[Adam_K]

Hello,

I am trying to solve a two-phase heat transfer problem with two solid phases (see this figure) using the chtMultiRegionFoam solver. The analytical solution is known and for a thin (200 um) slab the simulation replicates it well with an adjustable timestep with maxDi = 1.

The solver appears to have settled on a time step of about 7 ns, sticking with that time step for the entire simulation of 1 ms. This does not appear logical to me as I would have expected a smaller time step initially and then a larger one as the temperature profile approaches equilibrium.

Is the time step supposed to adjust each time? Or does it just perform one adjustment initially?

Here is a link to the case file on DropBox.

Here is my controlDict file:

/*--------------------------------*- C++ -*----------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  5                                     |
|   \\  /    A nd           | Web:      www.OpenFOAM.org                      |
|    \\/     M anipulation  |                                                 |
\*---------------------------------------------------------------------------*/
FoamFile
{
    version     2.0;
    format      ascii;
    class       dictionary;
    location    "system";
    object      controlDict;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

application     chtMultiRegionFoam;

startFrom       latestTime;

startTime       0;

stopAt          endTime;

endTime         1e-3;

deltaT          1e-7;

writeControl    runTime;

writeInterval   1e-4;

purgeWrite      0;

writeFormat     ascii;

writePrecision  8;

writeCompression off;

timeFormat      general;

timePrecision   8;

runTimeModifiable yes;

adjustTimeStep  yes;

maxDeltaT       1e-5;
maxDi           1;

functions 
{ 
    #includeFunc  probesMatrix
    #includeFunc  probesFibres
} 

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

[Tobi]

Please provide a simple test case to check it.

[Adam_K]

Originally Posted by Tobi

Please provide a simple test case to check it.

Thanks for the suggestion, I thought it may have been some syntax issue that I was missing in my controlDict file.

I updated the original post with in image of my system and a link to my case file on DropBox.