thank you for your response, Prof. Wolfgang Bangerth.
In Step-24, I encountered numerical dispersion in my wave equation simulations at the beginning. I understand that this issue can often be mitigated by refining the mesh and reducing the time step. However, in the results of Step-89, even with a relatively coarse mesh, the numerical dispersion seems much smaller. It also appears that higher-order interpolation is applied, which is more in line with my expectations. What I would like to understand is why Step-89 gives better results than Step-24. As mentioned earlier, in Step-24, the results appear to resemble linear interpolation, even though I used third-order finite elements. In contrast, Step-89 seems to produce results that behave more like higher-order interpolation. Additionally, I’ve noticed that the parameters of the `build_patches` function seem to have a significant impact on the output, which might explain some of the differences. If my question is still unclear or confusing, I completely understand and I appreciate your time. Please feel free to ignore it if it’s not clear. I can reduce the time step as much as possible to minimize numerical dispersion. 在2024年11月30日星期六 UTC+8 23:48:02<Wolfgang Bangerth> 写道： > On 11/29/24 22:10, meng deng wrote: > > I trid the same initial value in step-24 as step-89, but step-89 is > smoother > > than step-24, and step-89 needs less grids. I also set the fe.degree -> > 3. > > Meng, > can you explain in more detail what it is you tried, and how the result > you > get differs from your expectation? I have to admit that I do not > understand > from your message (or the follow-up) what it is you ask about. > > Best > WB > -- 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]. To view this discussion visit https://groups.google.com/d/msgid/dealii/9f08af2f-e799-41b9-81ab-dff5c1519053n%40googlegroups.com.
