******************* This email from josuelkr@gmail.com originated outside Imperial. ******************* Dear Nektar users, I am doing some tests using IncNavierStokes solver + steady driver (with default parameters) + periodic boundary conditions. I wonder if someone has to take some extra care if one of the boundaries is similar to a sawtooth wave, as an example. Specifically, I took initially a 2D-Couette flow. After that, I substituted one of the flat walls to a tilted small square step. Results seems to be nonphysical. I played with different meshes and time integration methods but could not draw any conclusion. My .xml file solver info is: <SOLVERINFO> <I PROPERTY="SolverType" VALUE="VelocityCorrectionScheme"/> <I PROPERTY="TimeIntegrationMethod" VALUE="IMEXOrder2"/> <I PROPERTY="EQTYPE" VALUE="UnsteadyNavierStokes"/> <I PROPERTY="AdvectionForm" VALUE="Convective"/> <I PROPERTY="Projection" VALUE="Galerkin"/> <I PROPERTY="Driver" VALUE="SteadyState"/> </SOLVERINFO> <EXPANSIONS> <E COMPOSITE="C[0]" NUMMODES="12" TYPE="MODIFIED" FIELDS="u,v,p" /> </EXPANSIONS> Any help would be appreciated. Thank you in advance, J PS: I can provide .xml and .geo files I am working with if necessary.
******************* This email from sgepner@meil.pw.edu.pl originated outside Imperial. ******************* Hi Josuel, I would suggest using the Standard Driver and time integrate to the steady state solution. In my experience this is faster and easier to do than to use the SFD method. Possibly, someone has had success with the SteadyState driver and can share a secret? Cheers, Stan On pon, 2019-12-02 at 21:37 -0500, Josuel Kruppa Rogenski wrote:
******************* This email from josuelkr@gmail.com originated outside Imperial. ******************* Dear Nektar users,
I am doing some tests using IncNavierStokes solver + steady driver (with default parameters) + periodic boundary conditions.
I wonder if someone has to take some extra care if one of the boundaries is similar to a sawtooth wave, as an example.
Specifically, I took initially a 2D-Couette flow. After that, I substituted one of the flat walls to a tilted small square step. Results seems to be nonphysical. I played with different meshes and time integration methods but could not draw any conclusion.
My .xml file solver info is: <SOLVERINFO> <I PROPERTY="SolverType" VALUE="VelocityCorrectionScheme"/> <I PROPERTY="TimeIntegrationMethod" VALUE="IMEXOrder2"/> <I PROPERTY="EQTYPE" VALUE="UnsteadyNavierStokes"/> <I PROPERTY="AdvectionForm" VALUE="Convective"/> <I PROPERTY="Projection" VALUE="Galerkin"/> <I PROPERTY="Driver" VALUE="SteadyState"/> </SOLVERINFO>
<EXPANSIONS> <E COMPOSITE="C[0]" NUMMODES="12" TYPE="MODIFIED" FIELDS="u,v,p" /> </EXPANSIONS>
Any help would be appreciated. Thank you in advance, J
PS: I can provide .xml and .geo files I am working with if necessary. _______________________________________________ Nektar-users mailing list Nektar-users@imperial.ac.uk https://mailman.ic.ac.uk/mailman/listinfo/nektar-users
Hi Stan, Josuel, I think we have had a few people play with the SFD (Mohammad is currently trying it) however if you are able to get the steady state by simply time marking the flow then that will likely be quicker. The SFD is more useful if you cannot get the steady state overwise. I am not aware that we managed to get the full Newton iteration to run correctly since it needs a good initial condition. Cheers, Spencer.
On 4 Dec 2019, at 09:32, Stanisław Gepner <sgepner@meil.pw.edu.pl> wrote:
******************* This email from sgepner@meil.pw.edu.pl originated outside Imperial. ******************* Hi Josuel,
I would suggest using the Standard Driver and time integrate to the steady state solution. In my experience this is faster and easier to do than to use the SFD method.
Possibly, someone has had success with the SteadyState driver and can share a secret?
Cheers, Stan
On pon, 2019-12-02 at 21:37 -0500, Josuel Kruppa Rogenski wrote:
******************* This email from josuelkr@gmail.com originated outside Imperial. ******************* Dear Nektar users,
I am doing some tests using IncNavierStokes solver + steady driver (with default parameters) + periodic boundary conditions.
I wonder if someone has to take some extra care if one of the boundaries is similar to a sawtooth wave, as an example.
Specifically, I took initially a 2D-Couette flow. After that, I substituted one of the flat walls to a tilted small square step. Results seems to be nonphysical. I played with different meshes and time integration methods but could not draw any conclusion.
