# y+ in fluent

 User Name Remember Me Password
 Register Blogs Members List Search Today's Posts Mark Forums Read

 March 26, 2012, 17:20 y+ in fluent #1 Senior Member   MAZI Join Date: Oct 2009 Posts: 100 Rep Power: 9 Sponsored Links 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?

 March 26, 2012, 18:11 #2 Super Moderator   Sijal Join Date: Mar 2009 Location: Islamabad Posts: 4,331 Blog Entries: 6 Rep Power: 45 At least 11.06 and 30 for better performance of wall function.

 March 26, 2012, 18:56 #3 Senior Member     Alex Pasic Join Date: Aug 2011 Location: Croatia Posts: 192 Rep Power: 8 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.

 March 26, 2012, 18:58 #4 Senior Member   MAZI Join Date: Oct 2009 Posts: 100 Rep Power: 9 I DONT need the contour of y+. i need value of y+ in the first gird near the wall.

 March 26, 2012, 19:00 #5 Senior Member     Alex Pasic Join Date: Aug 2011 Location: Croatia Posts: 192 Rep Power: 8 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.

 March 26, 2012, 19:03 #6 Senior Member   MAZI Join Date: Oct 2009 Posts: 100 Rep Power: 9 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.

 March 26, 2012, 19:12 #7 Senior Member     Alex Pasic Join Date: Aug 2011 Location: Croatia Posts: 192 Rep Power: 8 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..

 Thread Tools Display Modes Linear Mode

 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 OffTrackbacks are On Pingbacks are On Refbacks are On Forum Rules

 Similar Threads Thread Thread Starter Forum Replies Last Post knight Fluent UDF and Scheme Programming 12 March 5, 2016 02:26 Volker Pawlik FLUENT 7 May 22, 2014 22:30 Steven Fluent UDF and Scheme Programming 4 September 20, 2013 16:30 renyun0511 OpenFOAM Running, Solving & CFD 8 July 6, 2010 06:24 Lourival FLUENT 3 January 16, 2008 17:48