Highly accurate simulation of electrokinetic transport processes in nanopores

• Applicant: Dr.-Ing. Holger Marschall
• Subject Area: Chemical and Thermal Process Engineering ; Fluid Mechanics
• Term: since 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 509491635

Subproject B3 is dedicated to the detailed modelling and highly accurate simulation of ion transport processes in transient nanopores under an applied potential. Thus, there is a direct link to the guiding experiment Electrically Modulatable Nanopores. The scientific focus of B3 is on the development of adaptive and hybrid approaches, which are particularly suitable to bridge the typically very different spatial and temporal scales in these transport processes and to numerically adequately implement the usually strong coupling between transport mechanisms. The central aim is to develop numerical methods of high numerical and physical fidelity for ion transport to produce physically accurate solutions. This is of high relevance, since classical measures of numerical fidelity (accuracy, stability, consistency) are not sufficient to address how well the system physics is represented by a particular numerical method. In practice, this is a surreptitious and subtle problem, since such a failure rarely causes outright abort of simulations due to instabilities, i.e., it can potentially go unnoticed leading to physically incorrect but converged results. This project will contribute to advancing the field of numerical methods and address the growing need for physically accurate solutions of ion transport processes in complex systems such as in transient nanopores under an applied potential. In particular, we will devise a hybrid atomistic-continuum (HAC) approach so as to couple molecular dynamics (MD) and continuum solvers, respectively. This enables a detailed computational analysis of ion transport processes close to the pore walls, where MD is used. Such an approach is particularly useful to examine transient pore systems where pure MD would be computationally prohibitive. As for the continuum solver, we will aim to implement most recent model formulations using improved closures to take into account effects like the finite size and solvation of ions in electrolytes. Moreover, a central objective is to develop a numerical method of high fidelity which accounts for the significant coupling between transport processes by means of an implicit simultaneous solution approach.

• DFG Programme: Research Units
• Subproject of: FOR 5584: Transient Sieves