Help with using DIRK Time Integration Methods
******************* This email 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. ******************* Hello everyone, I'm trying to use the DIRK Time Integration methods in the CompressibleFlowSolver but keep getting an error when trying to specify the order and variant. If I specify only <I PROPERTY="TimeIntegrationMethod" VALUE="DIRK" /> in SolverInfo it will work perfectly, however I am unsure which order this is using. When I try to define VALUE="DIRKOrder3" or in a separate TIMEINTEGRATIONSCHEME section as below instead, it will produce the error bad_function_call. <TIMEINTEGRATIONSCHEME> <METHOD> DIRK </METHOD> <ORDER> 3 </ORDER> </TIMEINTEGRATIONSCHEME> Could anyone clarify: 1. Which order is used for the default "DIRK" model? 2. What would be the correct way to specify the order of DIRK model? Thank you in advance, Andrew
Hi Andrew, Based on the test case for the compressible flow solver: CylinderSubsonic_WeakDG_Implicit.xml The order of the DIRK time-integration scheme is specified as: <I PROPERTY="TimeIntegrationMethod" VALUE="DIRKOrder2" /> The same is applied to other test-cases that use DIRK as an integration scheme which are: * Tests/TimeDependentAbsorption.xml * Tests/implicitSolverCallsSFD_session.xml So in order to change the order of the DIRK time-integration scheme, you should something that looks like: <I PROPERTY="TimeIntegrationMethod" VALUE="DIRKOrder3" /> Unfortunately, I am not aware with the default order of the DIRK time-integration scheme. I hope this is helpful! Best wishes, Alexandra From: nektar-users-bounces@imperial.ac.uk <nektar-users-bounces@imperial.ac.uk> On Behalf Of Andrew Barnes Sent: 27 January 2023 10:03 To: Nektar mail list <nektar-users@imperial.ac.uk> Subject: [Nektar-users] Help with using DIRK Time Integration Methods This email from A.Barnes2@lboro.ac.uk <mailto:A.Barnes2@lboro.ac.uk> 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. Hello everyone, I'm trying to use the DIRK Time Integration methods in the CompressibleFlowSolver but keep getting an error when trying to specify the order and variant. If I specify only <I PROPERTY="TimeIntegrationMethod" VALUE="DIRK" /> in SolverInfo it will work perfectly, however I am unsure which order this is using. When I try to define VALUE="DIRKOrder3" or in a separate TIMEINTEGRATIONSCHEME section as below instead, it will produce the error bad_function_call. <TIMEINTEGRATIONSCHEME> <METHOD> DIRK </METHOD> <ORDER> 3 </ORDER> </TIMEINTEGRATIONSCHEME> Could anyone clarify: 1. Which order is used for the default "DIRK" model? 2. What would be the correct way to specify the order of DIRK model? Thank you in advance, Andrew
Hi Andrew, In our case we use second order and this is what we prescribe in the session file: <SOLVERINFO> [...] <I PROPERTY="TimeIntegrationMethod" VALUE="DIRKOrder2" /> [...] </SOLVERINFO> Cheers, Margarida On Fri, 27 Jan 2023 at 11:03, Andrew Barnes <A.Barnes2@lboro.ac.uk> wrote:
This email from A.Barnes2@lboro.ac.uk 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.
Hello everyone,
I'm trying to use the DIRK Time Integration methods in the CompressibleFlowSolver but keep getting an error when trying to specify the order and variant.
If I specify only <I PROPERTY="TimeIntegrationMethod" VALUE="DIRK" /> in SolverInfo it will work perfectly, however I am unsure which order this is using. When I try to define VALUE="DIRKOrder3" or in a separate TIMEINTEGRATIONSCHEME section as below instead, it will produce the error bad_function_call.
<TIMEINTEGRATIONSCHEME> <METHOD> DIRK </METHOD> <ORDER> 3 </ORDER> </TIMEINTEGRATIONSCHEME>
Could anyone clarify:
1. Which order is used for the default "DIRK" model? 2. What would be the correct way to specify the order of DIRK model?
Thank you in advance, Andrew _______________________________________________ Nektar-users mailing list Nektar-users@imperial.ac.uk https://mailman.ic.ac.uk/mailman/listinfo/nektar-users
-- Margarida Moragues Ginard MSCA-IF Researcher *BCAM - *Basque Center for Applied Mathematics Alameda de Mazarredo, 14 E-48009 Bilbao, Basque Country - Spain Tel. +34 946 567 842 mmoragues@bcamath.org | www.bcamath.org/mmoragues *(**matematika mugaz bestalde)*
