A general two-phase debris flow model
A general two-phase debris flow model
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DOI：
10.1029/2011jf002186
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发表时间：
2012-09
影响因子：
--
通讯作者：
S. Pudasaini
中科院分区：
文献类型：
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作者：
S. Pudasaini
本文提出了一个新的、广义的两相泥石流模型，它包含了许多基本的物理现象。该模型对固体应力采用莫尔-库仑塑性，流体应力采用固体-体积-分数-梯度增强的非牛顿粘性应力模型。广义界面动量传递包括粘性阻力、浮力和虚质量。提出了一种新的、广义的阻力力，它涵盖了类固体和类流体的贡献，可以应用于从线性到二次的阻力。固体和流体动量传递之间的强耦合导致相同时变形、混合和分离。包含非牛顿粘性应力在几个方面是重要的。固体体积分数的演化、平流和扩散起着重要的作用。该模型包含了三个创新的、全新的、占主导地位的物理方面（增强粘性应力、虚拟质量、广义阻力），构成了迄今为止最广义的两相流模型，并且可以再现大多数以前将单相和两相雪崩和泥石流作为特殊情况考虑的简单模型的结果。数值计算结果表明，该模型能较好地描述陆上两相泥石流、颗粒流和弥散流、泥沙输运以及海底泥石流及其相关现象的复杂动力学过程。
[1] This paper presents a new, generalized two-phase debris flow model that includes many essential physical phenomena. The model employs the Mohr-Coulomb plasticity for the solid stress, and the fluid stress is modeled as a solid-volume-fraction-gradient-enhanced non-Newtonian viscous stress. The generalized interfacial momentum transfer includes viscous drag, buoyancy, and virtual mass. A new, generalized drag force is proposed that covers both solid-like and fluid-like contributions, and can be applied to drag ranging from linear to quadratic. Strong coupling between the solid- and the fluid-momentum transfer leads to simultaneous deformation, mixing, and separation of the phases. Inclusion of the non-Newtonian viscous stresses is important in several aspects. The evolution, advection, and diffusion of the solid-volume fraction plays an important role. The model, which includes three innovative, fundamentally new, and dominant physical aspects (enhanced viscous stress, virtual mass, generalized drag) constitutes the most generalized two-phase flow model to date, and can reproduce results from most previous simple models that consider single- and two-phase avalanches and debris flows as special cases. Numerical results indicate that the model can adequately describe the complex dynamics of subaerial two-phase debris flows, particle-laden and dispersive flows, sediment transport, and submarine debris flows and associated phenomena.