Dear Prof. Bangerth, Thank you very much for your reply. I got your points.
Regards, Anup. On Wed, Nov 30, 2016 at 4:29 PM, Wolfgang Bangerth <bange...@colostate.edu> wrote: > On 11/30/2016 03:26 PM, Anup Basak wrote: > >> >> Let us consider an 1D domain with periodic BC applied on both ends. Then >> it is clear from your reply that the gradient terms have equal and >> opposite >> contribution in the weak form and they just vanish. In homogeneous Neumann >> BC also these terms do not participate. However, the difference is that >> with >> periodic >> BC they normal component of the gradients need not be zero. Hence my >> question is >> how this fact (i.e. non-zero value of normal component of gradient) is >> being >> ensured >> in the case when we are applying periodic BC. >> > > It's because in the periodic case, the periodicity is part of the function > space and is enforced via constraints through the ConstraintMatrix object. > This does not happen for homogenous Neumann conditions. > > > Also, in the periodic BC implementation of dealii is this part of the BC, >> i.e. >> equality >> (with -ve sign ) of normal component of the gradients are taken care of? >> > > It isn't. You only enforce that the *values* of the solution are equal. > The equality of the gradients (and consequently the negative equality of > the normal component) happens as a result. > > > Best > W. > > > -- > ------------------------------------------------------------------------ > Wolfgang Bangerth email: bange...@colostate.edu > www: http://www.math.colostate.edu/~bangerth/ > > -- > The deal.II project is located at http://www.dealii.org/ > For mailing list/forum options, see https://groups.google.com/d/fo > rum/dealii?hl=en > --- You received this message because you are subscribed to the Google > Groups "deal.II User Group" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to dealii+unsubscr...@googlegroups.com. > For more options, visit https://groups.google.com/d/optout. > -- The deal.II project is located at http://www.dealii.org/ For mailing list/forum options, see https://groups.google.com/d/forum/dealii?hl=en --- You received this message because you are subscribed to the Google Groups "deal.II User Group" group. To unsubscribe from this group and stop receiving emails from it, send an email to dealii+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
