[HumanistEngineer]

My case is with the transient solver for buoyant, turbulent flow of incompressible fluids (i.e. water) by use of buoyantFoam. The idea here is to mimic the temperature transients of the sensible stratified heat storage tank with one inlet-outlet configuration.

I could manage to have a (not verified) solution for a 3D simulation, see: https://youtu.be/VYZ0ZFjI1lE

In order to reduce the computational cost, I would like to apply a 2D Axisymmetric solution for the same geometry. Then I had difficulties with the issue that the temperature degrees go beyond the physical range defined (internal volume at 25 deg-C at the initial condition with an inlet of 55 deg-C at the boundary condition) with a FOAM FATAL ERROR:

--> FOAM FATAL ERROR: 
Maximum number of iterations exceeded: 100

I've attached the files in tar including:
- gmsh geo file
i. export the mesh as msh (version 2)
ii. gmshToFoam
iii. use the boundary below
- openfoam files required (0, Constant, and System)

/*--------------------------------*- C++ -*----------------------------------*\
  =========                 |
  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
   \\    /   O peration     | Website:  https://openfoam.org
    \\  /    A nd           | Version:  10
     \\/     M anipulation  |
\*---------------------------------------------------------------------------*/
FoamFile
{
    format      ascii;
    class       polyBoundaryMesh;
    location    "constant/polyMesh";
    object      boundary;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

7
(
    outlet
    {
        type            patch;
        physicalType    patch;
        nFaces          2;
        startFace       1831;
    }
    wedge_1
    {
        type            wedge;
        physicalType    wedge;
        nFaces          978;
        startFace       1833;
    }
    wedge_2
    {
        type            wedge;
        physicalType    wedge;
        nFaces          978;
        startFace       2811;
    }
    diffuser
    {
        type            empty;
        physicalType    empty;
        nFaces          78;
        startFace       3789;
    }
    inlet
    {
        type            patch;
        physicalType    patch;
        nFaces          2;
        startFace       3867;
    }
    walls
    {
        type            wall;
        physicalType    wall;
        nFaces          84;
        startFace       3869;
    }
    defaultFaces
    {
        type            empty;
        nFaces          22;
        startFace       3953;
    }
)

// ************************************************************************* //