Dear all,
I want to develop a code to solve the partial differential equation in
two dimensions (dim=2). The unknown functions in this equation are c1
(concentration for solute 1), c2 (concentration for solute 2), psi
(potential) and u (displacement). The coupling between these vaiables
are :
c1 ---- psi (equation for solute 1)
c2 ---- psi (equation for solute 2)
psi----c1---- c2----u (equation for psi)
u ----c1---- c2----psi (equation for displacement u)
Here we assume that these equations are linear. c1, c2, psi and are
each component of u approximated by Q1 element (there are dim=2
components in the displacement). The system matrix is the following
4*4 block matrix
c1 c2 psi u
------------------
c1 | * 0 * 0
c2 | 0 * * 0
psi| * * * *
u | * * * *
Here 0 are the zero matrix, and * presents the matrix we want to
assemble. My question is how to give the finite elment system? I use
FESystem<dim> fe;
fe (FE_Q<dim>(degree), 1,
FE_Q<dim>(degree), 1,
FE_Q<dim>(degree), 1,
FE_Q<dim>(degree), dim)
It is wrong because it is not supported by deal ii. If I use, for example,
fe (FE_Q<dim>(degree), 2,
FE_Q<dim>(degree), 1,
FE_Q<dim>(degree), dim)
It cannot produce the 4*4 block matrix. What should I do?
Thanks
Daming Li
_______________________________________________
dealii mailing list http://poisson.dealii.org/mailman/listinfo/dealii
