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

Simulating a Supersonic Diffuser

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

LinkBack Thread Tools Search this Thread Display Modes
Old   December 24, 2014, 01:33
Post Simulating a Supersonic Diffuser
New Member
Hossein Noorsalehi
Join Date: Dec 2014
Posts: 2
Rep Power: 0
noorsalehi is on a distinguished road
Hi All,
I have tried to simulate an inviscid supersonic diffuser in CFX. The inlet boundary conditions are: mach number=3 , Total Pressure is 70000 pa & Total Temperature=300 K. I expect to have a normal shock in the throat or in the beginning of the diverging zone of the diffuser. Therefore the outlet flow regime must be subsonic.
In order to simulate an inviscid flow regime, the viscosity of the Air Ideal Gas is put to 1E-15 pa.s , the flow regime is laminar and the wall condition is free slip.
I have tested various back pressures at the outlet, but the normal shock has brought back to the converging zone and its position is not stable, so the solution will not be converged.

Is CFX a reliable software to simulate such internal regimes? If so, would you please help me solving this problem?
noorsalehi is offline   Reply With Quote

Old   December 25, 2014, 03:43
Super Moderator
Glenn Horrocks
Join Date: Mar 2009
Location: Sydney, Australia
Posts: 17,695
Rep Power: 143
ghorrocks is just really niceghorrocks is just really niceghorrocks is just really niceghorrocks is just really nice
Yes, CFX should be able to model this.

Have you checked your boundary conditions are correct? Have you done a mesh sensitivity check? Also convergence criteria, time step size (if relevant) and boundary proximity?

This FAQ has more comments:
ghorrocks is offline   Reply With Quote

Old   November 23, 2022, 13:32
New Member
Join Date: Dec 2012
Posts: 8
Rep Power: 13
samane_81 is on a distinguished road
Hi Noorsalehi,
could you solve your problem?
Why didn't you use a pressure inlet?
samane_81 is offline   Reply With Quote


invicid, normal shock, supersonic diffuser

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
[How to obtain supersonic flow inside a supersonic wind tunnel ?] yx213 Siemens 1 September 17, 2014 13:52
Need help defining a momentum source for a diffuser inlet serezhkin CFX 1 April 2, 2013 12:20
Supersonic Inlet for a Compressible Flow in a Nozzle Daco FLUENT 8 November 8, 2012 03:34
Probelm with supersonic exhaust to ambient newj CFX 2 August 9, 2012 18:01
Simulating a Supersonic Diffuser-Need Help Dileep Main CFD Forum 1 April 18, 2002 06:25

All times are GMT -4. The time now is 21:12.