CFD modelling of adiabatic bubbly flow


CFD modelling of adiabatic bubbly flow

Krepper, E.; Morel, C.; Niceno, B.; Ruyer, P.

The paper describes the simulation of adiabatic gas-liquid flow based on the Euler/Eulerian approach. An adequate characterisation of the momentum exchange between the phases is necessary. The basic experiment investigating the momentum exchange is the vertical upward flow in a pipe. This report describes the main 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 MUSIG model, developed by ANSYS/CFX and HZDR which is implemented in CFX and a comparable concept of a population balance model implemented in NEPTUNE_CFD (CEA, EDF, IRSN and AREVA). Measurements performed in HZDR are used for model validation. Crucial for the quality of the described models are the base approaches for bubble coalescence and fragmentation. Among other influences these phenomena depend on the liquid turbulence. Therefore special attention was devoted on CFD simulation of bubbly turbulent flow based on different model concepts. Concepts based on Reynolds averaged turbulence models are described. In PSI Large Eddy based studies were performed and compared to DEDALE experiments. The work was performed within the NURESIM and the NURISP projects in the frame of sixth and the seventh European Framework Program.

Keywords: CFD; multiphase-flow; adiabatic flow; polydispersed flow; turbulence; experiments; simulations

Permalink: https://www.hzdr.de/publications/Publ-15508
Publ.-Id: 15508