基于计算流体力学-离散元法耦合方法的海底黏性滑坡体运动行为模拟  

Numerical simulation on the movement behavior of viscous submarine landslide based on coupled computational fluid dynamics-discrete element method

作　　者：年廷凯[1] 张放 郑德凤[2] 李东阳 沈月强 雷得浴 NIAN Ting-kai;ZHANG Fang;ZHENG De-feng;LI Dong-yang;SHEN Yue-qiang;LEI De-yu(State Key Laboratory of Coastal and Ofshore Engineering,Dalian University of Technology,Dalian,Liaoning 116024,China;Liaoning Key Laboratory of Physical Geography and Gcomatics,Liaoning Normal University,Dalian,Liaoning 116029,China)

机构地区：[1]大连理工大学海岸和近海工程国家重点实验室,辽宁大连116024 [2]辽宁师范大学自然地理与空间信息科学重点实验室,辽宁大连116029

出　　处：《岩土力学》2022年第11期3174-3184,共11页Rock and Soil Mechanics

基　　金：国家自然科学基金项目(No.42077272,No.51879036,No.52079020);辽宁省兴辽英才计划项目(No.XLYC2002036)。

摘　　要：海底滑坡是海洋中常见的一种灾害地质现象,一旦发生将会对水下基础设施造成破坏,而目前很少有有关海底黏性滑坡体运动演化行为方面的模拟研究。采用计算流体动力学(computational fluid dynamics,简称CFD)和离散元法(discrete element method,简称DEM)建立了描述水与颗粒相互作用的流固耦合模型,通过引入颗粒间黏聚力模型,发展海底黏性滑体运动演化过程的CFD-DEM耦合分析方法,并开展了多个典型算例的验证分析。在此基础上,考虑滑体黏性作用和初始速度,系统地模拟了海底滑坡体的运动学特征(运动速度和距离)和形态特征(滑体长度、宽度、形状等),并深入探究了滑体运动及演化过程的影响机制。结果表明:该耦合方法可以较好地模拟再现海底滑坡体的小尺度运动行为,滑坡体的黏性作用对其运动学特征和形态特征具有显著影响,初始速度也明显影响了滑体各部位在运动过程中的颗粒流场演化及分布特征。这一成果可为真实海底滑坡的运动演化过程模拟和有效预测提供重要的科学依据。Submarine landslide is one of the main marine geological disasters. Once submarine slide happens, it will cause serious damage to underwater infrastructures. However, there are few researches on the movement and evolution of submarine landslides,especially considering the viscous effect of submarine landslides. A fluid-structure coupling model describing the interaction between water and particles was established by using computational fluid dynamics(CFD) and discrete element method(DEM), and a cohesive force model was introduced to develop a coupled CFD-DEM analysis method considering the viscous characteristics of sliding body. On this basis, the kinematic characteristics(velocity and distance) and morphological characteristics(length, width,shape, etc.) of the submarine landslide were systematically simulated by considering the viscosity and initial velocity of the landslide,and the influencing mechanism of the evolution process of the landslide movement was investigated in depth. The results show that the coupled method can simulate and reproduce the small-scale movement behavior of the submarine landslide well, the viscous action of the landslide has a remarkable influence on its kinematic and morphological characteristics, and the initial velocity also significantly affects the evolution and distribution characteristics of the particle flow field in each part of the landslide. The results can provide a scientific basis for the evolution process simulation and the effective prediction of submarine landslides.

关 键 词：海底滑坡 CFD-DEM耦合 JKR黏聚力模型 滑体运动特征 黏性滑坡体 

分 类 号：TU443[建筑科学—岩土工程]