Hi, I am trying to solve a pressure poisson eqn resulting from the NS eqn. How can I fixed the pressure at some nodes while solving the poisson eqn?
I tried to make the coefficient of the diagonal location of the node very big e.g. 1e100. I also use call KSPSetInitialGuessNonzero(ksp,PETSC_TRUE,ierr) and insert the original values as initial solution: do i=1,blk(1)%size_x do j=1,blk(1)%size_y call VecSetValue(xx,k,blk(1)%p(i,j),INSERT_VALUES,ierr) k=k+1 end do end do in my code. However, after solving the eqn, the value I got is 1e-16 or 0. So what have I done wrong? Thanks