库岸滑坡涌浪CFD-FEM-DEM流固耦合数值模拟方法与机理研究

库岸滑坡涌浪是亟待解决的重大工程问题，但现有方法依赖于过多的简化和假定，无法准确反映离散滑坡体与库水、空气间复杂的相互作用及能量交换的本质特征。本项目拟提出可变形离散元流固耦合分析理论，构建CFD-FEM-DEM流固耦合并行数值模拟方法，结合物理试验及已发生的实际滑坡涌浪问题，验证耦合方法的准确性，基于数值方法模拟库岸边坡变形、启动、破坏与滑动及涌浪产生过程。通过建立有限元-距离势离散元耦合方法，研究滑坡运动过程中的变形、碰撞和破碎等连续-非连续变化过程。在此基础上，着力突破离散运动介质的大运动流固耦合问题，并采用有效的界面捕捉方法描述涌浪波剧烈变化现象，提出解决离散介质入水耦合问题的CFD-FEM-DEM流固耦合数值模拟方法，实现库岸边坡滑坡涌浪多相介质连续-非连续流固耦合数值仿真。将所提方法应用于具体工程，研究各相介质之间的能量传递规律，挖掘涌浪产生机理，预测库岸边坡滑坡涌浪灾害。

The landslide movement and the generated impulse waves in reservoirs are issues of importance, while the present methods rely on oversimplifications and hypotheses. Hence, the complex and drastic interaction and the energy exchange among the discontinuous landslides, the water and the air cannot be reflected exactly. A theory about the coupling between the fluid and the deformable discontinuous landslides will be proposed in this project. Moreover, a numerical method of CFD-FEM-DEM fluid-solid coupling will also be presented. The accuracy of the proposed method will be verified by comparing the simulation results with the outcomes of physical experiments and field data of practical engineering projects. Afterwards, the CFD-FEM-DEM method will be employed to simulate the deformation, activation, fracture, movement of landslides and the generation of impulse waves. The change from continuous to discontinuous of landslides, including fracture and crash, will be studied by the coupled method of the finite element method (FEM) and the distance-potential discrete element method (DEM). On the basis, the CFD-FEM-DEM fluid-solid coupling method will also be proposed by solving the interaction between the discontinuous landslides with large movement and the fluid and capturing the interfaces which undergo dramatic deformation, including rolling, separating and merging. The CFD-FEM-DEM fluid-solid coupling method can be employed to simulate the whole process of the landslide movement and the generation of the impulse wave with high accuracy. The proposed method can be applied to model practical engineering projects, study the energy exchange among the three phases, reveal the mechanism of the landslide movement and the generation of the impulse wave and predict the potential disaster.