Simulations of bubble-wall collision and rebound
Research by Sohrab Towfighi, UAA/URA
Summer 2013
Abstract
The collision of a rising bubble with a solid upper wall is studied numerically using a phase-field
model for the interface in an axisymmetric geometry. Prior experiments show that the bubble
bounces off the wall if its incoming velocity is sufficiently high, and be- comes arrested
otherwise. Using experimental parameters, our computation reproduces the regimes of arrest
and rebound. We further investigate the critical condition delineating arrest from rebound and
the scaling of the coefficient of restitution. In agreement with prior work, we find that the
approach velocity of the bubble exhibits self-similarity and, when properly scaled, depends only
on the Bond number. Moreover, the critical conditions separating arrest and rebound can be
expressed by a threshold in the Reynolds number. In disagreement with earlier results, the
coefficient of restitution follows a capillary number scaling. We propose an empirical
correlation and explore the cause of the disagreement.