CFD Online Logo CFD Online URL
Home > Forums > CD-adapco

1D3D GT coupling :intake manifold convergence prob

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

LinkBack Thread Tools Display Modes
Old   June 16, 2008, 09:35
Default 1D3D GT coupling :intake manifold convergence prob
Posts: n/a
Hello, everyone

I'm trying to run a Star-CD/GT-Power coupled model of a 4 cyl intake manifold at 2000rpm, but I can't make it converge. I've gone as far as lower the timestep to 1.7E-08s (=0.02 CA; anything above 0.05 CA trigger the "negative dentsities" more or less quickly) to get rid of the "negative densities found" problem, but even then, my results show, sorry for the word, shit: temperature is dropping to 250K and speed at the outlet tops at 140m/s. No sign of pressure oscillations, speed and temperature seems to, respectively, increase and decrease gradually.The inlet transforms into an outlet after a few timesteps , and air is flowing out of it and the other 3 supposedly closed intake valves. The courant number is low, very low (max<<1, mean<<1).

Any ideas / suggestions / questions? Thanks in advance.


  Reply With Quote

Old   June 20, 2008, 23:02
Default Re: 1D3D GT coupling :intake manifold convergence
Posts: n/a
i have done much more calculation of 1D/3D couple on intakemanifold , rpm from 1000 to 6000, it works well.
  Reply With Quote


Thread Tools
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 On
Pingbacks are On
Refbacks are On

Similar Threads
Thread Thread Starter Forum Replies Last Post
Intake Manifold David Baker FLUENT 1 December 31, 2013 09:26
1D3D Coupling GT-Power/StarCD Hubert Janocha CD-adapco 16 August 15, 2010 08:03
Intake manifold analysis mehndan CD-adapco 3 August 22, 2008 04:24
1D3D GT coupling:how to read the cfd file Micky CD-adapco 1 June 20, 2008 22:56
1D3D-Coupling StarCD GT-Power Hubert Janocha CD-adapco 3 November 15, 2005 13:43

All times are GMT -4. The time now is 05:36.