A literature review on mechanisms and models for the coalescence process of fluid particles

This paper presents a literature review on mechanisms and models for the coalescence process of fluid particles (bubbles and drops). For the mechanisms, five categories are summarized, namely, turbulence fluctuation, viscous shear stress, capture in turbulent eddies, buoyancy and wake interaction. Models for the collision frequency and coalescence efficiency of bubbles or drops in turbulent liquid are reviewed thoroughly. The development and limitation of the existing models are studied and possible improvements are proposed.