Versatile surface tension and adhesion for SPH fluids

Abstract

Figure 1: A water crown emerges as a result of the impact of a water droplet into a filled container. Our surface tension force allows realistic simulation of such natural phenomena. AbstractRealistic handling of fluid-air and fluid-solid interfaces in SPH is a challenging problem. The main reason is that some important physical phenomena such as surface tension and adhesion emerge as a result of inter-molecular forces in a microscopic scale. This is different from scalar fields such as fluid pressure, which can be plausibly evaluated on a macroscopic scale using particles. Although there exist techniques to address this problem for some specific simulation scenarios, there does not yet exist a general approach to reproduce the variety of effects that emerge in reality from fluidair and fluid-solid interactions. In order to address this problem, we present a new surface tension force and a new adhesion force. Different from the existing work, our surface tension force can handle large surface tensions in a realistic way. This property lets our approach handle challenging real scenarios, such as water crown formation, various types of fluid-solid interactions, and even droplet simulations. Furthermore, it prevents particle clustering at the free surface where inter-particle pressure forces are incorrect. Our adhesion force allows plausible two-way attraction of fluids and solids and can be used to model different wetting conditions. By using our forces, modeling surface tension and adhesion effects do not require involved techniques such as generating a ghost air phase or surface tracking. The forces are applied to the neighboring fluidfluid and fluid-boundary particle pairs in a symmetric way, which satisfies momentum conservation. We demonstrate that combining both forces allows simulating a variety of interesting effects in a plausible way.

An implicit viscosity formulation for SPH fluids

“…Our approach shares this issue with PBD, where the time dependency of parameters is not handled as timesteps typically do not significantly vary in a scenario (e.g., [Bender et al 2014b]). One of the first papers that discuss resolution-dependent parameters in SPH is, e.g., [Akinci et al 2013]. However, timestep dependencies are not addressed.…”

Fluid Simulation by the Smoothed Particle Hydrodynamics Method: A Survey

“…Particle-air interaction with SPH can be effectively modelled by the calculation of the surfacetension and adhesion forces, which removes the necessity of surface tracking and the use of ghost or virtual particles (Akinci et al, 2013b). Another method applies the generation of air particles where air pockets are likely to be formed in the liquid.…”

“…A method of countering this is through the use of specific surface tension and adhesion forces which do not rely on the introduction of ghost particles (Akinci et al, 2013b). Using SPH to model objects or solids in simulations is also popular, finding use in deformable objects and meshes, and elastic and plastic objects.…”

A Particle-based Dissolution Model using Chemical Collision Energy

“…We calculated the percentage of the volume difference at each frame of both spheres: with our method, this reaches a maximum of 3.4% of the sphere volume, while with the method of (Wojtan et al, 2007;Shin et al, 2010) the low sampled sphere dissolves completely before the high sampled sphere halves in size. The adhesion method of (Akinci et al, 2013) is used to ensure the fluid realistically adheres to the sides of the sphere.…”

“…The reliance of films and games on realistic fluid simulations has led to the popularity of this research topic, with most work in this field focused on the behaviour of fluid itself, such as spray, waves and bubbles Cleary et al, 2007;Busaryev et al, 2012) or the interaction with solids (Batty et al, 2007;Robinson-Mosher et al, 2008;Schechter and Bridson, 2012;Akinci et al, 2013). Comparatively few researchers have tackled the challenging problem of the chemical reaction between fluid and solids, which, under the right conditions, can lead to solid mixing with the liquid: a phenomenon known as dissolution.…”