Bubbles in a viscous liquid : lattice Boltzmann simulation and experimental validation
Résumé
The dynamics of a single bubble rising in a viscous Newtonian fluid was investigated both experimentally by a particle image velocimetry (PIV) device and numerically using the free-energy-based lattice Boltzmann (LB) model. The rise velocity, bubble shape and flow field were considered for various bubble volumes in axisymmetric flow conditions. Experimentally, the flow measurements by the PIV device revealed the wake increasing with the bubble volume. Such an evolution is linked to the deformation of bubble shape from spherical for small bubbles to flattened at the bottom for large bubbles