[论文解读] Unified Mechanical Erosion Model for Multi-phase Mass Flows

Shiva P. Pudasaini|arXiv (Cornell University)|Sep 22, 2022

Landslides and related hazards被引用 16

一句话总结

本文通过在侵蚀界面引入相互作用应力，提出了一种新颖的、统一的多相泥流机械侵蚀模型，通过摩擦力、碰撞力和黏性应力实现固相与液相侵蚀速率的物理解耦计算。该模型将全面的侵蚀速度、净动量生成以及侵蚀引起的惯性效应整合进质量与动量平衡方程中，构建了一个机械上严谨、动态灵活的框架，克服了现有模型的局限性。

ABSTRACT

Erosion poses a great challenge in multi-phase mass flows as it drastically changes flow behavior and deposition pattern by dramatically increasing their masses, adversely affecting population and civil structures. There exists no mechanically-explained, unified multi-phase erosion model. We constitute a novel, unified and comprehensive mechanical erosion rates for solid and fluid phases and demonstrate their richness and urgency. This is achieved by seminally introducing interacting stresses across erosion-interface. Shear resistances from the bed against shear stresses from the landslide are based on consistent physical principles including frictional, collisional and viscous stresses. Proposed multi-phase interactive shear structures are mechanically superior and dynamically flexible. Total erosion rate is the sum of solid and fluid erosion rates which are mechanically extensive and compact. Erosion rates consistently take solid and fluid fractions from the bed and customarily supply to solid and fluid components in the flow. This overcomes severe limitations inherited by existing models. For the first time, we physically correctly construct composite, intricate erosion velocities of particle and fluid from the bed and architect the complete net momentum productions that include all interactions between solids and fluids in the landslide and bed. We invent stress correction, erosive-shear-velocity, super-erosion-drift and erosion-matrix characterizing erosion processes. By embedding well constrained extensive erosion velocities, unified erosion rates and net momentum productions including erosion-induced inertia into mass and momentum balances, we develop a novel, mechanically-explained, comprehensive multi-phase model for erosive mass flows. The new model offers great opportunities for practitioners in solving technical, engineering problems related to erosive multi-phase mass flows.

研究动机与目标

• 解决多相泥流中缺乏机械一致性的统一侵蚀模型的问题。
• 克服现有侵蚀模型未能考虑流体与床层相之间相互作用应力的局限性。
• 构建一个基于物理原理的框架，通过一致的应力机制同时捕捉固相与液相的侵蚀速率。
• 通过嵌入侵蚀引起的惯性和动量生成，实现对质量流行为与沉积模式的精确预测。
• 提供一个全面、机械上严谨的模型，适用于工程与地球物理灾害评估。

提出的方法

• 基于摩擦力、碰撞力和黏性应力原理，在滑坡流与床层之间的侵蚀界面引入相互作用应力。
• 将统一的侵蚀速率表述为固相与液相侵蚀速率之和，每一项均基于一致的物理机制推导得出。
• 根据界面处的机械相互作用，定义颗粒与流体的复合侵蚀速度。
• 构建完整的净动量生成项，涵盖所有固-液相互作用及流体-床层相互作用。
• 将广泛的侵蚀速度与侵蚀引起的惯性效应嵌入质量与动量守恒方程中。
• 通过将所有组成部分整合进单一、机械一致的框架，构建全面的多相模型。

实验结果

研究问题

• RQ1 如何构建一个能同时考虑固相与液相的多相泥流统一机械侵蚀模型？
• RQ2 相互作用应力（摩擦力、碰撞力和黏性应力）在决定流体-床层界面侵蚀速率中起什么作用？
• RQ3 如何从侵蚀界面出发，物理解耦且一致地推导出颗粒与流体的侵蚀速度？
• RQ4 净动量生成（包括侵蚀引起的惯性）对侵蚀性泥流整体动力学的贡献是什么？
• RQ5 所提出的模型如何克服现有侵蚀模型在机械与动力学方面的局限性？

主要发现

• 该模型通过在侵蚀界面结合摩擦力、碰撞力和黏性应力，提出了一套物理解耦的侵蚀速率计算框架。
• 侵蚀速率被定义为固相与液相贡献之和，每一项均基于独立但一致的机械原理。
• 颗粒与流体的复合侵蚀速度由流体与床层应力的相互作用构建，实现了精确的动量传递。
• 净动量生成项得到完整考虑，包括侵蚀引起的惯性，确保了动力学一致性。
• 通过将所有相互作用嵌入质量与动量平衡方程，该模型展现出机械优越性与动态灵活性。
• 统一的公式化方法通过实现物理正确的、全面的多相流侵蚀动力学，克服了先前模型的严重局限性。