Hi Kilian, thanks for your answer. Actually i followed your instruction. But because i use the CompressibleFlowSolver and APESolver there is no direct possibility to connect the variables u and v (for example: <F VAR="u0" FILE="Mesh2D50.rst:(rhou/rho)" /> or <F VAR="u0" FILE="Mesh2D50.rst:u" /> i get the error "Field not fount"). Mesh2D50.rst is my solution of the CompressiblyFlowSolver. Do you know a possibility to connect them in the right way? I think the connection of u with rhou and v with rhov might be wrong, but when i do so the simulation generates no error, but the visualization with paraview does not develop (just only a constant field of fluctuations p,u,v equal to zero). Is it right just only to connect the solvers by putting the solution of the CompressibleFlowSolver into the base-flow of the APESolver conditions and put the source (S) and initial-conditions (u,v,p) to zero? In my opinion i should at least change the initial conditions of the fluctuations and connect them with the solution of the CompressibleFlow-field (if possible) or what do you think? This is my code of the APE-conditions (first without the time-dependency and with the same mesh): <?xml version="1.0" encoding="utf-8"?> <NEKTAR> <EXPANSIONS> <E COMPOSITE="C[36]" BASISTYPE="GLL_Lagrange,GLL_Lagrange" NUMMODES="2,2" POINTSTYPE="GaussLobattoLegendre,GaussLobattoLegendre" NUMPOINTS="4,4" FIELDS="p,u,v"/> </EXPANSIONS> <CONDITIONS> <SOLVERINFO> <I PROPERTY="EQType" VALUE="APE"/> <I PROPERTY="Projection" VALUE="DisContinuous"/> <I PROPERTY="TimeIntegrationMethod" VALUE="RungeKutta2_ImprovedEuler"/> <I PROPERTY="UpwindType" VALUE="APEUpwind"/> </SOLVERINFO> <PARAMETERS> <P> TimeStep = 0.00001 </P> <P> NumSteps = 1000 </P> <P> FinTime = TimeStep*NumSteps </P> <P> IO_CheckSteps = 100 </P> <P> IO_InfoSteps = 1 </P> <P> rhoInf = 1.0 </P> <P> Gamma = 1.4 </P> <P> pInf = 1/1.4 </P> <P> Mach = 0.1 </P> <P> cInf = 1.0 </P> <P> alpha = 0.0 </P> <P> uInf = Mach*cInf*cos(alpha*PI/180) </P> <P> vInf = Mach*cInf*sin(alpha*PI/180) </P> </PARAMETERS> <VARIABLES> <V ID="0"> p </V> <V ID="1"> u </V> <V ID="2"> v </V> </VARIABLES> <BOUNDARYREGIONS> <B ID="0"> C[32] </B> <!-- left inflow --> <B ID="1"> C[33] </B> <!-- up and down --> <B ID="2"> C[34] </B> <!-- right outlow --> <B ID="3"> C[35] </B> <!-- NACA --> </BOUNDARYREGIONS> <BOUNDARYCONDITIONS> <REGION REF="0"> <D VAR="p" VALUE="0" /> <D VAR="u" VALUE="0" /> <D VAR="v" VALUE="0" /> </REGION> <REGION REF="1"> <D VAR="p" VALUE="0" /> <D VAR="u" VALUE="0" /> <D VAR="v" VALUE="0" /> </REGION> <REGION REF="2"> <D VAR="p" VALUE="0" /> <D VAR="u" VALUE="0" /> <D VAR="v" VALUE="0" /> </REGION> <!-- Wall --> <REGION REF="3"> <D VAR="p" USERDEFINEDTYPE="Wall" VALUE="0" /> <D VAR="u" USERDEFINEDTYPE="Wall" VALUE="0" /> <D VAR="v" USERDEFINEDTYPE="Wall" VALUE="0" /> </REGION> </BOUNDARYCONDITIONS> <FUNCTION NAME="Baseflow"> <!-- base flow --> <F VAR="u0" FILE="Mesh2D50.rst:(rhou/rho)" /> <!-- for u or rhou/rho not found, --> <F VAR="v0" FILE="Mesh2D50.rst:(rhov/rho)" /> <!-- for v or rhov/rho not found --> <F VAR="p0" FILE="Mesh2D50.rst:p" /> <F VAR="rho0" FILE="Mesh2D50.rst:rho" /> </FUNCTION> <FUNCTION NAME="Source"> <E VAR="S" VALUE="0" /> </FUNCTION> <FUNCTION NAME="ExactSolution"> <!-- Not really the exact solution --> <E VAR="p" VALUE="0" /> <E VAR="u" VALUE="0" /> <E VAR="v" VALUE="0" /> </FUNCTION> <FUNCTION NAME="InitialConditions"> <E VAR="p" VALUE="0" /> <E VAR="u" VALUE="0" /> <E VAR="v" VALUE="0" /> </FUNCTION> </CONDITIONS> </NEKTAR> Thanks for any hint! Cheers, Fabian ________________________________________ Von: Kilian Lackhove [lackhove@ekt.tu-darmstadt.de] Gesendet: Montag, 18. Juli 2016 16:39 An: nektar-users@imperial.ac.uk Cc: Selbach, Fabian Betreff: Re: [Nektar-users] Coupling CompressibleFlowSolver and APESolver to simulate the acoustic of a NACA-profile Hi Fabian, As of today, the easiest way to achieve what you described would be to run the CompressibleFlowSolver as usual and use the .chk files it creates as basefields for the APESolver as described in the userguide section 3.3.6.2. In case you have different meshes for the CompressibleFlowSolver and APESolver, you will have to convert the chk files to pts files first, so that the APESolver can interpolate them to during runtime. This interpolation will be horribly slow in the currently released versions, so you probably want to use the current master branch which it will only take a few seconds for the same task. The different naming of variables can be handled as described in section 3.3.6.1. I don't think we have the functionality to compute the acoustic source term in Nektar++, but since the pts files are just simple text files, this can be done in any postprocessing tool. Cheers, Kilian Am Montag, 18. Juli 2016, 13:32:30 CEST schrieb Selbach, Fabian:

Hello,

i have a question about coupling two solvers. First of all i make a simulation with a NACA-profile by using the NavierStokesCFE of the CompressibleFlowSolver. The solution of this i want to use to simulate the acoustic of its by solving the APE-equation. Is there an easy way to couple both solver and to simulate the acoustic of the flow around a NACA-profile?

I need the acoustic source terms (c²*qc) for the APE-Solver to simulate the sound. I should get those by the solution of the NACA flow (by the CompressibleFlowSolver), but i actually i do not see a possible to get them. Is there a way or do i have to program it's on my own into the code of the CompressibleFlowSolver to handle and couple them into the APESolver?

The difference between the solver-variables p, u and v ( in the CompressibleFlowSolver the absolute values and in the APESolver the fluctuations) i solved by calculating them in form of p(APE) = p(CFS) - pInf and so on.

I hope somebody can give me an answer. Thank you already!

Best regards

Fabian _______________________________________________ Nektar-users mailing list Nektar-users@imperial.ac.uk https://mailman.ic.ac.uk/mailman/listinfo/nektar-users -- Kilian Lackhove, M.Sc. Fachgebiet für Energie- und Kraftwerkstechnik L1|08 114 Technische Universität Darmstadt Jovanka-Bontschits-Straße 2 D-64287 Darmstadt Germany

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