[Humam121]

Hello, I'm extremely new to CFD and OpenFOAM. I want to simulate a fluid moving through a vertical 3d rectangular pipe. I'm using buoyantPimpleFoam for the solver because I'm planning to expand the case into a slightly more complex case, but I currently just want to see if I can simulate the flow of the fluid without any treatment.

I'm not sure why, but the fluid doesn't seem to be able to move to the top of the block (I look at the flow of the temperature in ParaView to check its flow). I've tried removing gravity (setting it to (0 0 0)) and it didn't help. The only way to get it to move normally is to set the internalField velocity to have the same value as the inlet velocity, but other cases that I have seen usually have the internalField velocity set to (0 0 0). I have tried looking for other threads with similar problem but couldn't find anything. I have tried using a different solver (scalarTransportFoam) with a horizontal pipe instead and I'm still encountering the same problem.

Here are the codes for 0/U and 0/T. I've also attached a picture from the paraView and the case file here (https://drive.google.com/file/d/1Akm...ew?usp=sharing)

0/U

FoamFile
{
    version     2.0;
    format      ascii;
    class       volVectorField;
    location    "288";
    object      U;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

dimensions      [0 1 -1 0 0 0 0];

internalField   uniform (0 0 0); 


boundaryField
{
    inlet
    {
    type    fixedValue;
    value    uniform (0 2 0);
    }

    outlet
    {
    type    zeroGradient;
    }
    walls
    {
    type    noSlip;
    }
 }

0/T file

FoamFile
{
    version     2.0;
    format      ascii;
    class       volScalarField;
    object      T;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

dimensions      [0 0 0 1 0 0 0];

internalField   uniform 300;

boundaryField
{
    inlet
    {
        type            fixedValue;
        value           uniform 600;
    }

    outlet
    {
        type            zeroGradient;
    }

    walls
    {
        type            zeroGradient;
    }
 }

Thanks in advance!