Menu

Discussion Forum

New Discussion
Filter

Discussion Closed This discussion was created more than 6 months ago and has been closed. To start a new discussion with a link back to this one, click here.

Comsol asking for Ratio of Specific Heats for solid.

Posted Feb 1, 2017, 8:48 a.m. EST Heat Transfer & Phase Change, Materials, Modeling Tools & Definitions, Parameters, Variables, & Functions Version 5.2 4 Replies

Anthony Lethuillier
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Hello,

I am trying to build a simple model that finds the temperature as a function of time.


The model is part gas / part solid I therefore used the Heat Trasnfer in Fluids physics and I defined the gas and solid parts.

When assigning material properties I use the materials defined in the database but it asks me to fill in the Ratio of Specific Heats for all materials (solid and gases).

According to en.wikipedia.org/wiki/Heat_capacity_ratio this is possible for gases but not for solids.

Am i doing something wrong or is it my understanding of the physics that are wrong ?

Thanks in advance for any help,

I've attached the model I'm working on.

4 Replies Last Post Mar 12, 2017, 7:29 a.m. EDT
townbiscuit
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Posted: 8 years ago Feb 3, 2017, 10:57 a.m. EST
Hey Anthony,

I`m still getting used with Comsol, but from my experience, this can happen if you define your physics wrong and you set up a study intended for a gas to a solid.. which could explain why Comsol is asking for the ratio of specific heats. Someone more experienced should confirm this though.
Hey Anthony, I`m still getting used with Comsol, but from my experience, this can happen if you define your physics wrong and you set up a study intended for a gas to a solid.. which could explain why Comsol is asking for the ratio of specific heats. Someone more experienced should confirm this though.
Lay Sotheary
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Posted: 8 years ago Mar 11, 2017, 2:53 a.m. EST
Hi
Did you find this solution? I also met this problem. If you found this solution, please you kindly let me know.

Thank you,
Theary
Hi Did you find this solution? I also met this problem. If you found this solution, please you kindly let me know. Thank you, Theary
Lasse Murtomäki
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Posted: 8 years ago Mar 11, 2017, 5:37 a.m. EST
For solids the ratio is 1.

For gases: Cp - Cv = R

Hence: Cv/Cp = 1 - R/Cp

Ideal gas law applies surprisingly well even at elevated temperatures and pressures.

Lasse
For solids the ratio is 1. For gases: Cp - Cv = R Hence: Cv/Cp = 1 - R/Cp Ideal gas law applies surprisingly well even at elevated temperatures and pressures. Lasse
Lay Sotheary
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Posted: 8 years ago Mar 12, 2017, 7:29 a.m. EDT
Thank you, Lasse Murtomäki for your replying.
Thank you, Lasse Murtomäki for your replying.

Note that while COMSOL employees may participate in the discussion forum, COMSOL® software users who are on-subscription should submit their questions via the Support Center for a more comprehensive response from the Technical Support team.

Suggested Content