Publications Repository - Helmholtz-Zentrum Dresden-Rossendorf

1 Publication
Comparative simulations of bubble entrainment cases with NURESIM_CFD and CFX-11
Schmidtke, M.; Lucas, D.;
This progress report presents the work done for the numerical prediction of the plunging jet configuration. A study case is simulated with both the NURESIM_CFD_1.0.5 code and with CFX-11 and the results for the gas entrainment near the jet are compared. In the frame of an Euler-Euler simulation, the local morphology of the phases has to be considered in the drag model. For example the air is a continuous phase above the water level but bubbly below the water level. In this study the SIMMER model is applied for the drag. This model assumes bubbly flow where the gas void fraction is low and droplets in air, where the gas void fraction is high. The influence of the drag model and particle diameters for droplets and bubbles on the gas entrainment is studied.
For the drag, the Grace law (constant drag coefficient) and the Schiller Naumann law are tested. The particle diameter also has an influence on the drag. A variation of the drag force does not have an obvious effect on the gas entrainment in the simulations performed with the SIMMER model. The gas entrainment is overestimated in all simulations and there is no free parameter inside the SIMMER model which allows an adjustment of the entrainment in the simulation.
Keywords: Bubble entrainment, jet, impinging, plunging, PTS, ECC
  • Article, self-published (no contribution to HZDR-Annual report)
    Forschungszentrum Rossendorf 2008
    12 Seiten

Publ.-Id: 11720 - Permalink