泥石流能量传递机制与耦合数学模拟

项目名称： 泥石流能量传递机制与耦合数学模拟

项目编号： No.51279144

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 水利工程

项目作者： 曹志先

作者单位： 武汉大学

项目金额： 82万元

中文摘要： 泥石流是一类典型的非恒定水沙流动，涉及极其复杂的水沙相互作用，并可能与底部边界发生质量、动量和能量交换。然而，迄今对泥石流形成、演化和消退的物理机制的理解远没有完善，还缺少普遍适用的数学模拟理论以预报泥石流致灾过程。本项目将泥石流中水与细颗粒混合物视作粘性流体、将粗颗粒作为固相连续介质，充分考虑泥石流与可冲积底部边界之间的交换，从湍流运动模式理论和质量、动量、能量守恒律出发建立泥石流两相耦合动力学数学模拟理论；揭示泥石流形成、演化与消退过程中能量传递的行为、规律与物理机制，特别是粗颗粒脉动动能、平均运动动能及其与流体相湍流能量产生与耗散之间的关系，进而建立泥石流自增强机制发生的临界条件。该项研究将发展泥石流运动的基础理论，增进对泥石流物理机制的理解，并为泥石流灾害的防御提供新的数值模拟技术。

中文关键词： 泥石流；两相流；泥沙运动；泥石流效率；能量传递

英文摘要： Debris flows are typical unsteady water-sediment flows, involve highly complicated interactions between water and sediment, and may feature substantial mass, momentum and energy exchanges with the bottom boundaries. However, current understanding of the mechanism of the generation, development and recession of debris flows remains far from complete, and generally applicable mathematical models for debris flows are still missing. This project sets out to develop a two-phase coupled modelling theory for debris flows based on mass, momentum and energy conservations laws, in which the mixture of water and sufficiently fine sediments is considered as quasi-fluid phase, and coarse sediments is regarded as "solid" phase, and the interactions between debris flows and erodible bottom boundary are properly incorporated. It also aims to unravel how energy is transferred in debris flows, especially the relationships between the fluctuation and mean energy components of the solid phase of coarse sediments, the counterparts of the fluid phase and energy dissipation. The threshold conditions for the occurrence of self-reinforcement of debris flows will also be established. The project will contribute to the progress of the fundamental theory and enhanced understanding of the physical mechanism of debris flows, and therefore fa

英文关键词： debris flow；two-phase flow；sediment transport；debris flow efficiency；energy transfer