A surface tension and wetting model for the d+-SPH scheme

An extension to the delta-plus-SPH scheme is presented which allows to model surface tension including temperature-dependency and wetting. The new model makes use of the surface identification mechanism presented in [Marrone 2010] and refined in [Sun 2017] and combines this procedure with the surface tension scheme described in [Breinlinger 2013]. The effect of Marangoni convection is included by calculating the temperature gradient on the surface according to [Tong 2014]. The model requires only a single fluid phase and is therefore computationally more efficient than surface tension schemes which need an explicit fluid-fluid or fluid-gas interface. The model is parametrized by three physical parameters, namely the surface tension, the change of surface tension with temperature and the contact angle on a substrate.