My .xml file solver info is: <SOLVERINFO> <I PROPERTY="SolverType" VALUE="VelocityCorrectionScheme"/> <I PROPERTY="TimeIntegrationMethod" VALUE="IMEXOrder2"/> <I PROPERTY="EQTYPE" VALUE="UnsteadyNavierStokes"/> <I PROPERTY="AdvectionForm" VALUE="Convective"/> <I PROPERTY="Projection" VALUE="Galerkin"/> <I PROPERTY="Driver" VALUE="SteadyState"/> </SOLVERINFO>
<EXPANSIONS> <E COMPOSITE="C[0]" NUMMODES="12" TYPE="MODIFIED" FIELDS="u,v,p" /> </EXPANSIONS>
Any help would be appreciated. Thank you in advance, J
PS: I can provide .xml and .geo files I am working with if necessary. _______________________________________________ Nektar-users mailing list Nektar-users@imperial.ac.uk https://mailman.ic.ac.uk/mailman/listinfo/nektar-users
_______________________________________________ Nektar-users mailing list Nektar-users@imperial.ac.uk https://mailman.ic.ac.uk/mailman/listinfo/nektar-users
Spencer Sherwin FREng, FRAeS Head, Aerodynamics, Director of Research Computing Service, Professor of Computational Fluid Mechanics, Department of Aeronautics, s.sherwin@imperial.ac.uk South Kensington Campus, Phone: +44 (0)20 7594 5052 Imperial College London, Fax: +44 (0)20 7594 1974 London, SW7 2AZ, UK http://www.imperial.ac.uk/people/s.sherwin/
******************* This email from josuelkr@gmail.com originated outside Imperial. ******************* Hey Dr. Gepner, Professor Sherwin, Thank you for reply. I will shift to standard driver and see what happens. Best, J On Wed., Dec. 4, 2019, 11:43 a.m. Sherwin, Spencer J, < s.sherwin@imperial.ac.uk> wrote:
Hi Stan, Josuel,
I think we have had a few people play with the SFD (Mohammad is currently trying it) however if you are able to get the steady state by simply time marking the flow then that will likely be quicker. The SFD is more useful if you cannot get the steady state overwise.
I am not aware that we managed to get the full Newton iteration to run correctly since it needs a good initial condition.
Cheers, Spencer.
On 4 Dec 2019, at 09:32, Stanisław Gepner <sgepner@meil.pw.edu.pl> wrote:
******************* This email from sgepner@meil.pw.edu.pl originated outside Imperial. ******************* Hi Josuel,
I would suggest using the Standard Driver and time integrate to the steady state solution. In my experience this is faster and easier to do than to use the SFD method.
Possibly, someone has had success with the SteadyState driver and can share a secret?
Cheers, Stan
On pon, 2019-12-02 at 21:37 -0500, Josuel Kruppa Rogenski wrote:
******************* This email from josuelkr@gmail.com originated outside Imperial. ******************* Dear Nektar users,
I am doing some tests using IncNavierStokes solver + steady driver (with default parameters) + periodic boundary conditions.
I wonder if someone has to take some extra care if one of the boundaries is similar to a sawtooth wave, as an example.
Specifically, I took initially a 2D-Couette flow. After that, I substituted one of the flat walls to a tilted small square step. Results seems to be nonphysical. I played with different meshes and time integration methods but could not draw any conclusion.
My .xml file solver info is: <SOLVERINFO> <I PROPERTY="SolverType" VALUE="VelocityCorrectionScheme"/> <I PROPERTY="TimeIntegrationMethod" VALUE="IMEXOrder2"/> <I PROPERTY="EQTYPE" VALUE="UnsteadyNavierStokes"/> <I PROPERTY="AdvectionForm" VALUE="Convective"/> <I PROPERTY="Projection" VALUE="Galerkin"/> <I PROPERTY="Driver" VALUE="SteadyState"/> </SOLVERINFO>
<EXPANSIONS> <E COMPOSITE="C[0]" NUMMODES="12" TYPE="MODIFIED" FIELDS="u,v,p" /> </EXPANSIONS>
Any help would be appreciated. Thank you in advance, J
PS: I can provide .xml and .geo files I am working with if necessary. _______________________________________________ Nektar-users mailing list Nektar-users@imperial.ac.uk https://mailman.ic.ac.uk/mailman/listinfo/nektar-users
_______________________________________________ Nektar-users mailing list Nektar-users@imperial.ac.uk https://mailman.ic.ac.uk/mailman/listinfo/nektar-users
Spencer Sherwin FREng, FRAeS Head, Aerodynamics, Director of Research Computing Service, Professor of Computational Fluid Mechanics, Department of Aeronautics, s.sherwin@imperial.ac.uk South Kensington Campus, Phone: +44 (0)20 7594 5052 Imperial College London, Fax: +44 (0)20 7594 1974 London, SW7 2AZ, UK http://www.imperial.ac.uk/people/s.sherwin/
_______________________________________________ Nektar-users mailing list Nektar-users@imperial.ac.uk https://mailman.ic.ac.uk/mailman/listinfo/nektar-users
participants (3)
-
Josuel Kruppa Rogenski
-
Sherwin, Spencer J
-
Stanisław Gepner