Thank you both for your help ________________________________ From: Margarida Moragues Ginard <mmoragues@bcamath.org> Sent: 27 January 2023 10:19 To: Andrew Barnes <A.Barnes2@lboro.ac.uk> Cc: Nektar mail list <nektar-users@imperial.ac.uk> Subject: Re: [Nektar-users] Help with using DIRK Time Integration Methods ** THIS MESSAGE ORIGINATED OUTSIDE LOUGHBOROUGH UNIVERSITY ** ** Be wary of links or attachments, especially if the email is unsolicited or you don't recognise the sender's email address. ** Hi Andrew, In our case we use second order and this is what we prescribe in the session file: <SOLVERINFO> [...] <I PROPERTY="TimeIntegrationMethod" VALUE="DIRKOrder2" /> [...] </SOLVERINFO> Cheers, Margarida On Fri, 27 Jan 2023 at 11:03, Andrew Barnes <A.Barnes2@lboro.ac.uk<mailto:A.Barnes2@lboro.ac.uk>> wrote: This email from A.Barnes2@lboro.ac.uk<mailto:A.Barnes2@lboro.ac.uk> 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. Hello everyone, I'm trying to use the DIRK Time Integration methods in the CompressibleFlowSolver but keep getting an error when trying to specify the order and variant. If I specify only <I PROPERTY="TimeIntegrationMethod" VALUE="DIRK" /> in SolverInfo it will work perfectly, however I am unsure which order this is using. When I try to define VALUE="DIRKOrder3" or in a separate TIMEINTEGRATIONSCHEME section as below instead, it will produce the error bad_function_call. <TIMEINTEGRATIONSCHEME> <METHOD> DIRK </METHOD> <ORDER> 3 </ORDER> </TIMEINTEGRATIONSCHEME> Could anyone clarify: 1. Which order is used for the default "DIRK" model? 2. What would be the correct way to specify the order of DIRK model? Thank you in advance, Andrew _______________________________________________ Nektar-users mailing list Nektar-users@imperial.ac.uk<mailto:Nektar-users@imperial.ac.uk> https://mailman.ic.ac.uk/mailman/listinfo/nektar-users -- Margarida Moragues Ginard MSCA-IF Researcher BCAM - Basque Center for Applied Mathematics Alameda de Mazarredo, 14 E-48009 Bilbao, Basque Country - Spain Tel. +34 946 567 842 mmoragues@bcamath.org<mailto:mmoragues@bcamath.org> | www.bcamath.org/mmoragues<http://www.bcamath.org/mmoragues> (matematika mugaz bestalde)
Hi Andrew, My understanding is if you only specify <I PROPERTY="TimeIntegrationMethod" VALUE="DIRK" />, then the default order will be "1". A DIRK time-integration scheme of order 1 reduces to backward Euler. However, a DIRK time-integration scheme of order 1 is not currently defined in the code base (you have to use BackwardEuler). When use simply use "DIRK", have you checked the solution is being updated? Jacques ________________________________ From: nektar-users-bounces@imperial.ac.uk <nektar-users-bounces@imperial.ac.uk> on behalf of Andrew Barnes <A.Barnes2@lboro.ac.uk> Sent: Friday, January 27, 2023 10:02 AM To: Nektar mail list <nektar-users@imperial.ac.uk> Subject: [Nektar-users] Help with using DIRK Time Integration Methods Some people who received this message don't often get email from a.barnes2@lboro.ac.uk. Learn why this is important<https://aka.ms/LearnAboutSenderIdentification> This email from A.Barnes2@lboro.ac.uk 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://eur03.safelinks.protection.outlook.com/?url=https%3A%2F%2Fspam.ic.ac.uk%2FSpamConsole%2FSenders.aspx&data=05%7C01%7Cjacques.xing%40kcl.ac.uk%7Cd9ec82ec8cb2447f1b1808db004dcb93%7C8370cf1416f34c16b83c724071654356%7C0%7C0%7C638104106495972233%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000%7C%7C%7C&sdata=CaeTZxfyaVTGMozEq6XmWU1Eg32WvE5o4hAqwoeLWDo%3D&reserved=0> to disable email stamping for this address. Hello everyone, I'm trying to use the DIRK Time Integration methods in the CompressibleFlowSolver but keep getting an error when trying to specify the order and variant. If I specify only <I PROPERTY="TimeIntegrationMethod" VALUE="DIRK" /> in SolverInfo it will work perfectly, however I am unsure which order this is using. When I try to define VALUE="DIRKOrder3" or in a separate TIMEINTEGRATIONSCHEME section as below instead, it will produce the error bad_function_call. <TIMEINTEGRATIONSCHEME> <METHOD> DIRK </METHOD> <ORDER> 3 </ORDER> </TIMEINTEGRATIONSCHEME> Could anyone clarify: 1. Which order is used for the default "DIRK" model? 2. What would be the correct way to specify the order of DIRK model? Thank you in advance, Andrew
participants (4)
- 
                
                Andrew Barnes
- 
                
                Jacques Xing
- 
                
                liosi.alex@gmail.com
- 
                
                Margarida Moragues Ginard