Coupled DEM-CFD analyses of landslide-induced debris flows

• Main Author: Zhao, Tao
• Format: Electronic eBook
• Language: English
• Published: Singapore : Springer, [2017]
• Subjects: Debris avalanches.; elektronické knihy; electronic books
• ISBN: 9789811046278; 9789811046261
• Physical Description: 1 online resource : illustrations

This book reflects the latest research results in computer modelling of landslide-induced debris flows. The book establishes an understanding of the initiation and propagation mechanisms of landslides by means of numerical simulations, so that mitigation strategies to reduce the long-term losses fro...

Table of Contents:

• Preface; Acknowledgements; Contents; Nomenclature; 1 Introduction to Landslides; 1.1 Background; 1.2 Terrestrial Landslides; 1.2.1 Classification and Characteristics; 1.2.2 Major Research on Terrestrial Landslides; 1.3 Submerged Landslides; 1.3.1 Classification and Characteristics; 1.3.2 Major Research on Submerged Landslides; 1.4 Model Testing-Granular Column Collapse; 1.5 Numerical Investigations; 1.5.1 The Finite Element Method; 1.5.2 The Smoothed Particle Hydrodynamics; 1.5.3 The Discrete Element Method; 1.5.4 The DEM-CFD Coupling Method; 2 Introduction to Discrete Element Method.
• 2.1 The Discrete Element Method2.1.1 Particle Motion; 2.1.2 The Particle-Particle Contact Model; 2.1.3 The Calculation of Stress in the DEM; 2.1.4 Coordination Number; 2.2 Model Validation; 2.2.1 Input Parameters of the DEM Model; 2.2.2 Determination of Numerical Time Step; 2.2.3 Numerical Simulation of Triaxial Tests; 2.2.3.1 Model Configuration; 2.2.3.2 Results; 2.2.4 Material Angle of Repose; 2.2.4.1 Results; 2.3 Conclusions; 3 Investigation of Dry Granular Flows; 3.1 The Granular Column Collapse Model; 3.2 Dimensional Analysis; 3.3 Numerical Simulations.
• 3.3.1 Deformation of the Granular Assembly3.3.2 Influence of Initial Column Aspect Ratio; 3.3.3 Influence of Model Size Ratio; 3.3.4 Influence of Column Characteristic Strain; 3.3.5 Influence of Material Internal Friction Angle; 3.4 Mechanical Analyses; 3.4.1 Evolution of Granular Velocity; 3.4.2 Granular Energy; 3.4.3 Linear Momentum; 3.4.4 Flux of Kinetic Energy; 3.4.5 Distribution of Kinetic Energy and Linear Momentum; 3.4.6 Evolution of Force Chains; 3.4.7 Distribution of Stress; 3.4.8 Distribution of Coordination Number; 3.4.9 Destination of Surface Grains.
• 3.4.10 Influence of Air Viscous Force3.5 Conclusions; 4 Introduction to the DEM-CFD Coupling Model; 4.1 Fluid-Solid Interaction; 4.2 Governing Equations of Fluid Flow; 4.2.1 Fluid Mass Conservation Law; 4.2.2 Fluid Momentum Conservation Law; 4.3 The Viscous Shear Stress; 4.3.1 Laminar Flow Regime; 4.3.2 Turbulent Flow Regime; 4.3.3 Near-Wall Treatment; 4.3.4 Initial Conditions; 4.4 The MPI Implementation and Data Exchange; 4.5 Fluid Flow Through a Porous Soil Sample; 4.5.1 Analytical Solution of Soil Permeability; 4.5.2 Numerical Model Configuration; 4.5.3 Laminar Flow; 4.5.4 Turbulent Flow.
• 4.6 Numerical Investigation of Granular Sedimentation4.6.1 The Settling of a Single Particle; 4.6.2 Batch Granular Sedimentation; 4.6.2.1 Segregation of Grains; 4.6.2.2 Density Profile of the Suspension; 4.6.2.3 Excess Pore Water Pressure and Effective Stress; 4.6.2.4 Energy of Solid Grains in the System; 4.6.2.5 Force Chain of the Sediments; 4.7 Conclusions; 5 Investigation of Submerged Debris Flows; 5.1 Model Configuration; 5.2 Physical Properties of Sediments; 5.3 Dimensional Analysis; 5.3.1 Discussion of the Dimensionless Groups; 5.3.2 Summary of the Dimensionless Groups.