I am trying to solve a system of 3 PDE's and I know that two of the equations have very different time scales. Hence, when I use NDSolve, I am getting an error that suggests that a stiff system is suspected. Does anyone know what can be done to solve a system of PDE's with different time scales?
The code also is taking a very long time to run since an increased step size helps the code run for longer before I get the stiff error. Is there a good combination of options that will give me an accurate result but not take so long to compute?
I have attached a copy of my code so you can see what I am talking about, if it helps. The r[t,x] equation solves fine by itself, but the c[t,x] and v[t,x] equations are what is giving me trouble.
Attachment: Retina Model4.nb, URL: ,