I can not obtain correct results for 2D Lid Driven cavity problem.
Dear Nektar group: I am conducting numerical simulation for 2D lid driven cavity problem with Re=1000. Attachment please find my xml file. But i found the output results at monitor point is different from benchmark solution from open literature. I have changed the order from 20 to 40, the nothing changed. but the stream line pattern is the same with benchmark solution. what should i do further> Regards Your Sincerely Ding
Dear Ding, In what way does your measurement differ from the literature. Is the difference substantial? Could you provide a plot of the output showing the differences? One challenge in this problem is the inconsistent boundary conditions at the ends of the top wall. The values used at the top left and top right corners depends on the order of the boundary conditions. You could therefore swap the order of the boundary regions/conditions in the XML file and see if that improves your solution? Cheers, Chris On 22/08/16 06:15, 丁老师 wrote:
Dear Nektar group: I am conducting numerical simulation for 2D lid driven cavity problem with Re=1000. Attachment please find my xml file. But i found the output results at monitor point is different from benchmark solution from open literature. I have changed the order from 20 to 40, the nothing changed. but the stream line pattern is the same with benchmark solution. what should i do further>
Regards Your Sincerely Ding
_______________________________________________ Nektar-users mailing list Nektar-users@imperial.ac.uk https://mailman.ic.ac.uk/mailman/listinfo/nektar-users
-- Chris Cantwell Imperial College London South Kensington Campus London SW7 2AZ Email: c.cantwell@imperial.ac.uk www.imperial.ac.uk/people/c.cantwell
Hi all, Dear Ding It is funny because a few months ago I was like you. Actually, I made the cavity flow problem and I get the same results of Ghia 1982 (High-Re Solutions for Incompressible Flow Using the Navier-Stokes Equations and a Multigrid Method, U. GHIA, K. N. GHIA, AND C. T. SHIN), you can find enclose the comparative plots, dots are the data reported by Ghia and in continuous the nektar results. V on the central horizontal line [image: Inline images 2] U on the central vertical line. [image: Inline images 1] I look your file and I don't sure but I think you have to specify the fields to made the expansion, I mean <EXPANSIONS> <E COMPOSITE="C[0]" NUMMODES="40" TYPE="MODIFIED" FIELDS="u,v,p" /> </EXPANSIONS> Please tell me how it is going. Regards, On 22 August 2016 at 08:02, Chris Cantwell <c.cantwell@imperial.ac.uk> wrote:
Dear Ding,
In what way does your measurement differ from the literature. Is the difference substantial? Could you provide a plot of the output showing the differences?
One challenge in this problem is the inconsistent boundary conditions at the ends of the top wall. The values used at the top left and top right corners depends on the order of the boundary conditions. You could therefore swap the order of the boundary regions/conditions in the XML file and see if that improves your solution?
Cheers, Chris
On 22/08/16 06:15, 丁老师 wrote:
Dear Nektar group: I am conducting numerical simulation for 2D lid driven cavity problem with Re=1000. Attachment please find my xml file. But i found the output results at monitor point is different from benchmark solution from open literature. I have changed the order from 20 to 40, the nothing changed. but the stream line pattern is the same with benchmark solution. what should i do further>
Regards Your Sincerely Ding
_______________________________________________ Nektar-users mailing list Nektar-users@imperial.ac.uk https://mailman.ic.ac.uk/mailman/listinfo/nektar-users
-- Chris Cantwell Imperial College London South Kensington Campus London SW7 2AZ Email: c.cantwell@imperial.ac.uk www.imperial.ac.uk/people/c.cantwell
_______________________________________________ Nektar-users mailing list Nektar-users@imperial.ac.uk https://mailman.ic.ac.uk/mailman/listinfo/nektar-users
-- --- Manuel Felipe Mejía De Alba.
Dear friends: The mesh1 has 2*2 element , with an order of 40. The mesh 2 has 8*8 element, with an order 0f 10. I am using these meshes with same order for the simulation of lid driven cavity problem at Re=1000. Both system can give converged solutions with a time step of 0.001. But mesh1's results is different from the benchmark solution greatly. Could you please give me some suggestions about this phenomeno. Regards At 2016-08-22 21:02:26, "Chris Cantwell" <c.cantwell@imperial.ac.uk> wrote:
Dear Ding,
In what way does your measurement differ from the literature. Is the difference substantial? Could you provide a plot of the output showing the differences?
One challenge in this problem is the inconsistent boundary conditions at the ends of the top wall. The values used at the top left and top right corners depends on the order of the boundary conditions. You could therefore swap the order of the boundary regions/conditions in the XML file and see if that improves your solution?
Cheers, Chris
On 22/08/16 06:15, 丁老师 wrote:
Dear Nektar group: I am conducting numerical simulation for 2D lid driven cavity problem with Re=1000. Attachment please find my xml file. But i found the output results at monitor point is different from benchmark solution from open literature. I have changed the order from 20 to 40, the nothing changed. but the stream line pattern is the same with benchmark solution. what should i do further>
Regards Your Sincerely Ding
_______________________________________________ Nektar-users mailing list Nektar-users@imperial.ac.uk https://mailman.ic.ac.uk/mailman/listinfo/nektar-users
-- Chris Cantwell Imperial College London South Kensington Campus London SW7 2AZ Email: c.cantwell@imperial.ac.uk www.imperial.ac.uk/people/c.cantwell
_______________________________________________ Nektar-users mailing list Nektar-users@imperial.ac.uk https://mailman.ic.ac.uk/mailman/listinfo/nektar-users
participants (3)
-
Chris Cantwell
-
Manuel F. Mejía De Alba
-
丁老师