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

Turbulence Model in axisymmetric nozzle simulation

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

Like Tree2Likes
  • 2 Post By Arjun_kalkur

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   May 21, 2013, 03:03
Default Turbulence Model in axisymmetric nozzle simulation
  #1
New Member
 
Join Date: Dec 2012
Posts: 11
Rep Power: 13
cric92 is on a distinguished road
Hi

I am simulating an axisymmetric nozzle. I have an issue with which turbulence model to use. Currently I am using standard K-epsilon and i am not getting any shock wave inside the nozzle. When I switch to SST K omega i get shock wave in the flow.

I would like to ask which is the recommended turbulence model for these type of flow
cric92 is offline   Reply With Quote

Old   May 21, 2013, 06:27
Default
  #2
Senior Member
 
OJ
Join Date: Apr 2012
Location: United Kindom
Posts: 473
Rep Power: 19
oj.bulmer will become famous soon enough
By intuition, std k-eps model is diffusive and hence may smear out the sharp gradients responsible for shocks. Have you tried realizable model? It is deemed to be good in modelling jets.

OJ
oj.bulmer is offline   Reply With Quote

Old   May 22, 2013, 12:50
Default
  #3
New Member
 
Join Date: Dec 2012
Posts: 11
Rep Power: 13
cric92 is on a distinguished road
Yes, Just tried realizable.. it also shows a shock wave
cric92 is offline   Reply With Quote

Old   September 4, 2017, 13:11
Default
  #4
New Member
 
Jeff Yam
Join Date: Sep 2017
Posts: 11
Rep Power: 8
NozzleNoobie is on a distinguished road
Hi, could i ask you what do you mean by diffusive?
NozzleNoobie is offline   Reply With Quote

Old   September 4, 2017, 17:57
Default
  #5
New Member
 
Arjun Kalkur
Join Date: Sep 2017
Posts: 12
Rep Power: 8
Arjun_kalkur is on a distinguished road
K-epsilon does not behave well in large pressure gradient, one like shocks, I'd suggest to stick with SST. By diffusive he means the behavior of the solver, like for eg:- Picks the information from the succeeding nodes and moves forward
NozzleNoobie and TommyM like this.
Arjun_kalkur is offline   Reply With Quote

Old   September 5, 2017, 00:35
Default
  #6
New Member
 
Jeff Yam
Join Date: Sep 2017
Posts: 11
Rep Power: 8
NozzleNoobie is on a distinguished road
I see that the SST k-omega model is more suitable for compressible flow into a nozzle for its good behaviour in adverse pressure gradients (shock) and separating flow. Thank you for your help!
NozzleNoobie is offline   Reply With Quote

Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

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
Modified k-e turbulence model UDF Travis Fluent UDF and Scheme Programming 7 November 11, 2018 21:21
Difficulty in calculating angular velocity of Savonius turbine simulation alfaruk CFX 14 March 17, 2017 07:08
An error has occurred in cfx5solve: volo87 CFX 5 June 14, 2013 18:44
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 09:23.