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Multiphase Science and Technology
SJR: 0.124 SNIP: 0.222 CiteScore™: 0.26

ISSN Imprimir: 0276-1459
ISSN En Línea: 1943-6181

Multiphase Science and Technology

DOI: 10.1615/MultScienTechn.v23.i2-4.30
pages 129-164

CFD MODELING OF ADIABATIC BUBBLY FLOW

Eckhard Krepper
Christophe Morel
Commissariat a l'Energie Atomique, DEN/DM2S/STMF/LMSF, 17; rue des Martyrs, 38054, Grenoble, Cedex 9, France
Bojan Niceno
Laboratory for Thermal Hydraulics, Department of Nuclear Energy and Safety, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
Pierre Ruyer
Institut de Radioprotection et de Surete Nucleaire, CE Cadarache, Bat. 700, BP 3-13 115 Saint Paul lez Durance Cedex, France

SINOPSIS

This paper describes the simulation of adiabatic gas-liquid flow based on the Eulerian approach. An adequate characterization of the momentum exchange between the phases is necessary. The basic experiment investigating the momentum exchange is vertical upward flow in a pipe. This paper describes the main computational fluid dynamics (CFD) approaches for momentum exchange and the comparison to experimental results for several test conditions. For large gas-injection rates, a bubble size distribution including bubble coalescence and fragmentation has to be considered. The paper describes the concept of the inhomogeneous multiple size group model MUSIG, developed by ANSYS/CFX and Helmholtz-Zentrum Dresden-Rossendorf (HZDR), which is implemented in the CFD-code CFX, and a comparable concept of a population balance model implemented in NEPTUNE CFD [Commissariat a l'Energie Atomique (CEA), Électricit é de France (EDF), Institut de Radioprotection et de S ûret é Nucl éaire (IRSN) and AREVA]. Measurements performed at HZDR are used for model validation. Crucial for the quality of the models described are the base approaches for bubble coalescence and fragmentation. Among other influences, these phenomena depend on the level of liquid turbulence. Therefore special attention was devoted to CFD simulation of bubbly turbulent flow based on different model concepts. Concepts based on Reynolds-averaged turbulence models are described. At the Paul Scherrer Institute, large eddy based studies were performed and compared to DEDALE experiments. The work was performed within the NURESIM and NURISP projects under the 6th and 7th European Framework Program.