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

3D Multicomponent Model

Register Blogs Community New Posts Updated Threads Search

Like Tree6Likes
  • 1 Post By fresty
  • 1 Post By Opaque
  • 1 Post By Opaque
  • 1 Post By fresty
  • 2 Post By ghorrocks

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   December 18, 2014, 03:05
Default 3D Multicomponent Model
  #1
Member
 
Faizan
Join Date: Mar 2014
Posts: 76
Rep Power: 12
Mfaizan is on a distinguished road
Hi All,

I am developing a 3D multicomponent model in CFX. I am trying to couple two fluids nitrogen and air. I have defined the domains. The problem statement is such nitrogen is in a Nozzle and entering into the surrounding air domain. the surrounding air domain is a large room. Now my confusion is that how can I be sure that nozzle inside volume contains nitrogen fluid material and surrounding air domain contain air fluid material. Because when I see the material tab which shows both fluid in alphabetical order.

How can I check that I have inserted the right fluid material to right domain?????? anyone can help will be appreciated alot....
Mfaizan is offline   Reply With Quote

Old   December 18, 2014, 16:54
Default
  #2
Senior Member
 
Join Date: Aug 2014
Location: UK
Posts: 213
Rep Power: 13
fresty is on a distinguished road
Quote:
Originally Posted by Mfaizan View Post
Hi All,

I am developing a 3D multicomponent model in CFX. I am trying to couple two fluids nitrogen and air. I have defined the domains. The problem statement is such nitrogen is in a Nozzle and entering into the surrounding air domain. the surrounding air domain is a large room. Now my confusion is that how can I be sure that nozzle inside volume contains nitrogen fluid material and surrounding air domain contain air fluid material. Because when I see the material tab which shows both fluid in alphabetical order.

How can I check that I have inserted the right fluid material to right domain?????? anyone can help will be appreciated alot....
HI,

Trying to comprehend your question, domain material selection is only executed after selecting a particular meshed region which i presume you must have, so i do not see how you would be unsure of the selection.
Can you please, post some rough sketch or some sort of reference to look at, to understand the issue here.

Thanks.

P.S. http://www.cfd-online.com/Forums/cfx...ease-read.html
Mfaizan likes this.
fresty is offline   Reply With Quote

Old   December 18, 2014, 19:56
Default
  #3
Member
 
Faizan
Join Date: Mar 2014
Posts: 76
Rep Power: 12
Mfaizan is on a distinguished road
Attachment 36102

HPGas Nitrogen.jpg

Hi fresty,

Thanks for response- I have attached pics of Air domain and HPgas which is nozzle inside domain having nitrogen. Now if you can see at material tab, there is no change of assigned material when changing domains. Both air and hpgas domain showing N2 material as first material.

I have this confusion as if have correctly assigned the correct material to correct mesh regions....Please suggest..

Thanks

Last edited by Mfaizan; December 17, 2015 at 23:46.
Mfaizan is offline   Reply With Quote

Old   December 18, 2014, 22:16
Default
  #4
Senior Member
 
Join Date: Jun 2009
Posts: 1,880
Rep Power: 33
Opaque will become famous soon enough
Not exactly sure what you are trying to model; however, if you are trying to model a mixture of gases you are approaching it the wrong way. It seems you are setting up the problem as a CFX multiphase simulation.

Have you reviewed the tutorials for mixing "CFX materials" (not "CFX phases")? If you follow those tutorials you may save considerable time and frustrations.
Mfaizan likes this.
Opaque is offline   Reply With Quote

Old   December 18, 2014, 23:22
Default
  #5
Member
 
Faizan
Join Date: Mar 2014
Posts: 76
Rep Power: 12
Mfaizan is on a distinguished road
Hi Opaque,

You are absolutely RIGHT. I am trying to mix two fluids one is nitrogen inside the nozzle with inlet conditions as 14 bar total pressure and 550C total temperature. The other fluid is surrounding air which is at ambient temperature and pressure. It is a mixture CFX model and it is not a multiphase model.

I have been reading cfx documentation but I am unable to setup the case. I also searched tutorial but its all referring to multiphase. I need a multicomponent tutorial. Please suggest me a link or any reference where I can get some help.

