Physics of Fluids Group, Faculty of Science and Technology, MESA+ Institutes, Burgers Center for Fluid Dynamics, University of Twente, 7500AE Enschede, The Netherlands.
Phys Rev Lett. 2013 Jun 28;110(26):264503. doi: 10.1103/PhysRevLett.110.264503.
The impact of a drop onto a deep bath of an immiscible liquid is studied with emphasis on the drop fragmentation into a collection of noncoalescing daughter drops. At impact the drop flattens and spreads at the surface of the crater it transiently opens in the bath and reaches a maximum deformation, which gets larger with increasing impact velocity, before surface tension drives its recession. This recession can promote the fragmentation by two different mechanisms: At moderate impact velocity, the drop recession converges to the axis of symmetry to form a jet which then fragments by a Plateau-Rayleigh mechanism. At higher velocity the edge of the receding drop destabilizes and shapes into radial ligaments which subsequently fragment. For this latter mechanism the number N∝We3 and the size distribution of the daughter drops p(d)∝d-4 as a function of the impact Weber number We are explained on the basis of the observed spreading of the drop. The universality of this model for the fragmentation of receding liquid sheets might be relevant for other configurations.
研究了不可混溶液体深浴中的液滴冲击，重点是液滴碎裂成一系列不聚并的子液滴。在冲击时，液滴在浴坑中暂态打开的表面变平并扩展，到达最大变形，随着冲击速度的增加而增大，然后表面张力使其后退。这种后退可以通过两种不同的机制促进碎裂：在中等冲击速度下，液滴后退收敛到对称轴形成射流，然后通过 Plateau-Rayleigh 机制碎裂。在更高的速度下，后退液滴的边缘失稳并形成径向韧带，随后碎裂。对于后一种机制，子液滴的数量 N∝We3，且子液滴的尺寸分布 p(d)∝d-4，这与冲击韦伯数 We 有关，这是基于观察到的液滴扩展。对于后退液膜碎裂的这种模型的普遍性可能与其他配置有关。
