My inflow condition is uniform. This formulation and mesh is tested in a simple C++ code without library. The large mesh near the inflow does not give this problem. Yes. I am using C0 element. I did calculation using tecplot. However, the results from a my C++ code does not give this issue either. Just now, I check the formulation again. Although I use Q2Q1 Taylor-Hood element without any stabilization, these issues are still happening.
________________________________ From: [email protected] <[email protected]> on behalf of Praveen C <[email protected]> Sent: Monday, January 13, 2020 12:04 PM To: Deal. II Googlegroup <[email protected]> Subject: Re: [deal.II] discontinous contour over elements Is your inflow conditions uniform ? If not then large elements at inflow could introduce errors. If you compute vorticity as curl of velocity pointwise, then the vorticity would be discontinuous at element boundaries, since you are using only C0 elements for the velocity. If you are averaging the computed vorticity or obtaining vorticity by an L2 projection, then they would be continuous. Maybe your other codes are doing something like this ? Best praveen On 13-Jan-2020, at 9:12 AM, David Eaton <[email protected]<mailto:[email protected]>> wrote: (1) This stabilized formulation is tested and running in code without any issue. However, it seems that the velocity fileld near the inlet, the left of figure "entire_domain", has large disturbances. (2) In figure "zoom_in_1", there is no irregularity of the streamline. Furthermore, the calculated lift and drag matches with the literature. It seems that the irregularity of flow field near the inlet is caused by very large elements. However, this issue is not observed in another code. (3) The most weird issue to me is in figure "zoom_in_2". The contour of velocity, vorticity seems to be discontinuous to their neighboring elements. I believe I am using continuous Galerkin element and standard Gauss quadrature rule (4 Gauss integration points for 2D simulation). This issue does not appear in other codes using the same formation. Could anyone suggest a reason for this? -- 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]<mailto:[email protected]>. To view this discussion on the web visit https://groups.google.com/d/msgid/dealii/E1E13F63-7365-4328-9673-4073CDEED6CC%40gmail.com<https://groups.google.com/d/msgid/dealii/E1E13F63-7365-4328-9673-4073CDEED6CC%40gmail.com?utm_medium=email&utm_source=footer>. -- 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 on the web visit https://groups.google.com/d/msgid/dealii/SL2PR01MB25536AC37C6EFBBAA106913DC3350%40SL2PR01MB2553.apcprd01.prod.exchangelabs.com.
