CFD Online Logo CFD Online URL
Home > Forums > Software User Forums > ANSYS > CFX

Convergent Divergent Nozzle with Separation

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

LinkBack Thread Tools Search this Thread Display Modes
Old   January 31, 2011, 17:12
Default Convergent Divergent Nozzle with Separation
New Member
Ozan Kalkan
Join Date: Mar 2010
Posts: 1
Rep Power: 0
ookalkan is on a distinguished road
Hi everyone,

I am trying simulate the fluid flow and heat transfer in a convergent divergent nozzle in both Fluent and CFX. My aim is to validate the codes by comparing the results with an experiment.

I got satisfactory results by Fluent, however I have some problems with CFX. Here is the problem:

In this case, nozzle inlet total pressure is 75.2 psia, inlet total temperature is 843K and exit Mach number is 2.5. At that pressure, it is indicated by the experiment that there is a flow separation at the nozzle outlet. But, if I specify the outlet boundary condition as "Supersonic Outlet", CFX does not allow reversed flow, i.e. separation. Therefore, i have used "Opening" boundary condition at the outlet in order to let the flow turn back. This time I see quite weird temperature contours near the outlet. Temperature drops upstream of the throat,as supposed, but then it increases again near the outlet. I am suspicious that this is because of the "Opening Temperature" specification. But I am not sure.

So I wonder how can I simulate the separation near the nozzle outlet in CFX?
Which boundary condition should I use for outlet?

Best regards,
ookalkan is offline   Reply With Quote


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
Convergent Divergent Nozzle Hrishikesh Main CFD Forum 12 June 25, 2016 02:06
convergent_divergent nozzle simulation in CFX-11 sivarama1 CFX 22 February 18, 2013 16:23
Convergent divergent nozzle csmistry CFX 6 September 16, 2009 01:40
compressible flow in a counterflow nozzle d.vamsidhar FLUENT 0 November 24, 2005 01:45
Meshing divergent nozzle entry of a long pipe Aly FLUENT 1 September 25, 2005 17:07

All times are GMT -4. The time now is 04:16.