[Nektar-users] Implementation of Force Type "MovingReferenceFrame" in Nektar++

31 May 2019

      Hi all,

I intend to solve the Incompressible Navier Stokes equations in a rotating
reference frame. Hence, I am adding the frame velocity of the rotating
frame as a Force Type = "MovingReferenceFrame". Will it add the appropriate
Coriolis term? Also, does the implementation 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 *
*Department of Mechanical Engineering*
*IIT Kharagpur*