题目：Simulating Fluid-Solid Interaction Using Smoothed Particle Hydrodynamics Method

报告时间：2017年8月18号（周五）上午10点

报告地点：慧园6栋311会议室

报告人：潘凯（Massachusetts Institute of Technology）

摘要

This work is focused on developing a general numerical modeling framework based on Smoothed Particle Hydrodynamics (SPH) method to model the coupled problem, with application to wave impact on floating offshore structures, and the hydraulic fracturing of rocks induced by fluid pressure.

The work first explores a weakly compressible SPH method to simulate the wave impact on rigid-body floating structures. Following validation, this framework is applied to simulation of the impact of large waves on an offshore structure. A new numerical technique is proposed for generating multi-modal and multi-directional sea waves with SPH. The waves are generated by moving the side boundaries of the fluid domain according to the sum of Fourier modes, each with its own direction, amplitude and wave frequency. The method is used to simulate two different extreme wave events, with generally good agreement between the simulated waves and the recorded real-life data.

The second application is the modeling of hydro-fracture initiation and propagation in rocks. A new general SPH numerical coupling method is developed to model the interaction between fluids and solids, which includes non-linear deformation and dynamic fracture initiation and propagation. A Grady-Kipp damage model and a Drucker-Prager plasticity model are employed to model the tensile and shear failure of the solid. A new stress coupling approach and a corrected form of density computation are proposed to maintain the stress continuity and handle the density discontinuity at the fluid-solid interface. The method is validated against analytic solutions for a hydrostatic problem and for a pressurized borehole problem. The simulation of hydro-fracture initiation and propagation in the presence of in-situ stresses is also presented. Good results demonstrate that SPH has the potential to accurately simulate the hydraulic-fracturing phenomenon in rocks.

个人简历

潘凯博士在中国科学技术大学近代物理专业取得理学学士学位，之后就读于美国麻省理工学院（MIT）取得物理学硕士和土木和计算工程学博士学位，现任MIT博士后讲师。在麻省理工学院就读期间，师从John Williams教授；主要从事工程流体力学力学和固体力学数值模拟方面的研究。已发表及录用SCI源刊论文15篇，第一作者3篇，Nature子刊第二作者一篇，在审SCI论文2篇。在国际会议上作学术报告10余次。博士在读期间负责两项与跨国公司合作课题：数值模拟巨浪对石油钻井平台和离岸建筑物的冲击（壳牌石油公司）以及数值模拟水力压裂技术在开采页岩油技术上的应用（法国道达尔石油公司）。受邀作为2个国际知名期刊审稿人《Rock Mechanics and Rock Engineering》和《Journal of Computational Particle Method》。申请人研究主要集中在多尺度复杂物理系统中的流体和固体耦合问题，无网格数值模拟方法以及大规模计算机并行计算技术。在学术界上第一次应用光滑粒子方法(SPH method)成功模拟了极端海浪对海洋离岸建筑物的冲击情况，以及第一次成功用该方法耦合高压水和页岩的相互作用，用以深入研究和改进水力压裂技术。申请人的科研成果在海洋工程，建筑机构工程和油气开发工程等领域都有着重要的应用前景，也对新型的海洋离岸建筑的设计以及新型水力压裂技术在油气开采中的应用提供了一定的指导意义。