Air properties

njssdfu · September 30, 2010, 10:03

Hello,
I read from previous posts that if I'm using AIR AT 25, density of air doesn't change with temperature. If it is true, my question is how to define it in material library.
Thank you for advice.

ghorrocks · September 30, 2010, 18:21

Have a look in the tutorials for examples. Any compressible flow example would show how to do it.

njssdfu · October 5, 2010, 03:34

I was looking into a lot of tutorials but I haven't found anything yet. But I tried to create my own air with defining the air density according to temperature but I have a big scale of temperature. Range from 20 - 800 degrees. Should I do it manually with step 1°C or could I do it some other way. And what about other properties of air when I'm simulating fire. Do I need them? Thank you for your help.

stumpy · October 5, 2010, 09:28

Use "Air Ideal Gas". Lots of the tutorials use this.

September 30, 2010, 10:03	Air properties	#1
njssdfu New Member Tom Join Date: Sep 2010 Posts: 4 Rep Power: 15	Hello, I read from previous posts that if I'm using AIR AT 25, density of air doesn't change with temperature. If it is true, my question is how to define it in material library. Thank you for advice.

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
mass flow in is not equal to mass flow out	saii	CFX	12	March 19, 2018 05:21
Constant velocity of the material	Sas	CFX	15	July 13, 2010 08:56
air bubble is disappear increasing time using vof	xujjun	CFX	9	June 9, 2009 07:59
Properties of air versus temperature AND pressure	Vincent	Main CFD Forum	5	July 28, 2008 06:28
Natural convection. Air properties	Cristina	FLUENT	3	March 24, 2007 08:23

September 30, 2010, 18:21		#2
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,703 Rep Power: 143	Have a look in the tutorials for examples. Any compressible flow example would show how to do it.

October 5, 2010, 03:34		#3
njssdfu New Member Tom Join Date: Sep 2010 Posts: 4 Rep Power: 15	I was looking into a lot of tutorials but I haven't found anything yet. But I tried to create my own air with defining the air density according to temperature but I have a big scale of temperature. Range from 20 - 800 degrees. Should I do it manually with step 1°C or could I do it some other way. And what about other properties of air when I'm simulating fire. Do I need them? Thank you for your help.

October 5, 2010, 09:28		#4
stumpy Senior Member Join Date: Apr 2009 Posts: 531 Rep Power: 21	Use "Air Ideal Gas". Lots of the tutorials use this.