This work studies the collision of fluid particles (bubbles or droplets) in non-Newtonian media whose viscosity obeys the power-law model, by analyzing the behavior of the drainage of the film between the particles. The model considers a time-dependent collision velocity governed by a force balance over each particle, which renders the estimation of both coalescence and rebound possible and as a result the critical velocity separating the two regimes. Results indicate that the shear-thinning behavior of the continuous medium favors coalescence, whereas shear-thickening films promote rebound. The critical velocity increases with decreasing power-law index and follows an exponential trend with the equivalent particle size for a given value of the power-law index. The exponent showing the dependency of the critical velocity on the equivalent particle size changes linearly with the power-law index within the investigated parameter range. Both the drainage behavior and the critical velocity are shown to be affected only negligibly by the selection of the drag force closure, i.e., whether they are proposed by considering Newtonian or non-Newtonian media.

这项工作通过分析颗粒间薄膜的排水行为，研究粘度服从幂律模型的非牛顿介质中流体颗粒（气泡或液滴）的碰撞。该模型考虑了由每个粒子上的力平衡控制的与时间相关的碰撞速度，这使得可以估计聚结和反弹，从而得出分离两种状态的临界速度。结果表明，连续介质的剪切稀化行为有利于聚结，而剪切增稠膜则促进回弹。临界速度随着幂律指数的减小而增加，并且对于给定的幂律指数值，临界速度随等效颗粒尺寸呈指数趋势。显示临界速度对等效粒径的依赖性的指数在研究的参数范围内随幂律指数线性变化。排水行为和临界速度都显示仅受阻力闭合的选择的影响可以忽略不计，即，无论它们是通过考虑牛顿介质还是非牛顿介质提出的。