A numerical framework for bubble transport in a subcooled fluid flow
Journal article, 2017

In this paper we present a framework for the simulation of dispersed bubbly two-phase flows, with the specific aim of describing vapor–liquid systems with condensation. We formulate and implement a framework that consists of a population balance equation (PBE) for the bubble size distribution and an Eulerian–Eulerian two-fluid solver. The PBE is discretized using the Direct Quadrature Method of Moments (DQMOM) in which we include the condensation of the bubbles as an internal phase space convection. We investigate the robustness of the DQMOM formulation and the numerical issues arising from the rapid shrinkage of the vapor bubbles. In contrast to a PBE method based on the multiple-size-group (MUSIG) method, the DQMOM formulation allows us to compute a distribution with dynamic bubble sizes. Such a property is advantageous to capture the wide range of bubble sizes associated with the condensation process. Furthermore, we compare the computational performance of the DQMOM-based framework with the MUSIG method. The results demonstrate that DQMOM is able to retrieve the bubble size distribution with a good numerical precision in only a small fraction of the computational time required by MUSIG. For the two-fluid solver, we examine the implementation of the mass, momentum and enthalpy conservation equations in relation to the coupling to the PBE. In particular, we propose a formulation of the pressure and liquid continuity equations, that was shown to correctly preserve mass when computing the vapor fraction with DQMOM. In addition, the conservation of enthalpy was also proven. Therefore a consistent overall framework that couples the PBE and two-fluid solvers is achieved.

Two-fluid

Direct quadrature method of moments

PBE

Condensation

CFD

Author

Klas Jareteg

Chalmers, Physics, Subatomic and Plasma Physics

Srdjan Sasic

Chalmers, Applied Mechanics

Paolo Vinai

Chalmers, Physics, Subatomic and Plasma Physics

Christophe Demaziere

Chalmers, Physics, Subatomic and Plasma Physics

Journal of Computational Physics

0021-9991 (ISSN) 1090-2716 (eISSN)

Vol. 345 373-403

Infrastructure

C3SE (Chalmers Centre for Computational Science and Engineering)

Subject Categories

Fluid Mechanics and Acoustics

DOI

10.1016/j.jcp.2017.05.033

More information

Created

10/7/2017