Dynamics of fiber-laden drops

拟议的项目重点研究含有细丝或纤维的液滴的不稳定行为，在这里称为纤维负载液滴。在这样的三元体系中，结构、毛细管和流体动力学都是相互交织的。到目前为止，绝大多数关于纤维液滴的研究都集中在固定构型上。然而，纤维液滴的不稳定行为却受到的关注要少得多。该项目基于实验和模拟之间的密切互动，将重点放在两个涉及纤维液滴的关键场景上。首先，将分析纤维液滴对固体表面的低能量冲击，目的是阐明液滴内部的纤维如何影响液滴的动力学，特别是液滴的反弹。其次，我们将研究在通道结点处纤维液滴的产生。这项最新研究的一个目标是建立一种控制良好的高通量工艺，使液滴中含有准确数量的纤维。在进行实验研究的同时，还将开发一种能够处理纤维液滴快速动力学的数值模型。该模型基于混合欧拉/拉格朗日描述，其中纤维由相互作用的球形珠链表示。对于这两个关键场景中的每一个，都将基于实验和模拟之间的密切交互来探索由问题的无量纲数跨越的参数空间中的动态制度。

The proposed project focuses on the unsteady behavior of drops containing filaments or fibers, here referred to as fiber-laden drops. In such ternary systems, structural, capillary, and fluid dynamics are all intertwined. Up to now, the vast majority of studies involving fiber-laden drops that have been conducted were focused on stationary configurations. The unsteady behavior of fiber-laden drops, however, has received much less attention. The project, based on a close interaction between experiments and simulations, will focus on two key scenarios involving fiber-laden drops. First, the low-energy impact of fiber-laden drops on a solid surface will be analyzed, with the goal to clarify how the fiber inside the drop influences the dynamics and especially the rebound of the drop. Second, the generation of fiber-laden drops at a channel junction will be studied. One goal of this last investigation will be to establish a well-controlled high-throughput process with drops containing a precise number of fibers. The experimental investigations will be accompanied by the development of a numerical model capable of handling the fast dynamics of fiber-laden drops. The model is based on a hybrid Eulerian/Lagrangian description, where a fiber is represented by a chain of interacting spherical beads. For each of the two key scenarios, the dynamic regimes in a parameter space spanned by the dimensionless numbers of the problem will be explored based on a close interaction between experiments and simulations.