CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > Software User Forums > ANSYS > CFX

Necessary Properties for heat transfer

Register Blogs Members List Search Today's Posts Mark Forums Read

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   January 7, 2020, 21:09
Post Necessary Properties for heat transfer
  #1
M29
New Member
 
Sumin Park
Join Date: Jul 2019
Posts: 26
Rep Power: 3
M29 is on a distinguished road
Hello!

I use CFX to simulate heat transfer in dry cask.

To put it simply, I want to simulate heat transfer between solid and fluid domain.

I will use ideal helium gas in fluid domain and carbon steel and stainless steel in solid domain.

But I know only density, thermal conductivity, thermal expansion coefficient, and specific heat for carbon and stainless steel.

E.g. I don't know molar mass, Ref. specific enthalpy and so on.. in cfx property tap.

So, i want to know the necessary properties to simulate heat transfer between solid and fluid domain...
M29 is offline   Reply With Quote

Old   January 8, 2020, 02:51
Default
  #2
Senior Member
 
Gert-Jan
Join Date: Oct 2012
Posts: 1,155
Rep Power: 17
Gert-Jan is on a distinguished road
Molar mass is only relevant for Helium since the density is derived from it. For steel, density is fixed. You don't have worry about Enthalpies. For most cases, these are irrelevant. Set them to 0.
Gert-Jan is offline   Reply With Quote

Old   January 8, 2020, 11:25
Default
  #3
M29
New Member
 
Sumin Park
Join Date: Jul 2019
Posts: 26
Rep Power: 3
M29 is on a distinguished road
Quote:
Originally Posted by Gert-Jan View Post
Molar mass is only relevant for Helium since the density is derived from it. For steel, density is fixed. You don't have worry about Enthalpies. For most cases, these are irrelevant. Set them to 0.
First of all, thank you for your answer.

Can i ask something about your answer?

If the steel density is the function of temperature, is it no matter??

And, do you know when the enthalpies use?
M29 is offline   Reply With Quote

Old   January 8, 2020, 13:21
Default
  #4
Senior Member
 
Gert-Jan
Join Date: Oct 2012
Posts: 1,155
Rep Power: 17
Gert-Jan is on a distinguished road
If you have density function that depends on temperature, then it depends on temperature. Not on molar mass.
Enthalpy is just a reference state from which temperatures are derived.

If you don't trust it, just do a test where you change the parameters and see what you get.
Gert-Jan is offline   Reply With Quote

Old   January 8, 2020, 13:33
Default
  #5
Senior Member
 
Erik
Join Date: Feb 2011
Location: Earth (Land portion)
Posts: 966
Rep Power: 18
evcelica is on a distinguished road
Density should be constant to account for all solid mass, unless you are modeling the change in size as part of the analysis, which I'm sure you are not, as this would then be a 2 way FSI.

If this is steady state then density and specific heat won't matter for solid domains, they only effect transient results.
evcelica is offline   Reply With Quote

Old   January 13, 2020, 02:11
Default
  #6
M29
New Member
 
Sumin Park
Join Date: Jul 2019
Posts: 26
Rep Power: 3
M29 is on a distinguished road
Quote:
Originally Posted by Gert-Jan View Post
If you have density function that depends on temperature, then it depends on temperature. Not on molar mass.
Enthalpy is just a reference state from which temperatures are derived.

If you don't trust it, just do a test where you change the parameters and see what you get.
Thank you!! I will try that.
M29 is offline   Reply With Quote

Old   January 13, 2020, 02:16
Default
  #7
M29
New Member
 
Sumin Park
Join Date: Jul 2019
Posts: 26
Rep Power: 3
M29 is on a distinguished road
Quote:
Originally Posted by evcelica View Post
Density should be constant to account for all solid mass, unless you are modeling the change in size as part of the analysis, which I'm sure you are not, as this would then be a 2 way FSI.

If this is steady state then density and specific heat won't matter for solid domains, they only effect transient results.
I can't understand exactly.. but density and specific heat in solid are not necessary to simulate heat transfer between solid and fluid domain, aren't you?
M29 is offline   Reply With Quote

Old   January 13, 2020, 04:15
Default
  #8
Senior Member
 
Gert-Jan
Join Date: Oct 2012
Posts: 1,155
Rep Power: 17
Gert-Jan is on a distinguished road
It all depends on: "What question are you trying to answer using CFD?".
Please answer this.

If you don't need to know the temperature in the solid, then you don't need these properties. If you need to include the temperature distribution in the solid, then you need to provide density and specific heat. But probably not as a function of whatsoever. If your temperature range is limited, then their influence will be limited.

Again, it all comes doen to the questions: "What question are you trying to answer using CFD?". You need to know for your self what you can ignore, and what not. We at this forum don't know if you are not clear about the EXACT problem you are trying to solve.
Gert-Jan is offline   Reply With Quote

Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Radiation in semi-transparent media with surface-to-surface model? mpeppels CFX 11 August 22, 2019 07:30
Domain Reference Pressure and mass flow inlet boundary AdidaKK CFX 75 August 20, 2018 05:37
Mass Transfer oliveira1820 CFX 11 June 26, 2018 02:54
Convective / Conductive Heat Transfer in Hypersonic flows enigma Main CFD Forum 2 November 1, 2009 22:53
Convective Heat Transfer - Heat Exchanger Mark CFX 6 November 15, 2004 15:55


All times are GMT -4. The time now is 02:32.