MultiMorph - A Morphology-Adaptive Multifield Two-Fluid Model
2024-06-12 , Munkholmen/Kristiansten

Numerical Simulation, Industrial Application, Euler-Euler, Morphology-adaptive approach, OpenFOAM, gas-liquid flows


Industrial multiphase flows are typically characterized by coexisting morphologies. Modern simulation methods are well established for dispersed (e.g., Euler-Euler) or resolved (e.g., Volume-of-Fluid) interfacial structures. A simulation method that requires less knowledge about the flow in advance would be desirable and should allow describing both types of interfacial structures – resolved and dispersed – in a single computational domain. Such methods that combine interface-resolving and non-resolving approaches are called hybrid models. A morphology adaptive multifield two-fluid model, named MultiMorph Model, is proposed, which is able to handle dispersed and resolved interfacial structures coexisting in the computational domain with the same set of equations. For large interfacial structures an interfacial drag formulation is used to describe them in a volume-of-fluid-like manner. For the dispersed structures, the baseline model developed at Helmholtz-Zentrum Dresden - Rossendorf e.V. (HZDR) is applied. The functionality of the framework is demonstrated by several test cases, including a single rising gas bubble in a stagnant water column. Recent developments focus on the transition region, where bubbles are over- or under-resolved for Euler-Euler or for Volume-of-Fluid, respectively. The contribution will focus on an overview about the fundamentals of the MultiMorph Model and recent simulation results for a plunging jet, a stratified counter-current air-water flow and a column tray of a distillation column. The figure shows the numerical simulation of a plunging jet with the MultiMorph model with marked morphologies and phase transition regions.

Helmholtz-Zentrum Dresden-Rossendorf e.V., Bautzner Landstr. 400, 01328 Dresden, Germany

Since 2012 I am employed at the Reactor Engineering Division of Jožef Stefan Institute, Ljubljana, Slovenia. Major research interests include computational fluid dynamics of flows relevant for safety of nuclear reactors, focusing on modelling of two-phase flows.