3.1. Framework
In the present research, two imperative multiphase models of Eulerian-Eulerian and volume of fluid (VOF) are utilized. The VOF method is a proper numerical technique to simulate the two-phase flows. The gas-liquid interface is a critical feature of this modeling. The model can be utilized to make the interface between the phases (a free surface reconstruction technique). This technique is also employed for mass and heat transfer in two-phase flows. In the present work, it was tried to assess the weeping rate of a column armed with Nye trays for the whole system not mainly for the gas-liquid interfaces. Consequently, an Eulerian-Eulerian method was chosen for this work. Here, two sets of transient CFD models in the 3D framework were established to investigate the single and two-phase flows via a full three-dimensional geometry of the circular distillation column. The Eulerian-Eulerian multiphase flow was utilized where the phases are treated as interpenetrating continua. Furthermore, the pressure velocity coupling was incorporated using the SIMPLE algorithm. To solve the transient equations prior to reaching the quasi mode, the time period of 0.002 s was considered. The upwind technique was also used for the advection discretization scheme and second-order backward Euler for integrating the time. The equations of momentum balance, species conservation, and mass conservation were solved but the energy conservation was neglected due to the isothermal system.