Many many thanks in advance.
Mfaizan is offline   Reply With Quote

Old   December 19, 2014, 01:40
Default
  #6
Senior Member
 
Join Date: Jun 2009
Posts: 1,880
Rep Power: 33
Opaque will become famous soon enough
You can refer to the following tutorials:

"Reacting Flow in a Mixing Tube"

"Combustion and Radiation in a Can Combustor"

"Steam Jet" (this is a multicomponent-multiphase tutorial"

You must create the mixture material before you attempt to associate domains to meshes, and material to phases.
Mfaizan likes this.
Opaque is offline   Reply With Quote

Old   December 19, 2014, 01:47
Smile
  #7
Member
 
Faizan
Join Date: Mar 2014
Posts: 76
Rep Power: 12
Mfaizan is on a distinguished road
Thanks Opaque indeed.

Actually I have one confusion that if I defined the material as mixture initially then how can I get the physics of two fluids?

As I mentioned that nitrogen is at 14bar pressure and 550C while air is a surrounding/room fluid with ambient condition like 1 atm pressure and 25C temp?

please suggest...

Many thanks
Mfaizan is offline   Reply With Quote

Old   December 19, 2014, 03:39
Default
  #8
Senior Member
 
Join Date: Aug 2014
Location: UK
Posts: 213
Rep Power: 13
fresty is on a distinguished road
Agree with Opaque on the comments of using mixture of fluids as the right approach. Multiphase per my humble understanding deals with a domain with existing multiple fluids (vapors, mist etc.).
If you go through the tutorials suggested by Opaque you would get most of the answers to your questions/ confusion.
Domain initial conditions in a fluid mixing model can be different and do not affect until the flow domains from both mesh regions interact/ are interfaced, which i presume you will define (inlet and outlet of nozzle).

Thanks.
Mfaizan likes this.
fresty is offline   Reply With Quote

Old   December 19, 2014, 05:13
Default
  #9
Super Moderator
 
Glenn Horrocks
Join Date: Mar 2009
Location: Sydney, Australia
Posts: 17,871
Rep Power: 144
ghorrocks is just really niceghorrocks is just really niceghorrocks is just really niceghorrocks is just really nice
The CFX documentation has a much better definition of the difference between multicomponent and multiphase:

Quote:
Multiphase flow refers to the situation where more than one fluid is present. Each fluid may possess its own flow field, or all fluids may share a common flow field. Unlike multicomponent flow, the fluids are not mixed on a microscopic scale in multiphase flow. Rather, they are mixed on a macroscopic scale, with a discernible interface between the fluids. ANSYS CFX includes a variety of multiphase models to allow the simulation of multiple fluid streams, bubbles, droplets, solid particles, and free surface flows.
Mfaizan and fresty like this.
ghorrocks is offline   Reply With Quote

Old   August 18, 2020, 06:32
Default Multicomponent multiphase flow
  #10
New Member
 
Lucky Elechi
Join Date: May 2020
Location: Port Harcourt, Nigeria
Posts: 9
Rep Power: 6
Elechi is on a distinguished road
I have a homogeneous binary mixture of saltwater material and water vapor, Is it possible for me to use this homogeneous binary mixture as a liquid component in a multiphase flow?

What I find hard to understand is if the homogeneous binary mixture material is also a multicomponent material. If it can be used, how do I setup a multicomponent multiphase flow model in Ansys cfx? Thank you.
Elechi is offline   Reply With Quote

Reply


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
manualInjection model in sprayFoam Mentalo OpenFOAM Running, Solving & CFD 1 April 2, 2014 10:29
Mixture model + VOF? blacksoil2012 Fluent Multiphase 2 February 9, 2014 00:59
Water subcooled boiling Attesz CFX 7 January 5, 2013 04:32
Problems bout CFD model of biomass gasification, Downdraft gasifier wanglong FLUENT 2 November 26, 2009 00:27
Advanced Turbulence Modeling in Fluent, Realizable k-epsilon Model Jonas Larsson FLUENT 5 March 13, 2000 04:27


All times are GMT -4. The time now is 21:33.