Integrated Approach to Multiphase Flow Regime Prediction Through Computational Fluid Dynamics CFD

Abstract

This paper presents recent advances in multiphase modelling methods in Computational Fluid Dynamics (CFD). It uses case studies to show how integration of advanced multiphase modelling approaches can improve the fidelity and realism of simulation of separation and process systems; helping improve design and performance. CFD has been widely used to aid the design and operational performance of many separation and multiphase production and process systems; often providing significant insight and performance improvement. Traditionally, numerous compromises or simplifications must be made when simulating complex multiphase flows and their transitions within production and separation systems using CFD. For example, the modelling methods applicable to capture gas-liquid or liquid-liquid interface behaviour are not suitable (or practical) to also capture gas columns, liquid films or liquid entrainment phenomena, that may be important to quantifying overall system performance. To accommodate different multiphase phenomena and flow regimes, multiple CFD simulations or approaches have often been required. This can limit the insight or fidelity of a given simulation or, in some cases, mean overall performance cannot be fully quantified (even though useful performance indicators may still be identified). Here, the authors present advances in hybrid multiphase modelling and how integration of multiphase modelling approaches enables multiple multiphase flow regimes and their transition to be captured through CFD simulation. The paper will demonstrate how these advances enables simulation of more complex behaviours with increased fidelity. Examples, case studies and validation cases are presented demonstrating phenomena including bulk liquid interface break-up, liquid film formation and entrainment of droplets plus their break—up and deposition. The examples will be presented in the context of the improvements possible in simulation fidelity and realism, of multiphase systems, and how this can impact the insight and value gained from CFD simulation in this complex field. The work presented shows how new developments and evolution of CFD-based predictions can advance how the industry uses this approach and the value that can be obtained. It highlights how integration of the most advanced modelling approaches and methods is key to the next stage of application of CFD to enable better representation of the full range of fluid mechanics that are critical to many separation and multiphase system designs and performance.