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

External Aerodynamic Simulation+negative densities

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

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   February 18, 2008, 04:51
Default External Aerodynamic Simulation+negative densities
  #1
Ramkumar
Guest
 
Posts: n/a
Hi all, I would like to know the following queries on STAR-CD:-

1) What boundary conditions on each face of the bounding box need to be given for simulating the aircraft encountering a large side-slip angle simultaneously with angle of attack.

2) When polyhedral cells are created and inviscid option is selected for solving, the solution diverged and the solver reported that the model got negative densities. I didn't understand what is meant by negative densities and why it is reporting like that.

I will be pleased if somebody answers the above questions as soon as possible.

thanks and regards, rvramkumar.
  Reply With Quote

Old   February 18, 2008, 16:27
Default Re: External Aerodynamic Simulation+negative densi
  #2
ula
Guest
 
Posts: n/a
it means you have bad polyhedral cells in your geometry. Try the same case but with the trimmer model.
  Reply With Quote

Old   February 19, 2008, 05:18
Default Re: External Aerodynamic Simulation+negative densi
  #3
Ramkumar
Guest
 
Posts: n/a
Thanks. I'll try with trimmer model. Nevertheless, When the mesh is checked, it was not giving any errors. Why this ambiguity?
  Reply With Quote

Reply

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
negative densities john Siemens 0 March 19, 2008 07:32
negative densities Riyaz Ahamed Siemens 2 August 14, 2007 02:47
Negative densities!!! Nalleli Siemens 5 August 31, 2005 07:38
negative densities. Mihir Siemens 4 December 9, 2002 22:04
negative densities Fabrizio Grieco Siemens 4 October 30, 2000 02:47


All times are GMT -4. The time now is 20:18.