Global existence of a strong solution to the initial value problem for the Nernst-Planck-Navier-Stokes system in high space dimensions
Xiangsheng Xu
TL;DR
The paper proves the global existence of a strong solution to the initial-value NPNS system in $\mathbb{R}^N$ for $N\ge 3$ with any number of ionic species. The approach hinges on a novel scaling of the dependent variables combined with a De Giorgi iteration, yielding a uniform $L^{\infty}$ bound for $w=\sum_i c_i$ that is independent of the time horizon. This key estimate enables Calderón–Zygmund regularity for the electric potential $\phi$ and bootstraps to bounded velocity $u$, allowing the local strong solution to be extended globally. The method extends previous results for the two-species case to arbitrary $I$, providing a robust framework for global regularity of the NPNS system on unbounded domains. The results solidify the connection between weak and strong solutions and have implications for modeling ion transport in electrokinetic fluids.
Abstract
We study the existence of a strong solution to the initial value problem for the Nernst-Planck-Navier-Stokes (NPNS) system in $\mathbb{R}^N, N\geq 3$. The system describes the electrodiffusion of ions in a viscous Newtonian fluid. A strong solution is obtained in any dimension of space without constraints on the number of species or the size of the given data.
