[giusepp93]

Hi Foamers!
i am trying to implement a case with buoyantBoussinesqSimpleFoam. The geometry is simple, a pipe, and i want to set a costant heat flux q on walls using externalWallHeatFluxTemperature Bc. I tried to do it, but my simulation crashed.

FOAM FATAL ERROR:

request for solidThermo thermophysicalProperties from objectRegistry region0 failed
available objects of type solidThermo are
0()

From function objectRegistry::lookupObject<Type>(const word&) const
in file /home/giuseppe/OpenFOAM/OpenFOAM-2.3.1/src/OpenFOAM/lnInclude/objectRegistryTemplates.C at line 198.

thanks a lot
Giuseppe

[zfaraday]

Hi Giuseppe, it seems you have chosen solidThermo in thermophysicalProperties file. You should try with another option since this solver is not for solids... If you don't know what is the proper type to be used just do the banana trick! You know, just write banana in the place of the field you don't know the name to be used and run again the solver so that it will complain and tell you the available options.

Best regards,

Alex

[giusepp93]

Hi dear @Alex , thanks a lot for your useful reply. Actually i solved already that 'problem' implementing my temperature like this :
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 300;
}
wall
{
type externalWallHeatFluxTemperature;
q uniform 1000;
kappa lookup;
kappaName k;
thicknessLayers (1e-3) ;
kappaLayers (55) ;
value uniform 300;
QrName none;

}
outlet
{
type zeroGradient;
}
}

So the simulation worked but i didn't obtain good results (Tvalues too high). My case is the simplest one, but it seems so difficult with OpenFoam. I set a liquid flow inside a pipe with a constant velocity, a fixed temperature at the beginning and so, after the constant heat flux action on wall, i want to know how the temperature increase ( setting the enhancemente of thermal conductivity, convective heat flux coefficient, and other parameters that change with temperature, such as cp rho nu). i don't care about radiation and conduction, i just want to evaluate my fluid. I'm quite new to openfoam so surely i'm doing some mistake.I will post my case setting. Thanks a lot for your availability.
Best regards

Giuseppe

[giusepp93]

here there is my case. I think my solver (buoyantBoussinesqSimpleFoam) ignores my thermophysicalProperties, where i set the values depending on temperature. I am also not sure about my boundary condition, because i want just to focus about convective flux, so maybe that boundaries on temperature is wrong.
I hope u, or someone so smart like u, can help me.

[a19910112a]

I'm not sure if this is still useful to giusepp93, however, I will just post what I think about his code.

I did not look at his case but I looked at his cod at Posts 5.

firstly, you should set ( h and Ta ) or ( q ).

Secondly

kappaName       k;

Ｔｈａｔ ｉｓ ｎｏｔ ａ ｃｏｒｒｅｃｔ ｓｅｔｔｉｎｇ ａｓ ｔｈｅ ｓｏｌｖｅｒ ｗｉｌｌ ｆｉｎｄ ａ ｔｈｅ ｆｉｅｌｄ ｎａｍｅｄ ‘k’ and use that as the value of kappa. 'k' field that already exit is the k for k-epsilon model, rather than a kappa.

what you could do instead:
If your velocity is small enough, you could add the flowing code to the solveｒ:

volScalarField kappaEff("kappaEff", alphaEff*rho*Cp);

That is only usable when your convection effect is very small.

Maybe zfaraday could explain more about this, as I'm totally not a CFD guy.

Also I wonder if anyone have attempted to use the q option, I was not able to produce similar results using these two options mentioned in the first comment.