Hi Peter, You're right. I left the source term in the ini file because it may not evaluate to zero depending on the choice of the length scale in the Reynolds number (since the domain is not a unit square). When the length scale is chosen to be 1 ( Re = 1/nu) which is the case in all of our simulations so far, then the source term vanishes and that's what's used in the ini file attached. So I don't think that the source term is the cause of the problem. I removed it now just in case but I got the exact same results.
Regards, Mohamed Kamra On Wed, Oct 7, 2020 at 10:48 AM Vincent, Peter E <[email protected]> wrote: > Hi Mohamed, > > I am a little confused as to the test case you are using. > > The 2D TGV case in the paper you reference does not seem to use a method > of manufactured solutions, it just solves the regular NS equations without > a source term? > > Apologies if I missed something. > > Peter > > Professor of Computational Fluid Dynamics and EPSRC Fellow > Department of Aeronautics > Imperial College London > South Kensington > London > SW7 2AZ > UK > > > On 6 Oct 2020, at 16:38, Mohamed M. Kamra <[email protected]> > wrote: > > > Hi, > Thanks for the prompt response > I followed the case illustrated in Cox et al article > > https://www.sciencedirect.com/science/article/pii/S0021999116001686?casa_token=Vpk3uWyaxE0AAAAA:IGLI-wLZFaIwfIIOyPM1OZH6-TphsFXG3nTrgAbaSuJkzNJrUbAYDcL-qc9R1WINd9qGIA > It is a double periodic 2D manufactured solution case, the u, v source > terms are evaluated using Mathematica > I attach the ini file here > The Re = 10 > I calculated the order of accuracy in the manner described in the article > which is fairly straightforward > <image.png> > <image.png> > where eps_k is the difference between the exact solution and the numerical > solution. > I used the same meshes resolutions as the article 4x4, 8x8, 16x16, 32x32 > with double periodic bcs generated using gmsh > > For now, I am only trying to verify the spatial accuracy so following the > article's example I am using very small dt > I tried different zeta values, different pseudo-dt,, more > pseudo-niters-max going as high as 50 which is killing my performance > the only part I did not mess with is the LDG beta and tau > I double-checked the source terms several times but it seems okay > So I am not sure what could be the problem. > > Appreciate your help. > M Kamra > > > > On Tue, Oct 6, 2020 at 23:51 Vincent, Peter E <[email protected]> > wrote: > >> Hi M Karma, >> >> Could you provide more details of the test case, the way your are >> obtaining the order of accuracy, and the results that you are getting. >> >> Thanks >> >> Peter >> >> Professor of Computational Fluid Dynamics and EPSRC Fellow >> Department of Aeronautics >> Imperial College London >> South Kensington >> London >> SW7 2AZ >> UK >> >> >> >> >> >> >> >> On 6 Oct 2020, at 15:47, mkamra <[email protected]> wrote: >> >> Hello Everyone, >> >> I have a question regarding the order of accuracy of the ACM method; Have >> you done any tests using the method of manufactured solutions ( published >> or otherwise) ? >> >> I tried the 2D taylor green benchmark but the order of accuracy I am >> getting is nowhere near what it should be. When comparing with exact >> solution I used the solution points directly not the subdivided solution in >> the vtu file to avoid interpolation issues polluting the order of accuracy >> >> Also regarding the ACM, how would one obtain the residual of the >> continuity and momentum equations? Pseudo-stats only report the change >> between two consecutive pseudo iterations >> >> >> Regards, >> >> M Kamra >> >> >> >> -- >> You received this message because you are subscribed to the Google Groups >> "PyFR Mailing List" 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/pyfrmailinglist/fc58961d-02b2-4e7b-a05b-62af91f93537n%40googlegroups.com >> <https://groups.google.com/d/msgid/pyfrmailinglist/fc58961d-02b2-4e7b-a05b-62af91f93537n%40googlegroups.com?utm_medium=email&utm_source=footer> >> . >> >> >> > -- > You received this message because you are subscribed to the Google Groups > "PyFR Mailing List" 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/pyfrmailinglist/CAHrgCm7h18kXm-dUA%2BmfZH%2BK8bw1kfbpBnEdLyxORnpfV%3DFvrw%40mail.gmail.com > <https://groups.google.com/d/msgid/pyfrmailinglist/CAHrgCm7h18kXm-dUA%2BmfZH%2BK8bw1kfbpBnEdLyxORnpfV%3DFvrw%40mail.gmail.com?utm_medium=email&utm_source=footer> > . > <tg2d.ini> > > > -- You received this message because you are subscribed to the Google Groups "PyFR Mailing List" 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/pyfrmailinglist/CAHrgCm5yZbK-rfhP3tp%3DE_QM4W_wrtXyzPJrRZo2ZENFf0_VPw%40mail.gmail.com.
