[pakanatiakash]

Hi All

I am using Openfoam 2.4.0 and installed swak4foam to use groovyBC. I am working on solidification problem and I need to apply a boundary condition on one of the walls for heat extraction. The expression is given by q = h*(T-Tinf), with h and Tinf as fixed values. T is the temperature of the domain at each step. I have the corresponding groovyBC code -

rightWall
{

type groovyBC;
value uniform 285.489;
valueExpression "flux";
variables "h=400.0;Tinf=25;flux=h*(Tinf-T);";
}

The initial temperature of the domain is 285.489 and thats the value I gave in the code above. If I understood it right, the would be the temperature for the first time step.

Coming to my problem, the flux is not being applied and when I visualize the results, the temperature of the wall stays 285.489. I am not quite sure what is going wrong. If I change the value of 285.489, the wall temperature is changing accordingly which leads me to conclude that the next two lines are not being read. Any idea what might be wrong?

[rapierrz]

Hi Akash,

Your mistakes:

1.for apply heat flux you must add below code to groovyBc:

gradientExpression "flux";

2.you must add this code for applying gradient boundary condition.

fractionExpression "0";

[pakanatiakash]

Hullo

Thank you for the response. I corrected the errors and the issues still exist. A little bit of probing has made me realise that I am solving the Heqn instead of Teqn. Do you think that might be a problem as I am not solving for temperature explicitly?

Cheers
Akash

[rapierrz]

First,Excuse me for my mistake on call your name in my last post.


My suggestion is that check that your groovyBc installed correctly or not.

Check that in initial times that case is running,error of groovyBc occur or not.

Then check that if you put valueExpression "0" and for example :

gradientExpression "10000"; it's OK or not.

Best regards

[zfaraday]

Hi Akash!

I think the problem comes from your variable specification. I think the variables should be defined within brackets and quotating one after another. For instance,

...
variables ("h=400.0;"
           "Tinf=25;"
           "flux=h*(Tinf-T);"
           );
...

Hope it helps.

Best regards,

Alex

[pakanatiakash]

thanks for the information. The problem I have is I am solving for H and I added an additional equation to solve for T. This fixed my problem!

Cheers
Akash