Numerical Simulation of a Binary Fluid Behavior Subjected to the Coupling Between Natural Convection and Thermodiffusion in a Partially Wavy Cavity

The current numerical study aims to analyze the hydrodynamic, thermal, and mass transport behavior of a binary fluid under natural thermal convection and thermodiffusion within a modified horizontal rectangular cavity. The cavity is heated either from the bottom or the top, with isothermal, impermeable, and partially wavy horizontal walls. The simulation is based on the finite element method applied to the differential equations governing the coupling of natural convection and thermodiffusion. The results reveal that partial wall undulations significantly affect the binary fluid flow, leading to species migration toward the perfectly insulated vertical walls. The numerical analysis of the mass field of the studied fluid clearly indicates that the lateral species separation intensifies with bottom heating, increased undulated length, and greater wave amplitude. These geometrical parameters also significantly impact heat transfer, as characterized by the Nusselt number.