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

Simulation is deverging

Register Blogs Community New Posts Updated Threads Search

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   August 16, 2017, 10:43
Default Simulation is deverging
  #1
FFD
Member
 
Join Date: Aug 2015
Posts: 30
Rep Power: 11
FFD is on a distinguished road
Hello,
My simulation is deverges after 1 step. The AMG solver deverges. I guess the problem is my assumption for the turbulence.
I often get also the message that my turbulence viscosity is limited on many cells and that I have a reversed flow in some faces on pressure-outlet.

I use the k-omega approach.
My fluid flows in a helix. 2 meters long with a diameter of 55mm and 30 revolutions. So I calculated the length of my fluid area, which would be when I would have a straight line instead of the helix. My value was about 5.55m.
With water as fluid and 1m/s free stream velocity I calculated my tke(0.0007917900792802) and sdr(0.0000038681421927). My simulation still deverges pretty fast. After 1 iteration I get the error message that the AMG solver for temperature doesn't converges.

My models are:
Energy equations - on
Viscous model - k-omega standard
rest is default
My inlet is a velocity inlet with 1m/s and the given tke and sdr
My outlet is a pressure outlet with 0pa and the given tke and sdr
My solution methods are not clear now. I tied it with all best approaches (like 3rd Order stuff) and standard methods. Always the same results.
Solution controls are standard.
Solution initialization is standard with my values taken from the inlet.

Any suggestions?

Best regards FFD
FFD is offline   Reply With Quote

Reply

Tags
divergence amg


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
Surface Source - Fixed Temperature? robtheslob FloEFD, FloWorks & FloTHERM 18 May 12, 2017 03:28
Simulation FPEs - turbulence for transient and steady-state? DaveR OpenFOAM Running, Solving & CFD 5 March 5, 2017 16:06
Waterbell Simulation o.b.m Fluent Multiphase 1 November 5, 2015 06:55
setting up a simulation with multiple interactions phandy OpenFOAM Running, Solving & CFD 1 October 6, 2014 04:16
Continuous vs interrupted simulation sega OpenFOAM Running, Solving & CFD 4 November 3, 2008 15:29


All times are GMT -4. The time now is 16:28.