Publications Repository  HelmholtzZentrum DresdenRossendorf
A particlecenteraveraged EulerEuler model for bubbly flow simulations
Lyu, H.; Lucas, D.; Rzehak, R.; Schlegel, F.
An inconsistency exists in bubble force models used in the standard EulerEuler simulations. The bubble force models are typically developed by assuming that the forces act on the bubbles' centers of mass. However, in the standard EulerEuler model, each bubble force is a function of the local gas volume fraction because the phaseaveraging method is used. This inconsistency can lead to gas overconcentration in the center or near the wall of a channel when the bubble diameter is larger than the computational cell size. Besides, a meshindependent solution may not exist in such cases. In addition, the bubble dimension is not fully considered in the standard EulerEuler model.
In the present study, a particlecenteraveraging method is used to represent the bubble forces as forces that act on the bubbles' centers of mass. A particlecenteraveraged EulerEuler approach for bubbly flow simulations is developed by combining the particlecenteraveraged EulerEuler framework with a Gaussian convolution method. The convolution method is used to convert the phaseaveraged and the particlecenteraveraged quantities. The test results illustrate that the particlecenteraveraging method alleviates the overprediction of the gas volume fraction peak in the channel center and provides a meshindependent solution. In the particlecenteraveraged EulerEuler model, the bubble dimension is fully considered and bubble deformation can be considered by using anisotropic diffusion in quantities conversion.
Keywords: CFD; bubbly flow; EulerEuler

Lecture (Conference)
International Conference on Numerical Methods in Multiphase Flows 4, 28.30.09.2022, Venice, Italy
Permalink: https://www.hzdr.de/publications/Publ35488
Publ.Id: 35488