A coupling model for bubble coalescence considering the effect of the collision‐induced surface deformation

Abstract Most of the existing coalescence models could not reasonably account for the effect of bubble surface deformation. This work develops an improved model by coupling the approach and liquid film drainage processes, which consider both the initial and collision‐induced deformations. The surface deformation degree is characterized by a surface restoring force. Besides, this model reveals that both the curvature and the ratio of major to minor axes evolve with time. This model is introduced into the coalescence frequency that includes six turbulent eddy collision mechanisms and the population balance equation. The whole energy spectrum with bottleneck effect is also considered. The results predicted by the model show good agreement with the experimental data of aspect ratios (ranging from 1.1 to 1.4), events of coalescence and rebound, critical coalescence velocity (in the range of 0.02–0.2 m/s) and bubble size distribution.