Solving Discretized Multivariables System of ODEs

3 views (last 30 days)
Hi all,
I am solving PDEs of drift-difussion ion exchange (Nernst Plank equations) as shown in the attached picture (equation (1) and there are two more for B and D species). The dependent variables that I want temporally to solve are the concentration of A, B and D. I have discretized the generic equations using finite volume method for all three species and ended up with long equations ( eq(2) and eq(3) for A and B. As you notice, I have reduced some terms in order to simplify it and make it easier to read. Also, I have not included discretized formula of D since they are all the same). Anyway, I have six boundary conditons (two for each species) and initial conditions at t=0 for all. That is, all rhd terms are known at t=0 when solving for C at t=t+dt.
So my questions are:
1- Which ODE solver should I use? ODE45 and ODE15 solve IVP and bvp4c or bvp5c solve BVPs, but I have both conditions.
2- Each solver that I mentioned in the previous question tend to obtain the solution for just one spatial node, how can I make it work for the whole spatial domain?
3- The discretized ODEs I have are uncoupled since each term in rhs are known from perivous time step. From my poor knowledge, most of ODE solvers accept the coupled ones, so can I still use them? correct me if I am wrong.

Answers (1)

Amit Bhowmick
Amit Bhowmick on 3 Jul 2021
use pdepe
Amit Bhowmick
Amit Bhowmick on 5 Jul 2021
Some lines are missing in the code. Not running

Sign in to comment.




Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by