Abstract
A numerical study of the isothermal migration of a two-dimensional bubble in Poiseuille flow is reported here for vapor-liquid density and dynamic viscosity ratios of 1/8, Red=1, and Ca=2. A lattice Boltzmann model with a van der Waals equation of state is employed to simulate the diffuse interface for three interface thickness to bubble diameter ratios, 1/5, 1/10, and 1/20. Point-by-point comparisons with the sharp-interface incompressible counterpart (reported in the literature) reveal velocity discrepancies which are more evident on the vapor side. These differences are a manifestation of a finite mass flux through the interface, associated with driven finite-thickness interfaces. An analytical study of the one-dimensional analog of the traveling diffuse interface problem explains this phenomenon and shows that this flux vanishes as a result of viscous dissipation as the interface thickness tends to zero. This trend is corroborated by the two-dimensional lattice Boltzmann results.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 817-825 |
| Number of pages | 9 |
| Journal | Physics of fluids |
| Volume | 13 |
| Issue number | 4 |
| DOIs | |
| State | Published - 2001 |
ASJC Scopus subject areas
- Computational Mechanics
- Condensed Matter Physics
- Mechanics of Materials
- Mechanical Engineering
- Fluid Flow and Transfer Processes