Mingjun Pang*, Zhan Zhang, Yang Fei and Yidan Xu Pages 193 - 201 ( 9 )
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 stress model.
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.
Bubbly flow, liquid turbulence modulation, gravity, bubble coalescence, mixture model, bubble velocity.
School of Mechanical Engineering, Changzhou University, Changzhou, School of Mechanical Engineering, Changzhou University, Changzhou, School of Mechanical Engineering, Changzhou University, Changzhou, School of Mechanical Engineering, Changzhou University, Changzhou