[albertokarkour]

Hey guys! I'm new over here (and also in OpenFoam) my name is Alberto I'm from Venezuela.

I'd like some help about in trying to do a conduction heat transfer case of a solid so from what I've investigated the solver used is laplacianFoam. I did the tutorial that has the flange.ans file and everything was ok.

But now the case I'm trying to do instead of two fixed temperatures has fixed temperatures and a heat flux. Here is the case:

Consider a rectangular domain in which a=1m and b=0.8m. The thermal conductivity is k=1.2 W/(m*C). A heat flux q=500W/m2 enters the domain from the upper boundary and the temperatures of the other boundaries are all fixed at u1=0 celcius degrees

I think my mistake is in the 0/T boundary condition fixedGradient. Can someone tell me if I'm inserting it the correct way? Thanks in advance!

/*--------------------------------*- C++ -*----------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  3.0.x                                 |
|   \\  /    A nd           | Web:      www.OpenFOAM.org                      |
|    \\/     M anipulation  |                                                 |
\*---------------------------------------------------------------------------*/
FoamFile
{
    version     2.0;
    format      ascii;
    class       volScalarField;
    object      T;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

dimensions      [0 0 0 1 0 0 0];

internalField   uniform 0;

boundaryField
{

        
    fixedWalls
    {
        type            fixedValue;
        value           uniform 0;
    }

    heatWall
    {
        type            fixedGradient;
        value           uniform 416.67;
    }

    frontAndBack
    {
        type            empty;
    }
}

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

[HenningW]

First of all: I have not worked with heat transfer or this solver.

Since you posted here, I assume something is not working? What exactly is the problem you are facing that your calculation seems to fail? Do you get an error message? Is the solution unrealistic?

[albertokarkour]

Thanks for your reply! Well in the OpenFoam UserGuide says

laplacianFoam solves a simple Laplace equation, e.g for thermal diffusion in a solid

so I think is ok.
Yes, I get an error and is when I run the solver:

--> FOAM FATAL IO ERROR:
keyword gradient is undefined in dictionary

[HenningW]

It already tells you that the keyword gradient is missing in line 34. Try "gradient" instead of "value"

Edit: By the way, this post had the same problem

http://www.cfd-online.com/Forums/ope...tml#post217991

Edit 2: Not sure if it works in a windows environment, but if you can, try to create log files. Makes life a bit easier when posting things here
(For example: "simpleFoam 2>&1 | tee simple.log")

[albertokarkour]

Yes! That was the solution! Put gradient instead of value! Thanks so much!!!