Particle-Fluid Coupling Algorithm Considering Dynamic Fluid Mesh

doi:10.16183/j.cnki.jsjtu.2020.317

Abstract

Abstract:

It is generally difficult to consider the fluid dynamic boundary problem in the traditional particle-fluid coupling algorithm, causing calculation errors owing to the mismatching of the fluid-solid boundary and affecting the accuracy of the results in the modeling of large deformation issues. In view of this problem, the dynamic updating method of fluid mesh is introduced and Darcy’s seepage equation and the particle-fluid interaction equation in dynamic mesh are derived. Based on the discrete element commercial software PFC^2D, the particle-fluid coupling algorithm considering dynamic fluid mesh is developed. The proposed algorithm is applied to simulate the undrained shear biaxial test of saturated soil. The comparison result with the constant volume method verifies the effectiveness of the developed algorithm. Finally, the algorithm is used to simulate the undrained biaxial tests at different confining pressures. The law of the calculated results agrees well with that of the laboratory tests. By considering the problem of fluid dynamic boundary, the developed algorithm can obtain the fluid-solid boundary matching in the simulation of triaxial compression test and one-dimensional consolidation test or other cases in large deformations, which can help to improve the simulation accuracy and offer a theoretical reference for similar studies.

Key words: fluid-solid coupling, dynamic mesh, constant volume method, biaxial test

CLC Number:

TU411

HE Jinhui, LI Mingguang, CHEN Jinjian, XIA Xiaohe. Particle-Fluid Coupling Algorithm Considering Dynamic Fluid Mesh[J]. Journal of Shanghai Jiao Tong University, 2021, 55(6): 645-651.

Figures/Tables 11

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颗粒参数	取值	颗粒参数	取值
颗粒密度/(kg·m^-3)	2500	切向刚度/(MN·m^-1)	100
最小颗粒直径/mm	3.6	摩擦因数	0.5
最大颗粒直径/mm	5.58	渗透性系数/(μm·s^-1)	10
法向刚度/(MN·m^-1)	100	试样初始孔隙率	0.16