Solution of Navier Stokes equation with steady-state solver
Dear All, I want to solve a constricted pipe flow problem (for Re=100) using Navier Stokes equation with steady-state solver of Nektar++. By reading the user guide of Nektar++ I prepared solver info and parameters part of my xml file for this purpose as seen below: /* <SOLVERINFO>*//* *//* <I PROPERTY="EQTYPE" VALUE="SteadyLinearisedNS" />*//* *//* <I PROPERTY="Projection" VALUE="Continuous" />*//* *//* <I PROPERTY="Driver" VALUE="SteadyState" />*//* *//* <I PROPERTY="TimeIntegrationMethod" VALUE="IMEXOrder1" />*//* *//* </SOLVERINFO>*//* *//* *//* *//* <PARAMETERS>*//* *//* <P> ControlCoeff = 1 </P>*//* *//* <P> FilterWidth = 1 </P>*//* *//* <P> TOL = 10e-9 </P>*//* *//* <P> Kinvis = 0.1 </P>*//* *//* </PARAMETERS>*/ When I tried to run an analysis I got such an error: /*Fatal : Level 0 assertion violation*//* *//*EquationSystem 'SteadyLinearisedNS' is not defined.*//* *//*Ensure equation name is correct and module is compiled.*/ I also tried other equation types (Steady Stokes, Unsteady NS etc.) What is the source of this error? I also want to ask if it is possible to write a history file for steady solutions? Regards, Kamil
Dear Kamil, I am afraid a direct steady state solver is not available in 3D. We do have a linearised NS solver which runs in 2D and 2.5D but not 3D. I am cc’ing Bastien who has been working on a method call SFD which allows one to try and obtain steady state solutions using a time stepping scheme. (details can be found under http://arxiv.org/pdf/1311.7000.pdf). If you are interested Bastien could send you an example of how to run with this option. Cheers, Spencer. PS Chris/Bastien I have added the sapper to the nektar.info web page. Since we have the other paper on arxiv perhaps we could also put that one on the list as “under review”? On 5 Mar 2015, at 08:31, Kamil ÖZDEN <kamil.ozden.me@gmail.com<mailto:kamil.ozden.me@gmail.com>> wrote: Dear All, I want to solve a constricted pipe flow problem (for Re=100) using Navier Stokes equation with steady-state solver of Nektar++. By reading the user guide of Nektar++ I prepared solver info and parameters part of my xml file for this purpose as seen below: <SOLVERINFO> <I PROPERTY="EQTYPE" VALUE="SteadyLinearisedNS" /> <I PROPERTY="Projection" VALUE="Continuous" /> <I PROPERTY="Driver" VALUE="SteadyState" /> <I PROPERTY="TimeIntegrationMethod" VALUE="IMEXOrder1" /> </SOLVERINFO> <PARAMETERS> <P> ControlCoeff = 1 </P> <P> FilterWidth = 1 </P> <P> TOL = 10e-9 </P> <P> Kinvis = 0.1 </P> </PARAMETERS> When I tried to run an analysis I got such an error: Fatal : Level 0 assertion violation EquationSystem 'SteadyLinearisedNS' is not defined. Ensure equation name is correct and module is compiled. I also tried other equation types (Steady Stokes, Unsteady NS etc.) What is the source of this error? I also want to ask if it is possible to write a history file for steady solutions? Regards, Kamil _______________________________________________ Nektar-users mailing list Nektar-users@imperial.ac.uk<mailto:Nektar-users@imperial.ac.uk> https://mailman.ic.ac.uk/mailman/listinfo/nektar-users Spencer Sherwin McLaren Racing/Royal Academy of Engineering Research Chair, Professor of Computational Fluid Mechanics, Department of Aeronautics, Imperial College London South Kensington Campus London SW7 2AZ s.sherwin@imperial.ac.uk<mailto:s.sherwin@imperial.ac.uk> +44 (0) 20 759 45052
Dear Dr. Sherwin, Thanks for your reply. Sure, I want to learn how this method works at least for my possible future 2D works. If Bastien sends me an example, I'll be glad. Regards, Kamil On 05.03.2015 14:09, Sherwin, Spencer J wrote:
Dear Kamil,
I am afraid a direct steady state solver is not available in 3D. We do have a linearised NS solver which runs in 2D and 2.5D but not 3D.
I am cc’ing Bastien who has been working on a method call SFD which allows one to try and obtain steady state solutions using a time stepping scheme. (details can be found under http://arxiv.org/pdf/1311.7000.pdf).
If you are interested Bastien could send you an example of how to run with this option.
Cheers, Spencer.
PS *Chris/Bastien *I have added the sapper to the nektar.info web page. Since we have the other paper on arxiv perhaps we could also put that one on the list as “under review”?
On 5 Mar 2015, at 08:31, Kamil ÖZDEN <kamil.ozden.me@gmail.com <mailto:kamil.ozden.me@gmail.com>> wrote:
Dear All,
I want to solve a constricted pipe flow problem (for Re=100) using Navier Stokes equation with steady-state solver of Nektar++. By reading the user guide of Nektar++ I prepared solver info and parameters part of my xml file for this purpose as seen below:
/* <SOLVERINFO>*//* *//* <I PROPERTY="EQTYPE" VALUE="SteadyLinearisedNS" />*//* *//* <I PROPERTY="Projection" VALUE="Continuous" />*//* *//* <I PROPERTY="Driver" VALUE="SteadyState" />*//* *//* <I PROPERTY="TimeIntegrationMethod" VALUE="IMEXOrder1" />*//* *//* </SOLVERINFO>*//* *//* *//* *//* <PARAMETERS>*//* *//* <P> ControlCoeff = 1 </P>*//* *//* <P> FilterWidth = 1 </P>*//* *//* <P> TOL = 10e-9 </P>*//* *//* <P> Kinvis = 0.1 </P>*//* *//* </PARAMETERS>*/
When I tried to run an analysis I got such an error:
/*Fatal : Level 0 assertion violation*//* *//*EquationSystem 'SteadyLinearisedNS' is not defined.*//* *//*Ensure equation name is correct and module is compiled.*/
I also tried other equation types (Steady Stokes, Unsteady NS etc.) What is the source of this error?
I also want to ask if it is possible to write a history file for steady solutions?
Regards, Kamil
_______________________________________________ Nektar-users mailing list Nektar-users@imperial.ac.uk <mailto:Nektar-users@imperial.ac.uk> https://mailman.ic.ac.uk/mailman/listinfo/nektar-users
Spencer Sherwin McLaren Racing/Royal Academy of Engineering Research Chair, Professor of Computational Fluid Mechanics, Department of Aeronautics, Imperial College London South Kensington Campus London SW7 2AZ
s.sherwin@imperial.ac.uk <mailto:s.sherwin@imperial.ac.uk> +44 (0) 20 759 45052
participants (2)
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Kamil ÖZDEN
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Sherwin, Spencer J