Dynamics of fiber-laden drops

该项目的重点是包含细丝或纤维的液滴的不稳定行为，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相互交织。 到目前为止，绝大多数涉及纤维负载液滴的研究都集中在固定构型上。然而，含纤维液滴的非稳态行为却很少受到关注。该项目基于实验和模拟之间的密切互动，将重点关注两个关键场景，涉及纤维负载液滴。首先，将分析固体表面上负载纤维的液滴的低能量冲击，目的是澄清液滴内的纤维如何影响动态，特别是液滴的回弹。第二，将研究在通道连接处的纤维负载液滴的产生。最后一项研究的一个目标是建立一个控制良好的高通量过程，其中液滴含有精确数量的纤维。实验研究将伴随着一个数值模型的发展，能够处理的快速动态的纤维负载液滴。该模型是基于一个混合欧拉/拉格朗日描述，其中的纤维是由一个链的相互作用的球形珠。对于两个关键的场景，在参数空间中的动态政权跨越的无量纲数的问题将探索实验和模拟之间的密切互动的基础上。

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.