Water transport mechanisms during pressure-driven transport through polyamide nanogaps.

Molecular-scale simulations of pressure-driven transport through polyamide nanogaps (5-100 Å) were performed to investigate fundamental transport mechanisms. Results show that transport in nanogaps  10 Å is always subdiffusive, but superdiffusive transport was observed in nanogaps  20 Å. Near typical operating pressures for applications (  = 100 atm), only the 100 Å nanogap exhibited superdiffusive behavior.

A scalable convolutional neural network approach to fluid flow prediction in complex environments.

We evaluate the capability of convolutional neural networks (CNNs) to predict a velocity field as it relates to fluid flow around various arrangements of obstacles within a two-dimensional, rectangular channel. We base our network architecture on a gated residual U-Net template and train it on velocity fields generated from computational fluid dynamics (CFD) simulations. We then assess the extent to which our model can accurately and efficiently predict steady flows in terms of velocity fields associated with inlet speeds and obstacle configurations not included in our training set.

Molecular Methods for Assessing the Morphology, Topology, and Performance of Polyamide Membranes.

The molecular-scale morphology and topology of polyamide composite membranes determine the performance characteristics of these materials. However, molecular-scale simulations are computationally expensive and morphological and topological characterization of molecular structures are not well developed. Molecular dynamics simulation and analysis methods for the polymerization, hydration, and quantification of polyamide membrane structures were developed and compared to elucidate efficient approaches for producing and analyzing the polyamide structure.

Microscale modeling of nondilute flow and transport in porous medium systems.

Nondilute transport occurs routinely in porous medium systems. Experimental observations have revealed effects that seemingly depend upon density, viscosity, velocity, and chemical activity. Macroscale models based upon averaged behavior over many pores have been relied upon to describe such systems to date, which require parametrization of important physical phenomena in material coefficients.