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

node values vs. no node values in fluent

Register Blogs Community New Posts Updated Threads Search

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   August 26, 2011, 13:17
Default node values vs. no node values in fluent
  #1
New Member
 
Join Date: May 2011
Posts: 23
Rep Power: 14
user0314 is on a distinguished road
In fluent I am viewing filled velocity contours on my inlet.

When I check the box 'node values' and when I uncheck the box the results look dramatically different as shown in my two .png files attached.

If 'node value' means interpolation, how can it be that the two results have different orders of magnitude?

I have a 3D geometry spinning disk. The fluid is prescribed as a moving reference frame and the walls are prescribed at rotating at 0 rpm in the relative reference frame to the adjacent fluid. Does it have to do something with that?

Thanks.
Attached Images
File Type: jpg zvelocity_nodevalues.jpg (56.9 KB, 139 views)
File Type: jpg zvelocity_no_nodevalues.jpg (57.2 KB, 122 views)
user0314 is offline   Reply With Quote

Old   August 28, 2014, 05:48
Default
  #2
Member
 
Qureshi M Z I
Join Date: Sep 2013
Posts: 79
Rep Power: 12
m zahid is on a distinguished road
have you find the answer of this ? please share the answer

thanks
m zahid is offline   Reply With Quote

Old   February 6, 2015, 05:03
Default
  #3
New Member
 
sajad
Join Date: Aug 2010
Posts: 17
Rep Power: 15
sajad is on a distinguished road
Quote:
Originally Posted by m zahid View Post
have you find the answer of this ? please share the answer

thanks
Hi
I have sampe problem, any answwer for this?
thanks
sajad is offline   Reply With Quote

Old   February 6, 2015, 05:32
Default
  #4
Senior Member
 
Cees Haringa
Join Date: May 2013
Location: Delft
Posts: 607
Rep Power: 0
CeesH is on a distinguished road
Looking at the shown images, it looks like the left case is simply the velocity of the rotating frame plotted in the absolute frame, while the right case plots the z-velocity with respect to the reference frame. Because the actual velocities are an order of magnitude smaller than the frame velocity, the right one basically doesn't show anything. That's my idea on what we see here. Why we see it is a different question, and to that I have no answer currently.
CeesH is offline   Reply With Quote

Old   June 30, 2019, 04:14
Default
  #5
New Member
 
ALI
Join Date: Jul 2016
Posts: 14
Rep Power: 9
ars511 is on a distinguished road
If you are plotting contours to show the effect of a porous medium or fan, to depict a shock wave, or to show any other discontinuities or jumps in the plotted variable, you should use cell values; In other words for the fields with high gradiants the interpolation on the nods will result in false value.in such cases you have to choose either cell value or making mesh samaller. if you use node values in such cases, the discontinuity will be smeared by the node averaging for graphics and will not be shown clearly in the plot.
ars511 is offline   Reply With Quote

Reply


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
Fluent jobs through pbs ibnkureshi FLUENT 5 June 9, 2011 13:43
few quesions on ANSYS ICEMCFD and FLUENT Prakash.Paudel ANSYS 0 August 12, 2010 12:07
Fluent 2D Reference Values Adam FLUENT 1 January 16, 2009 02:58
Accessing node values using a UDF Nico FLUENT 2 December 20, 2007 02:50
shear rate values with fluent IƱigo Main CFD Forum 0 October 17, 2005 06:25


All times are GMT -4. The time now is 08:48.