The Surface Tension Challenge in Air-Water Interfaces using the Volume-of-Fluid Method

摘要

The steadily increasing computing power, challenges modern CFD codes to take into account phenomena that are important in smaller scales. Specifically in naval engineering, modeling of spray/foam resistance phenomena or modeling the air-water interface behavior in air-assisted methods for drag reduction (air-cavity method, air-lubrication method), could prove of major importance in the pursuit of a more efficient ship. To this end, surface tension is an important phenomenon for inclusion in the CFD simulations. In the literature, one comes across a large variety of different surface tension modeling approaches that can be directly coupled with a volume-of-fluid code. Although the performance of surface tension methods is traditionally demonstrated in static bubble test cases with exotic fluids, their numerical behavior is altered when an air-water interface is considered. This is due to large differences in the fluid density and viscosity. The purpose of this work is to demonstrate the numerical difficulties encountered in certain surface tension methods, discuss their strong and weak points in steady and unsteady simulations and propose new alternatives.