Marc, On Thursday, December 7, 2017 at 11:52:39 AM UTC-5, Marc Fehling wrote:
> I stumbled over some interesting behavior of the heat equation from > step-26. If I reduce the time step to a smaller value, let's say to 1e-6, I > observe negative values for the solution near the sources (where gradients > are large), which I would not expect. I guess it is related to the > sharpness of the used right hand side function, since I could not observe > this behavior with a smooth Gaussian shaped one. So my idea was then that > DG methods may suppress this behavior. How are your thoughts about that? > This is a well-know problem and using DG won't solve it (unless you use DG_0, i.e., finite volume). You need some kind of flux limiter I don't know what works for your problem so you probably need to check the literature. <https://en.wikipedia.org/wiki/Flux_limiter> <https://en.wikipedia.org/wiki/Flux_limiter> Best, <https://en.wikipedia.org/wiki/Flux_limiter> <https://en.wikipedia.org/wiki/Flux_limiter> Bruno <https://en.wikipedia.org/wiki/Flux_limiter> <https://en.wikipedia.org/wiki/Flux_limiter> -- 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 [email protected]. For more options, visit https://groups.google.com/d/optout.
