论文标题
与粘性流体中的落球与接触:将数值模拟与实验数据进行比较
Falling balls in a viscous fluid with contact: Comparing numerical simulations with experimental data
论文作者
论文摘要
我们评估了针对物理实验数据的流体结构(接触)相互作用问题的许多不同有限元方法。为此,我们从Hagemeier [Mendeley Data,doi:10.17632/MF27C92NC3.1]中获取数据。这包括掉入高粘性流体的单个颗粒的轨迹,并从底部流体罐壁上反弹。所得流量是蠕变和湍流之间的过渡状态。由于流体结构域的发生较大变化以及壁与粒子之间的接触,这种类型的配置对于数值方法尤其具有挑战性。在数值模拟中,我们考虑了掉落颗粒的刚性体和线性弹性模型。在第一种情况下,我们比较了建立的任意拉格朗日欧拉(ALE)方法和移动域cutfem方法的结果,以及一种简单而常见的方法,以避免接触率。对于与接触的完整流体结构相互作用(FSI)问题,我们使用Nitsche方法的统一FSI接触治疗结合使用了完全欧拉的方法。为了提高计算效率,我们使用实验设置的几何对称性将FSI系统重新制定为两个空间维度。最后,我们显示了完整的三维啤酒计算,以研究粒子初始状态下的小扰动的影响,以研究实验中观察到的完全垂直跌落的偏差。这些方法是在开源有限元库中实现的,结果可自由使用可重现性。
We evaluate a number of different finite element approaches for fluid-structure (contact) interaction problems against data from physical experiments. For this we take the data from experiments by Hagemeier [Mendeley Data, doi: 10.17632/mf27c92nc3.1]. This consists of trajectories of single particles falling through a highly viscous fluid and rebounding off the bottom fluid tank wall. The resulting flow is in the transitional regime between creeping and turbulent flows. This type of configuration is particularly challenging for numerical methods due to the large change of the fluid domain and the contact between the wall and particle. In the numerical simulations we consider both rigid body and linear elasticity models for the falling particles. In the first case, we compare results obtained with the well established Arbitrary Lagrangian Eulerian (ALE) approach and a moving domain CutFEM method together with a simple and common approach for contact avoidance. For the full fluid-structure interaction (FSI) problem with contact, we use a fully Eulerian approach in combination with a unified FSI-contact treatment using Nitsche's method. For higher computational efficiency we use the geometrical symmetry of the experimental set up to reformulate the FSI system into two spatial dimensions. Finally, we show full three dimensional ALE computations to study the effects of small perturbations in the initial state of the particle to investigate deviations from a perfectly vertical fall observed in the experiment. The methods are implemented in open-source finite element libraries and the results are made freely available to aide reproducibility.