Numerical Investigation of Segregated and Coupled Solvers for Falling Film Flows

This study investigates the numerical performance of segregated and coupled approaches for simulation of falling film flows. The foam-extend default solver, interTrackFoam, is used as a segregated solver and a coupled one is developed for comparison. The developed Coupled solver algorithm is also presented belong side the interface tracking algorithm and grid displacement functions. By incorporating the mathematical models of physical quantities including, surface tension, gravitational force, and interfacial interactions, the coupled solver allows for a comprehensive analysis of film thickness, velocity distribution, and pressure drop within the system. The capabilities of the default and coupled solvers to capture the complex dynamics of liquid films is demonstrated through cases with three excitation frequencies of fr = ۰.۱۵, ۰.۰۷۹ and ۰.۰۵. Alongside the coupled solver, an efficient mesh motion method is used and implemented for passing through the mesh problems. Residual plots are provided for both aforementioned solvers. These plots, which are in terms of time and iteration numbers, well represent the convergence behavior. Regarding the performance of two solvers, the results shows better performance of segregated approach for solving the unsteady falling film flows. Segregated approach have at least three times faster overall computational speed. The high speed and the ability to separately control the convergence of pressure and velocity, have made the segregated solver suitable for unsteady falling film flows.

کلیدواژه ها:

Unsteady Falling Film ، Coupled Solver ، Free Surface ، Finite Volume Method ، InterfaceTracking