Genetic Exponentially Fitted Method for Solving Multi-dimensional Drift-diffusion Equations

A general approach was proposed in this article to develop high-order exponentially fitted basis functions for finite element approximations of multi-dimensional drift-diffusion equations for modeling biomolecular electrodiffusion processes. Such methods are highly desirable for achieving numerical stability and efficiency. We found that by utilizing the one-one correspondence between continuous piecewise polynomial space of degree $k+1$ and the divergence-free vector space of degree $k$, one can construct high-order 2-D exponentially fitted basis functions that are strictly interpolative at a selected node set but are discontinuous on edges in general, spanning nonconforming finite element spaces. First order convergence was proved for the methods constructed from divergence-free Raviart-Thomas space $RT_0^0$ at two different node set

Electrodiffusion on the surface of bilayer membranes

2012 Spring.Includes bibliographical references.The cell memebrane is of utmost importance in the transportation of nutrients to the cell which are needed for survival. The magnitude of this is the inspiration for our study of the lipid bilayer which forms the cell membrane. In this paper we present a continuum model of electrodiffusion of lipids on the surface of bilayer membranes. Offering three derivations of the surface electrodiffusion equation, and proofs for the existence and uniqueness of the solution. A method for calculating integration constants using slotboom variables is emloyed. The development of a linear surface finite element method to solve the surface electrodiffusion equation is presented. Numerical simulations implementing the model are also given. The stability of the model is analyzed and a stability scheme using Streamline Upwind Petrov-Galerkin equations is applied. We test our code for robustness using other examples and a complex mesh. The implementation is validated by comparing with the known solution for the equations