The use of numerical based multi-phase fluid flow simulation can significantly aid in the development of an effective remediation strategy for groundwater systems contaminated with Dense Non Aqueous Phase Liquid (DNAPL). Incorporating the lithological heterogeneities of the aquifer into the model domain is a crucial aspect in the development of robust numerical simulators. Previous research studies have attempted to incorporate lithological heterogeneities into the domain; however, most of these numerical simulators are based on Finite Volume Method (FVM) and Finite Difference Method (FDM) which have limited applicability in the field-scale aquifers. Finite Element Method (FEM) can be highly useful in developing the field-scale simulation of DNAPL infiltration due to its consistent accuracy on irregular study domain, and the availability of higher orders of basis functions. In this research work, FEM based model has been developed to simulate the DNAPL infiltration in a hypothetical field-scale aquifer. The model results demonstrate the effect of meso-scale heterogeneities, specifically clay lenses, on the migration and accumulation of Dense Non Aqueous Phase Liquid (DNAPL) within the aquifer. Furthermore, this research provides valuable insights for the development of an appropriate remediation strategy for a general contaminated aquifer.

翻译：基于数值方法的多相流体流动模拟可显著提升针对受重质非水相液体（DNAPL）污染的地下水系统制定有效修复策略的能力。将含水层岩性非均质性纳入模型域是开发稳健数值模拟器的关键要素。已有研究尝试将岩性非均质性引入模型域，但大多数数值模拟器基于有限体积法（FVM）和有限差分法（FDM），这些方法在场地尺度含水层中的应用具有局限性。有限元法（FEM）因其在非规则研究域中保持一致的精度以及高阶基函数的可用性，在开发场地尺度的DNAPL入渗模拟中极具应用价值。本研究开发了基于FEM的模型，以模拟假设场地尺度含水层中的DNAPL入渗过程。模型结果展示了中尺度非均质性（特别是黏土透镜体）对含水层内重质非水相液体（DNAPL）运移与累积的影响。此外，本研究为制定受污染含水层的有效修复策略提供了重要参考。