[dnm2017]

Hi All,

I am looking to implement body forces at a source term in the rhoCentralFoam momentum calculation, to begin with just constant gravitational acceleration.

In createfields.h, I have defined:

volVectorField g
 (
     IOobject
     (
         "g",
         runTime.timeName(),
         mesh,
         IOobject::NO_READ,
         IOobject::AUTO_WRITE
     ),
     mesh,
   dimensionedVector("g", dimAcceleration, vector(0,-9.81,0))
);

volVectorField rhoG
(
    IOobject
    (
        "rhoG",
        runTime.timeName(),
        mesh,
        IOobject::NO_READ,
        IOobject::AUTO_WRITE
    ),
    thermo.rho()*g
);

Then in rhoCentralFoam.c

        // --- Solve momentum
        rhoG = rho * g; 
       //not sure if I need the above ^ ???
        solve(fvm::ddt(rhoU) + fvc::div(phiUp) - rhoG);

The output files for rhoG appears to be correct but doesn't produce the results I expect, for a cuboid box with only gravity acting, symmetry plane at the bottom (y_min) and zerogradient conditions everywhere else, initial pressure 101325pa, the pressure just continues to build up at y_min when I was expecting it to settle down.... I'm sure I'm just doing something stupid so if anyone could offer some advice that would be great.

Thanks
Dave