Not able to find transmissivity

[Grab]

Dear Elmer users,

I used to work with heat radiation with opaque materials. Currently, I would like to start analyzing heat radiation with semi-transparent materials.
However, I am unable to find how to define the transmissivity of a material. In the Elmer Models Manual, it is specified after the emissivity but impossible to find it.
Please could one of you help me on this topic?

Best regards,
Ben

[kevinarden]

You can provide it in the boundary condition or the material property as
emissivity=1.0 (or whatever value you need)

[raback]

Hi,

It seems that the code expects "Transmittivity", not "Transmissivity". Maybe tells that it hasn't been too much used. It is not in keyword database so you need to cast the type "Real".

-Peter

[kevinarden]

Sorry I mis-read the post
So according to Peter
Transmittivity = Real 1.0

[Grab]

Thank you very much Kevin and Peter for your reply.

I forgot to mention one important thing : I am using ElmerGUI, and the transmissivity (or transmittivity) does not appear anywhere as far as I know.

Would it be taken into account if I include it in the material file (the .xlm in the Elmer folder)?

Thanks again for your help!
Ben

[kevinarden]

On any of the forms in ElmerGUI you can use the free text input block and it will add any text you type to that section.

[raback]

...and you can also add it to the "heatequation.xml" file.

Btw, I changed the name in the code to "transmissivity". An updated binary will complain about "transmittivity". The former was clear winner in google fight.

-Peter

[Grab]

Thank you both for your explanations, I will make some tests to see if it works well.

And thanks a lot for this great software!

Kind regards,
Ben