Numerical study of isothermal gas-liquid two-phase bubbly flow

With the development of computer capability and advancement of modelling software, the technology of computational fluid dynamics (CFD) has been gradually recognized and utilized in engineering field to help seeking practical industrial solutions of gas-liquid two-phase flow. Among various numerical models for two-phase flow, the two-fluid model which traces two phases separately by using two sets of transport equations can be considered as the most accurate one. However, the numerical descriptions of interfacial actions bridging these two phases become to critical aspects to transport equations. The interfacial process descriptions named closure terms generally include three aspects, referred as turbulence model, interfacial driving force and interfacial area concentration (interfacial area per unit). In current study, the capability of Two-fluid model and its closure terms has been investigated to simulate vertical and horizontal bubbly flow conditions. An additional population balance model has been adopted to trace the interaction mechanisms between bubbles/bubbles and bubbles/eddies. There are three major aims for this current work: i) to assess the capability of an experimental drag coefficient correlation in terms of local void fraction and to compare this model with Ishii-Zuber drag coefficient model. ii) to estimate the performance of population balance model-Average Bubble Number Density (ABDN) model on horizontal bubbly flow where the internal local parameters are highly asymmetrically distributed along the radius direction. iii) to value the qualification of recently developed Direct Quadrature Methods of Moments (DQMOM) model which transforms the description of Particle Size Distribution (PSD) problem into lower-order moments of the size distribution (Cheung et al 2009 b)