CFD Online Discussion Forums - unexpected call for rho in modified buoyantBoussinesqSimpleFoam

Hej,

I have slightly modified buoyantBoussinesqSimpleFoam in order to implement a different way of calculating the temperature equation

Therefore the main file looks like this now

Code:

 Info<< "\nStarting time loop\n" << endl;



    while (simple.loop())

    {

        Info<< "Time = " << runTime.timeName() << nl << endl;



        // Pressure-velocity SIMPLE corrector

        {

            #include "UEqn.H"

            #include "AHFMEqn.H" // new

            #include "TEqn.H"

            #include "pEqn.H"

        }



        turbulence->correct();



        runTime.write();



        Info<< "ExecutionTime = " << runTime.elapsedCpuTime() << " s"

            << "  ClockTime = " << runTime.elapsedClockTime() << " s"

            << nl << endl;

    }



    Info<< "End\n" << endl;

where the highlighted part is a new equation that calculates a field for the temperature equation. It compiles and the temperature equation is solved. As can be seen from the output

Code:

SIMPLE: convergence criteria

    field p_rgh     tolerance 1e-08

    field T     tolerance 1e-06

    field U     tolerance 1e-06





Starting time loop



Time = 1



DILUPBiCG:  Solving for Ux, Initial residual = 1, Final residual = 0.0281127014, No Iterations 1

DILUPBiCG:  Solving for Uy, Initial residual = 1, Final residual = 0.0281177952, No Iterations 1

DILUPBiCG:  Solving for theta2, Initial residual = 0.999994784, Final residual = 0.0182097574, No Iterations 1

DILUPBiCG:  Solving for T, Initial residual = 1, Final residual = 0.0280023891, No Iterations 1

do p_rghEqn setup







--> FOAM FATAL ERROR: 



    request for volScalarField rho from objectRegistry region0 failed

    available objects of type volScalarField are

the "do p_rghEqn setup" comes from an info part that I now inserted into the pEqn.H part of the solver in order to find the error. For some unexplained reason the solver wants to look up rho in the pEqn.H part of the solver, even though that part is untouched as in

Code:

{

    volScalarField rAU("rAU", 1.0/UEqn().A());

    surfaceScalarField rAUf("(1|A(U))", fvc::interpolate(rAU));



    U = rAU*UEqn().H();

    UEqn.clear();



    phi = fvc::interpolate(U) & mesh.Sf();

    adjustPhi(phi, U, p_rgh);



    surfaceScalarField buoyancyPhi(rAUf*ghf*fvc::snGrad(rhok)*mesh.magSf());

    phi -= buoyancyPhi;



    while (simple.correctNonOrthogonal())

    {

        Info << "do p_rghEqn setup\n" << endl; // modification for debugging

        fvScalarMatrix p_rghEqn

        (

            fvm::laplacian(rAUf, p_rgh) == fvc::div(phi) // here comes the error

        );

        Info << "done p_rghEqn setup\n" << endl;  // modification for debugging

The pressure equation was never touched and a diff test reveals that the only changes between the original file in buoyantBoussinesqSimpleFoam and my version are the lines highlighted with "modification for debugging"

Does anybody know why and how the solver wants to look up rho?