Background: Bubbly flows can frequently be seen in engineering fields such as fermentation
reactions, floatation of minerals, drag reduction by bubbles, etc. The physical parameters often change
in industrial processes, so it is important to conduct extensive studies on the influence of gas- and liquid-
phase parameters on the liquid turbulence.
Objective: The extensive studies are performed on the liquid turbulence modulation by bubble injection
with change of bubble velocity, gravity magnitude and considering bubble coalescence, and some physical
laws on liquid turbulence flow laden with bubbles are applied to guide the design of patents on the
drag reduction system by bubbles.
Methods: The bubbly turbulent flows are investigated with the numerical method, the mixture model is
chosen as the multiphase flow model, and the velocity field of the turbulent flow is solved by Reynolds
Results: The present results show that the bubble velocity has the very little influence on the liquidphase
turbulence; the gravity magnitude has the definite influence on the liquid-phase turbulence, and
the influence of the bubble injection on the liquid-phase turbulence under normal gravity is far greater
than that under microgravity. In addition, only when the bubble volume fraction is sufficiently high, the
bubble coalescence has the significant influence on the liquid-phase turbulence.
Conclusion: The influence of gravity on the bubble distribution and the liquid-phase turbulence is important,
and the bubble coalescence causes the definite influence on the liquid turbulence modulation
when the bubble volume fraction is high enough.