Hi Ed, Having a quick look at your file it seems the problem might be something like a temperature driven flow in a box? Adding a temperature field like this might be the issue since I would have expected this case to run otherwise. Mohammad (cc’ed) has been working on a branch of the code where we have fixed a number of issues to do with adding a temperature field. @Mohammad: Could you try running Ed’s case and see if it works for you? If so I suggest Ed runs on your branch until we get that merged? Cheers, Spencer. Spencer Sherwin FREng, FRAeS Head of Aerodynamics Section, Director of Research Computing Service, Professor of Computational Fluid Mechanics, Department of Aeronautics, South Kensington Campus, Imperial College London, SW7 2AZ, UK Phone: +44 (0)20 7594 5052 http://www.imperial.ac.uk/people/s.sherwin/ On 10 Sep 2020, at 18:04, Edward Threlfall <ejthrelfall@gmail.com<mailto:ejthrelfall@gmail.com>> wrote: This email from ejthrelfall@gmail.com<mailto:ejthrelfall@gmail.com> originates from outside Imperial. Do not click on links and attachments unless you recognise the sender. If you trust the sender, add them to your safe senders list<https://spam.ic.ac.uk/SpamConsole/Senders.aspx> to disable email stamping for this address. Dear users, I have been running simulations of 3D convection in a box with the incompressible Navier-Stokes solver. I find that there is always an anomaly at one of the points, where the pressure field is zero (it is obvious that this zero value is wrong - see attached image). It might be worth noting that in the image, there are 12 elements with 4 modes per direction each, so 12*4^3 (=768) degrees of freedom, and the anomalous point seems to be number 767 i.e. the final one, so perhaps the last pressure variable is not being updated. The session file used to generate the result shown in the image is attached (takes about 1min to run on my laptop). Also note it is correct that u, v, w, and T are zero at the sample point - just not p! I have found this issue on a variety of cuboidal and also tetrahedral meshes. The command to run I used is mpiexec -np 4 incnavierstokessolver nektar_3d_convection.xml Can anyone help resolve this? Many thanks, Dr Ed Threlfall, UKAEA. <nektar_3d_convection_problem.png><nektar_3d_convection.xml>_______________________________________________ Nektar-users mailing list Nektar-users@imperial.ac.uk<mailto:Nektar-users@imperial.ac.uk> https://mailman.ic.ac.uk/mailman/listinfo/nektar-users [cid:2f4f14e6-b17f-4bec-bf8d-4ed6c4304a82@eurprd06.prod.outlook.com]
