Dear YiLin, I have had a look at the files you provided. To me it seems that you likely just have mistyped a value in your source term, which would be: alpha = ln(2)/9 = 0.0770 (you have it included as 0.77 in your casefiles). I did run and re-run the APE case with both your original settings and the corrected, lower alpha, and finally obtained amplitudes for the pressure of [-2.46; 0.64]. If I see that correctly, there is still a discrepancy to the analytical solution, but at least the values are in the right ballpark now. I hope that already helps you a bit. -- Best regards, --------------------------------------------------- Hanna Reinhardt, M.Sc. Research Associate Simulation of reactive Thermo-Fluid Systems (STFS) Technische Universität Darmstadt Otto-Berndt-Straße 2, 64287 Darmstadt Raum: L1|01 293 Tel: +49 6151 16 24144 Fax: +49 6151 16 24140 www.stfs.tu-darmstadt.de<http://www.stfs.tu-darmstadt.de> --------------------------------------------------- ________________________________ Von: nektar-users-bounces@imperial.ac.uk <nektar-users-bounces@imperial.ac.uk> im Auftrag von Paul Liu <liuyilin.liu@gmail.com> Gesendet: Montag, 31. Januar 2022 19:50 An: nektar-users@imperial.ac.uk Betreff: [Nektar-users] Acoustic Solver Case Questions This email from liuyilin.liu@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. Hi All, I am trying to run a simple case prescribing an exponential function that is sinusoidal in time for the energy equation in both APE and LEE solvers. I have the analytical solution for this case. The results from APE and LEE solvers agree with each other but the amplitude is quite different from the analytical solution. I have included a more detailed summary (pdf) and all the case setup files in the zip file. I was wondering if I messed up the setup for the cases or is there some kind of scaling on the variables that I am not aware of? Thank you all. YiLin Liu 403-397-3457 liuyilin.liu@gmail.com<mailto:liuyilin.liu@gmail.com> MASc Student at CML<https://cml.mech.ubc.ca/> UBC