Gas Transport - CFX

kastarkas · July 5, 2018, 05:18

Hello all,
Problem : Transport of oxygen from Inlet towards outlet via a porous domain.
no of interfaces = 2 ; (inlet fluid-porous and porous-outlet fluid)

Kindly verify this methodology and suggest any corrections :
Setting partial pressure of O2 as additional variable (with diffusion) and adding a source term involving PO2 within the inlet subdomain. Planning to start with inlet BC's for PO2; but ..not sure about the BC's in porous and outlet domains.

THanks in Advance.
Wish you all health.

ghorrocks · July 5, 2018, 07:26

Is it all a single phase? That is, the oxygen is dissolved in the fluid and remains dissolved all the way through, it just diffuses and convects from the inlet to the outlet? If so, then the multicomponent mixture model was designed to model this type of flow, and should require no special treatment by source terms or anything like that.

kastarkas · July 5, 2018, 07:39

hello glenn,
It is all a single phase...I have seen the strategy as I said for modelling this problem...so what is the best option ?

ghorrocks · July 5, 2018, 07:40

Use a multicomponent mixture. So your oxygen concentration is a mass fraction, and requires no special handling at the inlet or porous regions. Instead you set the inlet O2 mass fraction and that's all.

kastarkas · July 7, 2018, 02:35

I will try that ...thanks a lot glenn

July 5, 2018, 05:18	Gas Transport - CFX	#1
kastarkas Member kastarkas Join Date: Aug 2016 Posts: 45 Rep Power: 9	Hello all, Problem : Transport of oxygen from Inlet towards outlet via a porous domain. no of interfaces = 2 ; (inlet fluid-porous and porous-outlet fluid) Kindly verify this methodology and suggest any corrections : Setting partial pressure of O2 as additional variable (with diffusion) and adding a source term involving PO2 within the inlet subdomain. Planning to start with inlet BC's for PO2; but ..not sure about the BC's in porous and outlet domains. THanks in Advance. Wish you all health.

July 5, 2018, 07:26		#2
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,703 Rep Power: 143	Is it all a single phase? That is, the oxygen is dissolved in the fluid and remains dissolved all the way through, it just diffuses and convects from the inlet to the outlet? If so, then the multicomponent mixture model was designed to model this type of flow, and should require no special treatment by source terms or anything like that. __________________ Note: I do not answer CFD questions by PM. CFD questions should be posted on the forum.

July 5, 2018, 07:40		#4
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,703 Rep Power: 143	Use a multicomponent mixture. So your oxygen concentration is a mass fraction, and requires no special handling at the inlet or porous regions. Instead you set the inlet O2 mass fraction and that's all. __________________ Note: I do not answer CFD questions by PM. CFD questions should be posted on the forum.

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Surface instabilities with 2-phase species transport	richard222	Fluent Multiphase	0	May 4, 2016 04:06
how can i model the ideal gas law in CFX?	CFX13	CFX	3	July 4, 2013 07:20
CFX Model for dispersion of gas through a porous media filled with Oil	deepmetal	CFX	13	November 27, 2010 20:34
Gas dissolution from liquid phase with CFX	Roger Young	CFX	2	May 6, 2008 07:37
CFX 4.4 installation problem	Pandu Sattvika	CFX	1	December 1, 2001 04:07

July 5, 2018, 07:39		#3
kastarkas Member kastarkas Join Date: Aug 2016 Posts: 45 Rep Power: 9	hello glenn, It is all a single phase...I have seen the strategy as I said for modelling this problem...so what is the best option ?

July 7, 2018, 02:35		#5
kastarkas Member kastarkas Join Date: Aug 2016 Posts: 45 Rep Power: 9	I will try that ...thanks a lot glenn