Dispersive mixing dynamics of dense miscible plumes: natural perturbation initiation by local-scale heterogeneities

摘要

Two-dimensional, coupled variable-density flow and transport simulations with heterogeneous media advance understanding of how local-scale non-idealities creats and control instabilities. Dense plumes(5000 mg 1~-1 NaCl)are introduced into a domain(1.50×0.56 m)with syntheti- Cally generated permeability fields. Simulations with the first set of realizations[mean permeabil- Ity(k)=5.7×10~-11 m~2, ln(k) variance = 0.25, longitudinal correlation length(τ_x)=0.10 m, Transverse correlation length(τ_z)=0.02 m]illustrate how the lower plume boundary is naturally Perturbed by local-scale heterogeneties.