Hi Swagat,

The MovingReferenceFrame has been implemented only for constant
velocity of the Frame. That is it can not be a function of time and
space. So I am afraid it will not work the way you are trying to do it
here, only by putting appropriate values in the xml file.

What I meant is, that if you know what terms you need to add to the NS
equation, you could manipulate the source of Nektar - essentially write
a new Forcing function - very mych like the MovingReferenceFrame is
written. There the NS equation is supplemented by sth. like

c_x * \partial u / \partial x

with c_x the speed of the moving frame.

Cheers,
Stan

On pią, 2019-05-31 at 18:20 +0900, Swagat Kumar Nayak wrote:
> Hi Stanisław,
>
> Thanks for your reply. I checked the files. I think that if I add the
> frame velocity and the appropriate Initial and Boundary conditions,
> then I hope that it should work for me. Though, I am unsure about its
> implementation. Does the way I am implementing it, seem correct?
>
> <NEKTAR>
> <!-- Setting the Expansion Bases -->
>     <EXPANSIONS>
>         .............................
>     </EXPANSIONS>
>
> <!-- Setting the Filters to output Energy Details -->
>     <FILTERS>
>          .............................
>     </FILTERS>
>
> <!-- Setting the Boundary conditions and Solver information for the
> flow -->
>     <CONDITIONS>
>          <SOLVERINFO>
>          ..............................
>          </SOLVERINFO>
>
>          <PARAMETERS>
>          .............................
>          </PARAMETERS>
>
> <!-- Setting the Variables -->
>
>         <VARIABLES>
>                 <V ID="0"> u </V>
>                 <V ID="1"> v </V>
>                 <V ID="2"> w </V>
>                 <V ID="3"> p </V>
>         </VARIABLES>
>
> <!-- Setting the Boundary Conditions -->
>         <BOUNDARYREGIONS>
>                 ........................................
>         </BOUNDARYREGIONS>
>
>         <BOUNDARYCONDITIONS>
>                 .................................................
>         </BOUNDARYCONDITIONS>
>
> <!-- Setting the Initial conditions and the frame velocity
> (Precession frame) -->
>
>         <FUNCTION NAME="InitialConditions">
>                 <E VAR="u" VALUE="F(y)" />
>                 <E VAR="v" VALUE="G(x)" />
>                 <E VAR="w" VALUE="0" />
>                 <E VAR="p" VALUE="0" />
>         </FUNCTION>
>
>         <FORCE TYPE="MovingReferenceFrame">
>                 <FRAMEVELOCITY>
>                         <FUNCTION NAME="MovingReferenceFrame">
>                                 <E VAR="u" VALUE="f(y,z,t)" />
>                                 <E VAR="v" VALUE="g(y,z,t)" />
>                                 <E VAR="w" VALUE="0" />
>                         </FUNCTION>
>                 <FRAMEVELOCITY/>
>         </FORCE>
>
>     </CONDITIONS>
> </NEKTAR>
>
> Thank you !
> Swagat Kumar Nayak
>
> On Wed, May 29, 2019 at 7:14 PM Stanisław Gepner <
> sgepner@meil.pw.edu.pl> wrote:
> > Hi Swagat,
> >
> > Not sure anyone answered this.
> >
> > 1) You could try to add a Forcing term. Much like ForcingBody in
> > library/Solverutils/Forcing. I think something similar to what you
> > describe has been done for the moving reference frame
> > (ForcingMovingReferenceFrame) i.e. additional terms that are
> > gradient
> > of velocity.
> >
> > 2) At the end of the .geo file there is a protion where Physical
> > objects are declared. Sth. like:
> >
> > Physical Line(1) = {3,1,2,4};
> > Physical Surface(2) = {6};
> >
> > My experience with NekMesh is that composite 2 is the 2D domain and
> > composite 1 the boundary.
> >
> > Cheers,
> > Stan
> >
> > On czw, 2019-05-23 at 14:25 +0900, Swagat Kumar Nayak wrote:
> > > Hi everyone,
> > >
> > > I am trying to simulate the flow of a precessing cylinder in the
> > > cylinder frame of reference. I have got some additional terms in
> > the
> > > incompressible Navier-stokes equation which are velocity
> > dependent.
> > > (1) How do I add these additional terms to the incompressible
> > Navier-
> > > stokes equation?
> > >
> > > (2) When I create a mesh in Gmsh and try to convert it into the
> > .xml
> > > file format, how do I identify the composites corresponding to
> > the
> > > global boundaries?
> > >
> > > I am new to this framework. So, any help will be largely
> > appreciated.
> > >
> > >
> > > Thank you,
> > >
> > > _______________________________________________
> > > Nektar-users mailing list
> > > Nektar-users@imperial.ac.uk
> > > https://mailman.ic.ac.uk/mailman/listinfo/nektar-users
> >
>
>