论文标题

富集的Galerkin离散化,用于建模异质多孔培养基的孔隙弹性和渗透率改变

Enriched Galerkin Discretization for Modeling Poroelasticity and Permeability Alteration in Heterogeneous Porous Media

论文作者

Kadeethum, T., Nick, H. M., Lee, S., Ballarin, F.

论文摘要

在多孔培养基中的耦合流体流量和固体变形的准确模拟是具有挑战性的,尤其是当培养基的渗透性和增生性是异质的时。我们将富集的Galerkin(EG)有限元方法应用于Biot系统。说明了用于构成富集空间和线性化和用于解决耦合介质通透性改变的迭代方案的块结构。提出了用于构建块结构的开源平台,并说明它有助于富集的Galerkin方法易于适应任何现有的不连续的Galerkin代码。随后,我们将EG方法与经典的连续Galerkin(CG)和不连续的Galerkin(DG)有限元方法进行了比较。尽管这些方法为Terzaghi的一维巩固的压力溶液提供了相似的近似值,但CG方法在具有渗透性对比的材料界面上产生了流体压力和体积应变溶液中的虚假振荡,并且不能局部巩固质量。结果,CG方法的通量近似与EG和DG方法之一,尤其是对于软材料而言。 EG和DG方法之间通量近似的差异无关。尽管如此,EG方法的自由度比DG方法分别需要大约两次和三维几何形状的自由度。最后,我们说明即使对于更粗的网格,EG方法也会产生准确的结果。

Accurate simulation of the coupled fluid flow and solid deformation in porous media is challenging, especially when the media permeability and storativity are heterogeneous. We apply the enriched Galerkin (EG) finite element method for the Biot's system. Block structure used to compose the enriched space and linearization and iterative schemes employed to solve the coupled media permeability alteration are illustrated. The open-source platform used to build the block structure is presented and illustrate that it helps the enriched Galerkin method easily adaptable to any existing discontinuous Galerkin codes. Subsequently, we compare the EG method with the classic continuous Galerkin (CG) and discontinuous Galerkin (DG) finite element methods. While these methods provide similar approximations for the pressure solution of Terzaghi's one-dimensional consolidation, the CG method produces spurious oscillations in fluid pressure and volumetric strain solutions at material interfaces that have permeability contrast and does not conserve mass locally. As a result, the flux approximation of the CG method is significantly different from the one of EG and DG methods, especially for the soft materials. The difference of flux approximation between EG and DG methods is insignificant; still, the EG method demands approximately two and three times fewer degrees of freedom than the DG method for two- and three-dimensional geometries, respectively. Lastly, we illustrate that the EG method produces accurate results even for much coarser meshes.

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