General guideline for closure model development for gas-liquid flows in the multi-fluid framework

• Published in: Nuclear engineering and design Vol. 357; p. 110396
• Main Authors: Lucas, D., Krepper, E., Liao, Y., Rzehak, R., Ziegenhein, T.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01-02-2020; Elsevier BV
• Subjects: CFD; Closure models; Computational fluid dynamics; Computer simulation; Liquid flow; Multi-fluid model; Nuclear accidents & safety; Nuclear engineering; Nuclear reactors; Nuclear safety; Reactor safety; CFD; Closure models; Multi-fluid model
• ISSN: 0029-5493; 1872-759X
• DOI: 10.1016/j.nucengdes.2019.110396

The two- or multi-fluid approach is frequently used for Nuclear Reactor Safety (NRS)-related simulations of gas-liquid flows. To enable reliable predictions the closure models have to reflect the involved local physical phenomena at the non-resolved scale properly. To consolidate the CFD-modelling in the frame of the multi-fluid approach the so-called baseline model strategy was recently proposed (Lucas et al., 2016). The present technical note discusses a long-term strategy for the baseline model development and ways to obtain or improve closure models. Guidelines for the model development are given by listing requirements for appropriate closure models as well as frequently made mistakes. This is illustrated by examples for recent developments done for HZDR baseline models for poly-disperse bubbly flows.