Advection dominated PDEsGradient discretisation methodEulerian Lagrangian Localised AdjointMethodModified Method of CharacteristicsMass conservationConvergence analysisLOCALIZED ADJOINT METHODMISCIBLE FLUID-FLOWSCONVERGENCE ANALYSISNUMERICAL-METHODSFINITE-ELEMENTPOROUS-MEDIAVOLUMEIMPLEMENTATIONAPPROXIMATIONDISPLACEMENT