Hi, I am trying to learn the tricks/methods of dealii by tweaking this program slightly. I was trying to solve step 31 with the following changes(Kindly bear with me if the questions are silly.)
1. Change Laplacian of velocity to just velocity in the stokes equation. For this, I changed 'grads_phi_u[i]' to 'phi_u[i]' and 'grads_phi_u[j]' to 'phi_u[j]' in 'local matrix' in 'assemble stokes system' and made similar changes in 'assemble stokes preconditioner' methods. I thought this was the only change that needs to be made since the weak form changes only in this term. But the program doesn't run for t>0 :( 2. I then tried to change the boundary conditions for temperature from Neumann to Dirichlet(as was mentioned in the website).I made a couple of weak attempts but I am not able to figure out if there is a straight forward way to do this. 3. As a side note, I was just checking the output of grad_phi_i_s in step 21 and this is always zero(at least for the first 30 time steps). Can someone tell me the reason for this? Thanks in advance. Seshu _______________________________________________ dealii mailing list http://poisson.dealii.org/mailman/listinfo/dealii
