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 May 17, 2013, 07:20 Radiation #21 New Member   Abdalla Join Date: May 2013 Posts: 4 Rep Power: 6 Dear topsedar, I am simulating the same case and i don't know how to design the vacuum between two solids where only heat radiation occurs. Did you assume it is as solid and what are the material properties? or is there another way to setup the vacuum? I really appreciate your help. Thank you.

 May 17, 2013, 07:30 #22 Super Moderator   Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 13,437 Rep Power: 104 My posts tell you exactly how to do it. Model it as a transparent solid with an almost zero thermal conductivity.

May 17, 2013, 07:49
#23
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Abdalla
Join Date: May 2013
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Dear ghorrocks, how can i make the solid transparent and what are the suggested values of the solid material properties as shown in the attachment. I appreciate your help and thank you
Attached Images
 CFD.jpg (93.6 KB, 14 views)

 May 17, 2013, 09:20 #24 Super Moderator   Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 13,437 Rep Power: 104 The tab you are showing is for a fluid. You need to make it a solid. In the radiation properties make absorption coeff=0. Now it does not absorb, that is it is transparent.

May 17, 2013, 09:38
#25
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Abdalla
Join Date: May 2013
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This photo is for the material properties which its thermodynamic state is chosen to be solid. It solid domain will be chosen when applying boundary condition as shown in the attached photo "CFD2.jpg". If I am still doing it wrong please tell me what is the correct way. Otherwise will you please give me the best properties approximation that represents the vacuum material as shown in the first attached "CFD.jpg". In term of "Molar mass, Density, Specific heay capacity, Ref. Spec. Enthalpy, Entropy, Dynamic Viscosity, Thermal Conductivity, Refractive Index, Absorption Coefficient, Scattering Coefficient, Thermal Expansivity"
Attached Images
 CFD.jpg (93.6 KB, 7 views) CFD2.jpg (56.8 KB, 7 views)

 May 17, 2013, 14:10 #26 New Member   Abdalla Join Date: May 2013 Posts: 4 Rep Power: 6 Will you please look into my question? The submission is soon and I need to be done with it. Thank you

 May 17, 2013, 19:12 #27 Super Moderator   Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 13,437 Rep Power: 104 Almost all of those parameters are irrelevant. Some require values just to keep the solver happy. I will leave it as an exercise for you to work this out. If you are not sure whether a parameter is important or not then do a sensitivity check (run a value then 10x the value and see if it makes a difference) to find out. And just a comment - do not rush people on a free open forum like this. If you are in a hurry you should pay for support from ANSYS. On a free forum you get help when we get around to it.

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