Abstract The collision of two fluid particles with similar sizes approaching each other with time dependent velocities is studied in this work via a film drainage model that can render both coalescence and rebound. The model equations are simplified following the lubrication theory and the interfaces are treated as deformable ones. The particle velocities are governed by a force balance that includes the added mass, the drag, the buoyancy and the film forces. The film force stems from the pressure build up within the film due to interfacial deformations, and its presence in the model enables the particles to bounce, provided that the film becomes resistant enough for the surface energy stored during the approach of the particles to convert back to kinetic energy. The simulations result in rebound when the collision energy is high, in coalescence when the energy is in an intermediate range, and in particles reaching a steady-state for even lower energies. The critical velocity value, at which the rebound regime starts, is found to be similar to the experimental ones in the literature, and presented as a function of key model parameters.

中文翻译：

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关于流体颗粒聚结和回弹的预测：薄膜排水研究

摘要 在这项工作中，通过可以呈现聚结和回弹的薄膜排水模型，研究了大小相似的两种流体粒子以时间相关的速度相互碰撞。根据润滑理论对模型方程进行了简化，并将界面视为可变形界面。粒子速度受力平衡控制，包括附加质量、阻力、浮力和薄膜力。薄膜力源于由于界面变形而在薄膜内形成的压力，并且它在模型中的存在使粒子能够弹跳，前提是薄膜具有足够的抵抗力，以便在粒子接近期间存储的表面能转换回来为动能。当碰撞能量高时，模拟导致反弹，在能量处于中间范围时的聚结，以及在更低能量下达到稳态的粒子。发现反弹状态开始时的临界速度值与文献中的实验值相似，并表示为关键模型参数的函数。