Do you use Tecplot to calculate vorticity from the velocity field or do you calculate the vorticity from your code, and then visualize it from tecplot? The way deal.II visualizes gradients (or vorticity in this case) is the correct way it should be done, because it is visualized on an "element basis", ensuring that the real discontinuities in the fields are seen. Many other software will smoothen the discontinuous field by using some sort of averaging and then output these values at the nodes. This gives the illusion that the fields are continuous, when they are not in reality (the averaging introduces the continuity). Consequently, this really depends on the procedure you are using to visualize your other results.
On Saturday, 18 January 2020 19:03:01 UTC-5, David Eaton wrote: > > I just use tecplot directly visualize the results. The vorticity contour > from my simple code is continuous, and the results from deal.II is > discontinuous (without L2 projection). Is it possible that the direct > solver in Intel mkl did a similar projection step internally? > > ------------------------------ > *From:* Wolfgang Bangerth <bang...@colostate.edu <javascript:>> > *Sent:* Sunday, January 19, 2020, 12:49 AM > *To:* David Eaton; dea...@googlegroups.com <javascript:> > *Subject:* Re: [deal.II] discontinous contour over elements > > On 1/18/20 9:25 AM, David Eaton wrote: > > Thank you for your explanations. Basically I formed a weak form of the > PDE for > > one element and numerically integrate it at the Gaussian points based on > the > > interpolation from the local nodes. Subsequently, I assemble the weak > forms > > from all elements into a global system matrix based on a local-to-global > > mapping of the nodes. After applying the boundary conditions, I solve > this > > linear system using a linear solver in Intel mkl. > > Right -- that gives you the solution (u,p) of the problem. But then what > do > you do to visualize whatever it is that you find is/isn't discontinuous? > > Best > W. > > -- > ------------------------------------------------------------------------ > Wolfgang Bangerth email: bang...@colostate.edu > <javascript:> > 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/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. To view this discussion on the web visit https://groups.google.com/d/msgid/dealii/95374e76-952b-4b1e-83dc-e784c9c0f472%40googlegroups.com.
