New Implementations of Surface Tension Forces for PLIC-VOF Methods

A comparative study has been carried out between different models of implementing surface tension for PLIC-VOF methods: i) the well known Continuum Surface Force (CSF); ii) Staggered Grid Interface Pressure (SGIP); iii) Modified Meier’s. As main difference with respect the CSF model, the two last use information of the interface location for the calculation of the surface tension forces, therefore, they need a model of interface reconstruction. The models will be tested under static and dynamic conditions, for the case of a drop and bubble between water and air. In order to reduce the ‘parasitic’ currents that is characteristic of this type of models, two different strategies are used: i) a new method for the calculation of the interface curvature based on the use of polar coordinates; ii) the use of kernels for smoothing the jump of the colour function and the interface. Additionally, the influence of the order of accuracy of the reconstruction algorithms employed that affect the curvature estimation and the surface tension force calculation is also checked. After testing the different cases, it can be concluded that SGIP and modified Meier perform in a comparable way, and much better than CSF model without kernel, that is only competitive with the use of the kernels. However, modified Meier is preferred respect SGIP due to its straitghforward implementation on unstructured meshes.