# how to get the right y+ value.

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

 May 29, 2010, 02:07 how to get the right y+ value. #1 New Member   danardono Join Date: Apr 2009 Posts: 4 Rep Power: 10 Does anybody know how to get the right y+ value in Ansys CFX? As long as I know, there are 2 ways to get the result, but they give different values for the same CFD calculation results. #1. On "tools", the function calculator. Choose function: areave Location: "walls" variable: yplus (not solver yplus). This option will give a certain y+ value. #2. Under "outline" apply the following settings to default domain: -mode : variable -variable : Yplus This option will give a range of y+ on entire surface (walls) of the model. In my case, the y+ gotten from #1 is not in the range of y+ gotten from #2. Thanks a lot..

 May 29, 2010, 07:08 #2 Super Moderator   Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 14,190 Rep Power: 109 But you are comparing an area averaged y+ to a y+ range, so you are not comparing the same thing. Can you explain what you mean better?

 May 29, 2010, 09:08 #3 New Member   danardono Join Date: Apr 2009 Posts: 4 Rep Power: 10 Thanks a lot for responding. I know that I compare different things. But in my opinion (please tell me if I'm wrong), the y+ area averaged value should be in the y+ range value. In my case, for example the area averaged value is around 22, but the range is from 0 to 11. Actually what I need is to check the y+ value, in order to check the accuracy of the 3D problems. Would you please tell me which way is the best to check th y+? regards

 May 29, 2010, 17:59 #4 Super Moderator   Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 14,190 Rep Power: 109 Generally there are only a few surfaces where the y+ matters. So you look at those surfaces and do plots of y+ or max/min functions on the surfaces of interest to check they are OK. There is no point doing averages over the entire domain if it includes walls of no interest.

 May 30, 2010, 04:38 #5 New Member   danardono Join Date: Apr 2009 Posts: 4 Rep Power: 10 OK, I understand.. Thank you very much for your help.. best regards..

 Tags ansys cfx, y+ value

 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

All times are GMT -4. The time now is 04:45.