How can define different diffusion coefficients

FrankW · April 21, 2010, 10:24

Hi,

i will solve a fluidsystem (Water) with an porous domain. To simulate Oxygen transport in this system i use an Additional Variable. My problem is i can't define different diffusion coefficients in different domains. If i change in one domain the diffusion coeff. than is this cofficient in the other domain the same. What do i wrong or is't such possible.

best regards
Frank

gypas · July 31, 2010, 10:43

Don't know if you solved your problem yet there is a way of disabling constant physics in domains, actually there are a couple of threads describing how
http://www.cfd-online.com/Forums/cfx...s-cfx-pre.html
http://www.cfd-online.com/Forums/cfx...nt-domain.html
However, when I used this method the solver was very unstable and did not get accurate solutions.
Depending on the problem you are trying to model, you might be better off by assigning different fluids, values to different domains setting user parameters
for instance
domain 1 = domain1
domain 2 = domain2
fluid name1 = Water
fluid name2 = Vapor
but have not tried that myself
i only used user parameters in single flow simulation
I will be going back to multiphase domains later this year (beginning of November to be exact) and will discuss it in length with my support.
If by then you haven't sort it things out you are more than welcome to email me and I will give you further details.

April 21, 2010, 10:24	How can define different diffusion coefficients	#1
FrankW Member Frank Weise Join Date: Mar 2009 Location: Germany Posts: 55 Rep Power: 17	Hi, i will solve a fluidsystem (Water) with an porous domain. To simulate Oxygen transport in this system i use an Additional Variable. My problem is i can't define different diffusion coefficients in different domains. If i change in one domain the diffusion coeff. than is this cofficient in the other domain the same. What do i wrong or is't such possible. best regards Frank

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Moving mesh	Niklas Wikstrom (Wikstrom)	OpenFOAM Running, Solving & CFD	122	June 15, 2014 07:20
Installing OF 1.6 on Mac OS X	gschaider	OpenFOAM Installation	129	June 19, 2010 10:23
Missing math.h header	Travis	FLUENT	4	January 15, 2009 12:48
Free surface boudary conditions with SOLA-VOF	Fan	Main CFD Forum	10	September 9, 2006 13:24
UDF FOR UNSTEADY TIME STEP	mayur	FLUENT	3	August 9, 2006 11:19

July 31, 2010, 10:43		#2
gypas New Member catherina Join Date: May 2009 Posts: 7 Rep Power: 17	Don't know if you solved your problem yet there is a way of disabling constant physics in domains, actually there are a couple of threads describing how http://www.cfd-online.com/Forums/cfx...s-cfx-pre.html http://www.cfd-online.com/Forums/cfx...nt-domain.html However, when I used this method the solver was very unstable and did not get accurate solutions. Depending on the problem you are trying to model, you might be better off by assigning different fluids, values to different domains setting user parameters for instance domain 1 = domain1 domain 2 = domain2 fluid name1 = Water fluid name2 = Vapor but have not tried that myself i only used user parameters in single flow simulation I will be going back to multiphase domains later this year (beginning of November to be exact) and will discuss it in length with my support. If by then you haven't sort it things out you are more than welcome to email me and I will give you further details.