. The governing equations are expressed in the vorticity-stream function formulation and then solved numerically using the control volume finite method. Numerical results are compared with the case of a Newtonian fluid. The influences of the micro-constituents of the micropolar fluid are depicted. The results show different transitions of the structure of the main flow when varying the vortex viscosity parameter. It is also observed that both the heat and mass transfer rates and the three-dimensional character of the flow are reduced by increasing the vortex viscosity parameter.