# mixing quality simulation

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

 March 11, 2009, 02:57 mixing quality simulation #1 harry Guest   Posts: n/a Hello All, I'm involved in a simulation addressing the mixing quality between two kinds of liquids in a micromixer. Dimensionless parameter α was defined with the maximum standard deviation to describe the mixing quality between species along a cross section:α=1âˆ' sqrt(σ2M/σ2max), where σ2max is the maximum variance of the species and σ2M is the mean square deviation of concentration field: and cM is the mean concentration distribution of the species i over n elements of the mesh in a certain cross section of the mixing channel, my question is how to achieve this using CFX? Thanks for your help.

 March 11, 2009, 11:49 Re: mixing quality simulation #2 harry Guest   Posts: n/a Dear all, is there anyone who could help me? Take T-shape mixer as an example, two different fluids come inside the mixer from two inlets , flow along a mixing channel after junction and get out from one common outlet,I need to figure out the mixing efficiency in the correspondently different cross section of the mixing channel, and this mixing efficiency is based on the concentration distribution on that cross section. This requires to calculate average concentration of that cross section , but to do this, you need to know the specific concentration value of some sampling points on this section, my question is how I can define these points and their concentration? And how should I setup these parameters in CFX? Do I need to create a new variable called concentration in the software? Thanks a lot.

 March 11, 2009, 22:26 Re: mixing quality simulation #3 Glenn Horrocks Guest   Posts: n/a Hi, You should be able to do this in CEL, using the volumeInt() and areaInt() functions. Regards, Glenn

 March 12, 2009, 04:34 Re: mixing quality simulation #4 harry Guest   Posts: n/a Hello Glenn, Thank you very much for your prompt reply. I noticed we can also use Danckwerts' intensity of segregation(Danckwerts, 1952) to define the mixing efficiency, IS =σ^2/σmax^2,with σ^2 =volumeInt[(C-¯c)^2]/|V| where where ¯c denotes the mean value of the concentration field c and σmax^2 is a reference value. You did grant me a direction to approach this, sine I'm a new comer to touch with CFX, could you please specify it in detailed, like, how to express the above definition with CEL expression? Thanks for your help in advance. Best Wishes Harry

 March 12, 2009, 17:24 Re: mixing quality simulation #5 Glenn Horrocks Guest   Posts: n/a Hi, Sorry, don't have time to work it all out for you. Just work through it one step at a time and you will get there. ¯c might come from something like volumeAve(Variable Name)@Location. Look in the CEL Expression guide in the Reference manual for details of variable names. Glenn Horrocks

May 8, 2010, 14:36
intensity of mixing
#6
New Member

sai ram
Join Date: Sep 2009
Posts: 18
Rep Power: 9
Quote:
 Originally Posted by harry ;92314 Hello Glenn, Thank you very much for your prompt reply. I noticed we can also use Danckwerts' intensity of segregation(Danckwerts, 1952) to define the mixing efficiency, IS =σ^2/σmax^2,with σ^2 =volumeInt[(C-¯c)^2]/|V| where where ¯c denotes the mean value of the concentration field c and σmax^2 is a reference value. You did grant me a direction to approach this, sine I'm a new comer to touch with CFX, could you please specify it in detailed, like, how to express the above definition with CEL expression? Thanks for your help in advance. Best Wishes Harry
hii harry

i have the same problem like u. can you help me in finding the intensity of mixing please it would be really helpfull dude

 Thread Tools Display Modes Linear Mode

 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 OffTrackbacks are On Pingbacks are On Refbacks are On Forum Rules

 Similar Threads Thread Thread Starter Forum Replies Last Post fan123 Main CFD Forum 2 April 23, 2011 08:22 Smagmon CFX 1 March 6, 2009 14:24 sega OpenFOAM Running, Solving & CFD 4 November 3, 2008 15:29 fadhil FLUENT 0 August 24, 2008 22:11 DHKK Main CFD Forum 5 May 27, 2001 15:21

All times are GMT -4. The time now is 22:20.