A Multi‐Phase Mass Flow Model
A Multi‐Phase Mass Flow Model
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DOI：
10.1029/2019jf005204
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发表时间：
2019-12
期刊：
影响因子：
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通讯作者：
S. Pudasaini;M. Mergili
中科院分区：
文献类型：
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作者：
S. Pudasaini;M. Mergili
地貌质量流的物质成分及其在空间和时间上的演化通常很复杂。这些危险现象的模拟将极大地受益于多相模型，考虑到运动和重要的是以不同物理方面为特征的相的相互作用，包括密度、摩擦、粘度、分数及其机械响应。然而，这样一个真正的多相模型仍然缺乏。在这里，我们提出了第一个由三个不同相组成的多机械、多相质量流模型：粗固体部分、细固体部分和粘性流体。粗糙的固体成分称为固体，代表巨石、鹅卵石、砾石或冰块。细固体代表细颗粒和沙子，而水和非常细的颗粒，包括胶体、淤泥和粘土，构成混合物中的粘性流体成分。所涉及的材料表现出独特的机械响应和动态行为。因此，固相、细固相和液相由库仑塑性、剪切和压力相关的塑性主导的粘塑性和粘度主导的粘塑性流变学来描述。它们应该最能代表这些材料。新模型非常灵活，解决了多相质量流的一些长期存在的问题，即如何可靠地描述此类现象的流动动力学、跳动和沉积形态。结合一些基准模拟，讨论了模型的本质及其适用性。
Geomorphic mass flows are often complex in terms of material composition and its evolution in space and time. The simulation of those hazardous phenomena would strongly benefit from a multi‐phase model, considering the motion and—importantly—interaction of phases characterized by different physical aspects including densities, frictions, viscosities, fractions, and their mechanical responses. However, such a genuine multi‐phase model is still lacking. Here, we present a first‐ever, multi‐mechanical, multi‐phase mass flow model composed of three different phases: the coarse solid fraction, fine‐solid fraction, and viscous fluid. The coarse solid component, called solid, represents boulders, cobbles, gravels, or blocks of ice. Fine‐solid represents fine particles and sand, whereas water and very fine particles, including colloids, silt, and clay, constitute the viscous fluid component in the mixture. The involved materials display distinct mechanical responses and dynamic behaviors. Therefore, the solid, fine‐solid, and fluid phases are described by Coulomb‐plastic, shear‐ and pressure‐dependent plasticity‐dominated viscoplastic, and viscosity‐dominated viscoplastic rheologies. They are supposed to best represent those materials. The new model is flexible and addresses some long‐standing issues of multi‐phase mass flows on how to reliably describe the flow dynamics, runout, and deposition morphology of such type of phenomena. With reference to some benchmark simulations, the essence of the model and its applicability are discussed.