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

y+ in fluent

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

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   March 26, 2012, 18:20
Default y+ in fluent
  #1
Senior Member
 
MAZI
Join Date: Oct 2009
Posts: 103
Rep Power: 16
mazdak is on a distinguished road
i simulated turbulent flow in a pipe. how can i calculate y+ in the first grid near the pipe wall via fluent?
to make sure that my results are correct, the mentioned y+ should be over 30? or over 11?
mazdak is offline   Reply With Quote

Old   March 26, 2012, 19:11
Default
  #2
Far
Super Moderator
 
Sijal
Join Date: Mar 2009
Location: Islamabad
Posts: 4,553
Blog Entries: 6
Rep Power: 54
Far has a spectacular aura aboutFar has a spectacular aura about
Send a message via Skype™ to Far
At least 11.06 and 30 for better performance of wall function.
Far is offline   Reply With Quote

Old   March 26, 2012, 19:56
Default
  #3
Senior Member
 
scipy's Avatar
 
Alex Pasic
Join Date: Aug 2011
Location: Croatia
Posts: 199
Rep Power: 15
scipy is on a distinguished road
Send a message via Skype™ to scipy
Graphics and animations -> Contours -> pick Turbulence then in the drop down menu below pick Wall Yplus. Ticked "Filled" in the upper left corner and select your pipe wall in the list of surfaces, then display.. You can adjust your scales by unticking Auto range and putting in a manual minimum and maximum.
scipy is offline   Reply With Quote

Old   March 26, 2012, 19:58
Default
  #4
Senior Member
 
MAZI
Join Date: Oct 2009
Posts: 103
Rep Power: 16
mazdak is on a distinguished road
I DONT need the contour of y+. i need value of y+ in the first gird near the wall.
mazdak is offline   Reply With Quote

Old   March 26, 2012, 20:00
Default
  #5
Senior Member
 
scipy's Avatar
 
Alex Pasic
Join Date: Aug 2011
Location: Croatia
Posts: 199
Rep Power: 15
scipy is on a distinguished road
Send a message via Skype™ to scipy
That is what the contour is going to be showing.. You can right click anywhere on the wall and it will read out the y+ value in the textual interface part of Fluent.
scipy is offline   Reply With Quote

Old   March 26, 2012, 20:03
Default
  #6
Senior Member
 
MAZI
Join Date: Oct 2009
Posts: 103
Rep Power: 16
mazdak is on a distinguished road
if i need the y+ on nodes what should i do? cause if i right click on the geometry
in fact i am picking up a random point.
mazdak is offline   Reply With Quote

Old   March 26, 2012, 20:12
Default
  #7
Senior Member
 
scipy's Avatar
 
Alex Pasic
Join Date: Aug 2011
Location: Croatia
Posts: 199
Rep Power: 15
scipy is on a distinguished road
Send a message via Skype™ to scipy
OK, so if I'm understanding correctly you want a list of y+ values at a certain cross section of the pipe for example..

Plots -> XY Plot -> Set up -> Y Axis again Turbulence, beneath that Yplus, leave X Axis as Direction vector. Then beneath the list of surfaces click New surface -> Iso-surface -> on the right pick your pipe wall -> on the left pick under "Surface of constant" pick Mesh -> then (this part I'm going to guess as I can't see your geometry) you'd pick either X, Y or Z coordinate in the drop down menu beneath the upper Mesh choice. Basically, let's say your pipe centerline is the Z axis.. you would choose Z-Coordinate and then if the pipe goes from (0 0 0) to (0 0 10) meaning it's 10 meters long, you would enter anything between 0 and 10 in the Iso-Values field and that would be the cross section position where it's gonna display the y+ plot. So for example you'd put 5 in the Iso-Values and click Create.

Then you're back at the plot window and now you select the newly created surface named "z-coordinate-bla", in the upper left Node values is probably ticked, if not - tick it. Then you'd put 1 in the X or Y field (test for urself) under plot direction and click Plot.. there goes your plot of y+ values over a pipe cross section. If you tick Write to file in the upper left corner Plot button will change to a Write button and you can write the values over node positions in the .txt file.

/edit .. Correction, 1 doesn't go in the Z field since that's the cross section position..
scipy is offline   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
Stopping a Fluent batch job AND saving the data! Possible? Volker Pawlik FLUENT 13 December 28, 2020 05:16
A Problem of Fluent Interpreted UDF: parse error knight Fluent UDF and Scheme Programming 25 August 16, 2018 11:26
Two questions on Fluent UDF Steven Fluent UDF and Scheme Programming 7 March 23, 2018 04:22
Compared MRFSimpleFoam and Fluent in a centrifugal pump! renyun0511 OpenFOAM Running, Solving & CFD 8 July 6, 2010 07:24
Problems in lauching FLUENT Lourival FLUENT 3 January 16, 2008 17:48


All times are GMT -4. The time now is 23:37.