Plume spreading in groundwater by stretching and folding

Stretching Folding Instablility and Nanoemulsion

Stretching and folding in finite time.

Complex flows mix efficiently, and this process can be understood by considering the stretching and folding of material volumes. Although many metrics have been devised to characterize stretching, fewer are able to capture folding in a quantitative way in spatiotemporally variable flows. Here, we extend our previous methods based on the finite-time curving of fluid-element trajectories to nonze...

Separating stretching from folding in fluid mixing

Fluid mixing controls many natural and industrial processes, including the spread of air pollution1, mass transfer and reactions in microfluidic devices2,3 and the detection of odours or other chemical signals4. Strongly nonlinear flows enhance mixing by chaotic advection5,6, stretching and folding7,8 fluid volumes. Though these processes have been studied in simple models9,10, stretching and f...

Numerical stochastic analysis of groundwater contaminant transport and plume containment

Firstand second-order reliability methods (FORM and SORM) are applied as alternatives to the Monte Carlo simulation method in the probabilistic analysis of groundwater contaminant transport and remediation. A two-dimensional finite-element model is interfaced with a reliability analysis program to account for uncertainty in aquifer media. Hydraulic conductivity is modeled as a spatial random fi...

Groundwater-surface water interaction and its role on TCE groundwater plume attenuation.

A field investigation of a TCE plume in a surficial sand aquifer shows that groundwater-surface water interactions strongly influence apparent plume attenuation. At the site, a former industrial facility in Connecticut, depth-discrete monitoring along three cross-sections (transects) perpendicular to groundwater flow shows a persistent VOC plume extending 700 m from the DNAPL source zone to a m...