Multifield Hybrid Approach For Bubble To Slug Flow Transition Modelling
Free (open access)
263 - 273
R. Denefle, S. Mimouni, J.-P. Caltagirone& S. Vincent
This paper aims to assess a conservative interface locating method based on levelset adapted to two fluid model for two phase flow. The objective of the work is twofold: first to check out the prediction of the model on bubble coalescence cases and then to introduce a first description of the multifield hybrid approach for twophase flow modelling. The interface locating method is part of a model dedicated to the simulation of large and distorted bubbles. At different liquid viscosities and densities, the model yields reasonable predictions of terminal velocities and shapes for rising bubble experiments. The overall method relies also on an existing building block, consisting of a set of averaged models dedicated to dispersed bubbles, which has already been validated and has given a reasonable agreement with experimental data in cases where the spherical shape assumption is still valid for the dispersed phase. As a consequence, we present the first step toward a new approach consisting of modelling the small bubbles as a dispersed field and simulating the large and distorted ones. The main outcome is the simulation of bubble coalescence where the distortion of the interface during the coalescence phenomena is followed. The capability to simulate correctly coalescence phenomena is an important point of the modelling of slug flows with interface locating methods. Keywords: multifield model, surface tension, interface sharpening, bubble rising, coalescence. 1 Introduction Two-phase flows are featuring many industrial applications such as nuclear power plants, heat exchangers and chemical reactors. Based on the interface structure,
multifield model, surface tension, interface sharpening, bubble rising,coalescence.