This research was undertaken by Julian Mindel during his PhD studies at Imperial College under the supervision of Dr. J-P Latham and Prof. Chris Pain, with assistance from AMCG’s Dr. Gareth Collins, Dr. Gerard Gorman, Dr. Matt Piggott and Dr. Jiansheng Xiang.
In the simulation of the collapsing water column, the adaptive mesh optimization works well with the turbulence capturing and interface tracking to produce realistic looking waves and bubbles.
Given the intent to model the dynamics of two immiscible fluids, it is necessary to simulate the evolution of the interface between them in a sharp, conservative, and efficient way. A concentration scalar field is defined on the computational domain, and its evolution is governed by a pure advection equation. Even though pure advection equations involve no diffusion terms, smearing of the interface is still observed due to numerical diffusion. The methods developed during the VGW project overcome this obstacle. Leonard’s Hyper-C advection scheme (Leonard, 1991) is implemented into Fluidity through a Control Volume Finite Element (CVFEM) discretisation. The resulting method was found to successfully allow for sharper and more accurate interface definitions at a low expense when compared to other methods such as volume of fluid (VOF), or level set methods (LSM). In the latest version of Fluidity, further improvements have been made to define sharply the interfaces.
See Publications for access to Mindel’s PhD.