Understanding the physics of droplet collisions is of crucial importance in many industrial processes such as inkjet printing, spray cooling, and spray combustion. In this paper, a modified multiple-relaxation-time pseudopotential multiphase lattice Boltzmann model is proposed to investigate binary droplet collision with different collision angles. The surface tension can be adjusted independently under the condition of high Reynolds number and large density ratio using this model. Then the model validation is performed by simulating three benchmark cases including stationary droplet, oscillating droplet, and capillary wave instability, respectively. Finally, different regimes of binary droplet collision are presented, and collision features such as liquid filament and satellite droplet are investigated at collision angles of 30°, 60°, 90°, 120°, and 150°. The results show that there is no liquid filament or satellite droplet at the collision angle of 30°, yet both of them appear as the angle increases. When the collision angle is 60°, the percentage of satellite droplet to liquid phase reaches 30%, while the proportions are less than 10% at collision angles of 90°, 120°, and 150°. Besides, two break-up mechanisms of “end-pinching” and capillary wave instability are inspected. It is found out that the back-flow phenomena at the joints of droplets and the liquid filament are caused by the “end-pinching” mechanism, which further leads to the capillary wave instability of the liquid filament.

在许多工业过程（例如喷墨打印，喷雾冷却和喷雾燃烧）中，了解液滴碰撞的物理原理至关重要。本文提出了一种改进的多重弛豫时间伪势多相晶格玻尔兹曼模型，研究了不同碰撞角度下的二元液滴碰撞。使用该模型，可以在高雷诺数和大密度比的条件下独立调节表面张力。然后，通过模拟三种基准情况分别进行模型验证，包括固定液滴，振荡液滴和毛细管波不稳定性。最后，介绍了不同的二元液滴碰撞方式，并研究了在30°，60°，90°，120°的碰撞角度下液体丝和卫星液滴等碰撞特征，和150°。结果表明，在30°的碰撞角处没有液态细丝或卫星液滴，但随着角度的增加它们都出现。当碰撞角度为60°时，卫星液滴相对于液相的百分比达到30％，而在90°，120°和150°的碰撞角度下，该比例小于10％。此外，还考察了“末端夹住”和毛细波不稳定性的两种破裂机理。发现在液滴与液体细丝的接头处的回流现象是由“端部夹紧”机制引起的，这进一步导致了液体细丝的毛细波不稳定性。卫星液滴相对于液相的百分比达到30％，而在90°，120°和150°的碰撞角下，该比例小于10％。此外，还考察了“末端夹住”和毛细波不稳定性的两种破裂机理。发现在液滴与液体细丝的接头处的回流现象是由“端部夹紧”机制引起的，这进一步导致了液体细丝的毛细波不稳定性。卫星液滴相对于液相的百分比达到30％，而在90°，120°和150°的碰撞角下，该比例小于10％。此外，还考察了“末端夹住”和毛细波不稳定性的两种破裂机理。发现在液滴与液体细丝的接头处的回流现象是由“端部夹紧”机制引起的，这进一步导致了液体细丝的毛细波不稳定性。