Gas-liquid foams are important in applications ranging from oil recovery and mineral flotation to food science and microfluidics. Beyond their practical use, they represent an intriguing prototype of a soft material with a complex, viscoelastic rheological response. Crucially, foams allow detailed access to fluid-dynamical processes on the mesoscale of bubbles underlying the large-scale material behavior. This review emphasizes the importance of the geometry and interaction of mesoscale structural elements for the description of the dynamics of entire foams. Using examples including bulk flow of foam under steady shear, interfacial instabilities, and foam fracture through bubble rupture, this article highlights the wide variety of available theoretical descriptions, ranging from network modeling approaches coupling structural element equations of motion to full continuum models with elastoviscoplastic constitutive relations. Foams offer the opportunity to develop rigorous links between such disparate descriptions, providing a blueprint for physical modeling of dynamical multiscale systems with complex structure.

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气液泡沫动力学：从结构单元到连续体描述


气液泡沫在从石油开采和矿物浮选到食品科学和微流体学的各种应用中都非常重要。除了实际用途之外，它们还代表了具有复杂粘弹性流变响应的软材料的有趣原型。至关重要的是，泡沫允许详细访问大规模材料行为基础的气泡中尺度上的流体动力学过程。这篇综述强调了中尺度结构元件的几何形状和相互作用对于描述整个泡沫动力学的重要性。本文使用包括稳态剪切下的泡沫整体流动、界面不稳定性和气泡破裂导致的泡沫破裂在内的示例，重点介绍了各种可用的理论描述，从耦合结构单元运动方程的网络建模方法到具有弹塑性本构关系的全连续体模型。泡沫提供了在这种不同的描述之间建立严格联系的机会，为具有复杂结构的动态多尺度系统的物理建模提供了蓝图。