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

Problems with an overexpanded nozzle simulation

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

LinkBack Thread Tools Search this Thread Display Modes
Old   April 11, 2015, 07:01
Default Problems with an overexpanded nozzle simulation
New Member
Join Date: Apr 2014
Posts: 1
Rep Power: 0
nmtr is on a distinguished road
Hey everyone!

I'm trying to do a validation of a rocket nozzle simulation (data from this paper), currently on the 21 NPR case, but ran into some difficulties.
The simulation does not really want to converge even with first order discretisation as continuity and energy RMS oscillates around 1e-2. There is also a "turbulent viscosity limited to..." in each iteration and a reversed flow on outlet message. The cap shock position and flowfield shape seems right, y+ on the nozzle contour is below 0.5.

The model is a ~120k unstructured mesh, the problem is axisymmetric, the turbulence model is SST, boundaries: pressure-inlet at nozzle, pressure-inlet at the front of the outer area, pressure-outlet at the rear, axis on the bottom and free-slip wall on top. I attempted both first-and second order discretisations, results are similar.

I'd really appreciate some feedback

Pictures say more than words:
mesh.jpg flow.jpgRMS.pngbackflow.jpgtkrlimited.png
nmtr is offline   Reply With Quote


nozzle simulation, sst k-omega, unstructured mesh

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
[rhoCentralFoam] Crash in Nozzle Simulation maxmax OpenFOAM Running, Solving & CFD 6 June 3, 2015 15:51
Need help with a rocket nozzle simulation badboyz31 CFX 14 September 22, 2014 00:06
Supersonic Nozzle Exhaust Simulation mikeh FLUENT 0 May 1, 2014 21:28
Need assistance in BC's for simulation of Vacuum cleaning nozzle bruce OpenFOAM Running, Solving & CFD 0 May 22, 2009 13:56
Problems on H2/air CFX simulation xulixian OpenFOAM Running, Solving & CFD 2 April 14, 2009 15:00

All times are GMT -4. The time now is 17:47.