The electroneutrality constraint in nonlocal models
Abstract
We develop a nonlocal Nernst-Planck model for reaction and diffusion in multicomponent ionic systems. We apply the model to the one-dimensional liquid junction problem, in which two electrolytic solutions of different ionic concentrations are brought into contact via a permeable membrane. Transport of ions through the membrane induces an electric field which is modeled using two separate nonlocal conditions: charge conservation and Gauss’ law. We investigate how well they satisfy the criterion of strict electroneutrality which stipulates that the net charge at each point in the domain is zero, by considering four different initial scenarios. Charge conservation and Gauss’ law yield similar results for most practical scenarios in which the initial condition satisfies strict electroneutrality. However, Gauss’ law has two important advantages over charge conservation: (i) it is numerically more stable and can be applied even when the concentration of all the charged species drops to zero and (ii) computationally, it is significantly cheaper. Further, this study provides insights on the prescription of electroneutrality conditions necessary to handle the physics of evolving charges in nonlocal peridynamic models that are aimed at modeling nonlocal reaction-diffusion or corrosion-type processes.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Sep 25, 2017
- Source ID
- 10.1063/1.5003915
Entities
People
- Eitan Lees
- Max Gunzburger
- Sachin Shanbhag
- Srujan Rokkam
Organizations
- Florida State University
- Naval Air Systems Command