一种考虑流体状态方程的土体CFD-DEM耦合数值方法

发布时间：2018-01-25 14:14

本文关键词： CFD-DEM数值方法 Tait状态方程颗粒自由沉降一维单面排水固结　出处：《岩土工程学报》2014年05期 　论文类型：期刊论文

【摘要】：在离散元(DEM)商业软件PFC2D的基础上,通过将描述流体体变压力非线性关系的Tait状态方程(EOS)引入计算流体动力学(CFD),建立模拟弱可压缩流体的CFD-DEM耦合计算模块。首先,推导CFD-DEM的控制方程:包括流体颗粒相互作用力方程、流体运动方程、Tait状态方程和颗粒运动方程。接着,通过PFC2D自定义FISH语言和C++语言将离散化的CFD-DEM控制方程嵌入商业软件PFC2D中。最后,通过单颗粒水下自由沉降运动和一维单面排水固结试验的模拟验证该耦合模块的可行性。模拟结果表明单颗粒自由沉降速度和Stokes理论解接近,一维单面排水固结试验中孔压消散和固结度随着无因次时间因数Tv的变化均与太沙基固结理论符合较好。从而使得用离散元法全耦合分析土体不排水条件下的力学特性成为可能。
[Abstract]:On the basis of the commercial software PFC2D, the Tait equation of state (EOS), which describes the nonlinear relationship between variable pressure and pressure of fluid bodies, is introduced into the computational fluid dynamics (CFD). The CFD-DEM coupling calculation module is established to simulate the weak compressible fluid. Firstly, the governing equations of CFD-DEM are derived, including the fluid particle interaction force equation and the fluid motion equation. Tait equation of state and equation of motion of particles. Through the PFC2D custom FISH language and C language, the discrete CFD-DEM control equation is embedded in the commercial software PFC2D. Finally. The feasibility of the coupling module is verified by the simulation of single particle free settlement under water and one-dimensional single-side drainage consolidation test. The simulation results show that the free settlement velocity of single particle is close to that of Stokes theory. The variation of pore pressure dissipation and consolidation degree along with dimensionless time factor T _ v in one-dimensional single-side drainage consolidation test is in good agreement with Terzaghi consolidation theory, so that the discrete element method is used to analyze the soil mass under undrained conditions. Mechanical properties are possible.
【作者单位】：同济大学土木学院地下建筑与工程系;岩土及地下工程教育部重点实验室(同济大学);西澳大利亚大学海洋基础系统中心;
【基金】：国家杰出青年科学基金项目(51025932) 教育部博士点基金项目(20100072110048)
【分类号】：TU43
【正文快照】： 0引言一般而言,自然界的土是一个多相物质。例如,饱和土是液体、固体两相的;非饱和土是液体、气体和固体三相的。只有在极少数情况下可将土体视为单相的,如干砂。液体、气体属于流体范畴,而岩土工程问题中的土颗粒大多数情况下运动速度较小因而属于固体范畴。因此,在岩土工程

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