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

pathline difference in fan for 1 order and 2 order scheme

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

Reply
 
LinkBack Thread Tools Display Modes
Old   August 25, 2013, 11:07
Default pathline difference in fan for 1 order and 2 order scheme
  #1
New Member
 
thomasesel
Join Date: Jul 2009
Posts: 13
Rep Power: 8
tongnan is on a distinguished road
Hi, I am trying to simulate a fan. In my case, the full 3D fan is modeled with the casing together.

The upstream of the fan is an air chamber and set as pressure inlet 0 Pa. the downstream is set as pressure outlet 0 Pa. The rotating fan is set as MRF. SST model is used.

At first, the rotating speed is increased step by step, the first order upwind for k, omega and momentan equations and 10 times smaller under relaxation factor are used. The pathlines are reasonable, figure 1. Then, the calculation runs under 2 order upwind, but the pathlines are greatly differnce from the figure 1, s. figure 2. It seems the blowing of the fan does not continue.

Can anyone tell me the possible reasons for the simulations?

Thank you in advance!
Attached Images
File Type: png fig1.png (60.8 KB, 8 views)
File Type: png fig2.png (39.8 KB, 9 views)
tongnan is offline   Reply With Quote

Old   August 27, 2013, 15:31
Default
  #2
New Member
 
thomasesel
Join Date: Jul 2009
Posts: 13
Rep Power: 8
tongnan is on a distinguished road
does anyone have an idea?
thank you!
tongnan is offline   Reply With Quote

Reply

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
Difference between first order and second order msatrustegui FLUENT 2 December 5, 2012 06:54
2nd order boundary conditions for 2nd order discretization? quarkz Main CFD Forum 30 December 26, 2011 08:12
2nd order upwind scheme (Fluent and CFX) Far FLUENT 0 May 22, 2011 01:50
how to understand high resolution scheme and high order scheme iilw1314 Main CFD Forum 3 September 30, 2010 10:43
High order difference scheme for KIVA3v2??? LiQiang Main CFD Forum 1 May 9, 2005 13:50


All times are GMT -4. The time now is 01:58.