  Results of direct numerical simulations and laboratory experiments have been
used in order to show that the buoyancy driven bubbly flows at high gas volume
fraction are mixed by deterministic chaos with typical exponential spectrum of
the liquid kinetic energy, whereas at moderate and small gas volume fraction it
is a distributed chaos (turbulence or pseudo-turbulence) dominated by the third
and second moments of helicity distribution with the stretched exponential
spectra of the kinetic energy. Interaction of the bubbles with isotropic
(behind an active grid) and near-wall turbulent flows has been also discussed
from this point of view with an application to the pressurized water nuclear
reactors.
