Application of Smoothed Particle Hydrodynamics (SPH) for the Simulation of Flow-like Landslides on 3D Terrains

Flow-type landslide is one type of landslide that generally exhibits characteristics of high flow velocities, long jump distances, and poor predictability. Simulation of it facilitates propagation analysis and provides solutions for risk assessment and mitigation design. The smoothed particle hydrodynamics (SPH) method has been successfully applied to the simulation of two-dimensional (2D) and three-dimensional (3D) flow-like landslides. However, the influence of boundary resistance on the whole process of landslide failure is rarely discussed. In this study, a boundary algorithm considering the friction is proposed, and integrated into the boundary condition of the SPH method, and its accuracy is verified. Moreover, the Navier-Stokes equation combined with the non-Newtonian fluid rheology model was utilized to solve the dynamic behavior of the flow-like landslide. To verify its performance, the Shuicheng landslide event, which occurred in Guizhou, China, was taken as a case study. In the 2D simulation, a sensitivity analysis was conducted, and the results showed that the shearing strength parameters have more influence on the computation accuracy in comparison with the coefficient of viscosity. Afterwards, the dynamic characteristics of the landslide, such as the velocity and the impact area, were analyzed in the 3D simulation. The simulation results are in good agreement with the field investigations. The simulation results demonstrate that the SPH method performs well in reproducing the landslide process, and facilitates the analysis of landslide characteristics as well as the affected areas, which provides a scientific basis for conducting the risk assessment and disaster mitigation design.

A Review of SPH Techniques for Hydrodynamic Simulations of Ocean Energy Devices

This article is dedicated to providing a detailed review concerning the SPH-based hydrodynamic simulations for ocean energy devices (OEDs). Attention is particularly focused on three topics that are tightly related to the concerning field, covering (1) SPH-based numerical fluid tanks, (2) multi-physics SPH techniques towards simulating OEDs, and finally (3) computational efficiency and capacity. In addition, the striking challenges of the SPH method with respect to simulating OEDs are elaborated, and the future prospects of the SPH method for the concerning topics are also provided.

An Improved Dynamic Boundary Condition in SPH Method

Dynamic boundary condition (DBC) has been widely used in SPH method. However, in certain situations, it was found that a few fluid particles could break through the boundary or were not reflected specularly. Of course, these phenomena are unphysical. To improve the performance of DBC, an improved dynamic boundary condition (IDBC) was presented in this paper. To prevent fluid particles from breaking through the boundary, the repulsive force of boundary particles was enhanced by expanding the equation of state into a higher order. To deal with the asymmetry of DBC, a rectangular support domain attached to boundary particles and a corresponding correction factor are proposed. The results of three test cases showed that the performance of IDBC was satisfied.

A Novel Improved Coupled Dynamic Solid Boundary Treatment for 2D Fluid Sloshing Simulation

In order to achieve stable and accurate sloshing simulations with complex geometries using Smoothed Particle Hydrodynamic (SPH) method, a novel improved coupled dynamic solid boundary treatment (SBT) is proposed in this study. Comparing with the previous SBT algorithms, the new SBT algorithm not only can reduce numerical dissipation, but also can greatly improve the ability to prevent fluid particles penetration and to expand the application to model unidirectional deformable boundary. Besides the new SBT algorithm, a number of modified algorithms for correcting density field and position shifting are applied to the new SPH scheme for improving numerical stability and minimizing numerical dissipation in sloshing simulations. Numerical results for three sloshing cases in tanks with different geometries are investigated in this study. In the analysis of the wave elevation and the pressure on the tank, the SPH simulation with the new SBT algorithm shows a good agreement with the experiment and the simulations using the commercial code STAR-CCM+. Especially, the sloshing case in the tank with deformable bottom demonstrates the robustness of the new boundary method.