A SPH multi-resolution framework for multi-phase flows

• A multi-resolution SPH Framework for multi-phase flows was developed. • A novel reconstruction scheme enables consistent phase interphase transport across different resolution levels. • Static refinement regions can be used without following the interface, reducing computational cost. • The proposed model shows good agreement with established reference solutions. Smoothed Particle Hydrodynamics (SPH) is a particle method frequently employed for the prediction of multi-phase flows in technical applications. The development of accurate and efficient multi-resolution SPH is considered a so-called Grand Challenge by the SPH community, and significant efforts have been made to address this issue. Unfortunately, especially for multi-phase flows, available approaches are scarce. This is due to another challenging aspect, the transport of a discontinuity inherent to this kind of flow: the phase interface. Up to now, no multi-resolution approach is available that is capable to transport and preserve this discontinuity across different resolution levels. To this end, a novel framework was developed that incorporates a domain-decomposition approach, a state-of-the-art particle generation and deletion algorithm, as well as a reconstruction of the phase interface at the internal boundary. The framework is applicable and tailored to multi-phase flows since it allows surface tension effects to be accounted for across different resolution levels. Its capabilities are evaluated by several benchmarks, proving good agreement to the reference results. Finally, the multi-resolution framework is demonstrated in an application-relevant atomizer case.