# Is Y plus =3 ok for standard wall function???

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

 May 6, 2005, 15:26 Is Y plus =3 ok for standard wall function??? #1 Thomas Guest   Posts: n/a Sponsored Links Hello fluent users is y+=3 ok for the standard wall function approach? In the users guide they say the y+ value should be at about 30. Or can i also use the enhanced wall treatment when the y+ is also at about 3 to 4? thanks for your help thomas

 May 7, 2005, 00:08 Re: Is Y plus =3 ok for standard wall function??? #2 pUl| Guest   Posts: n/a Manual wise NO. However, I would love if someone could clearly (and i mean CLEARLY) explain the difference in results (if any) if y+ = 30 is not adhered to, when using Std. Wall functions.

 May 9, 2005, 14:11 Re: Is Y plus =3 ok for standard wall function??? #3 kamesh Guest   Posts: n/a hi guys The value of Y plus depends on the type of turbulence model.for example K-epsilon (infact every) Turbulence model without wall treatment assumes full turbulence in domain of integration.If the value of y+ is greater than 30 i.e some where in the middle(i mean not near wall region), the results of turbulence model is fairly good with experimental values. So if we dont take wall treatment into consideration one should take y+ more than 30 to get reasonably good results...... kamesh

 May 10, 2005, 15:13 Re: Is Y plus =3 ok for standard wall function??? #4 Riaan Guest   Posts: n/a Well, in my cases, I have y+=1 even when using wall functions. The model I am using is the Realizable K-eps with Non-equilibrium wall functions. For the SA model, y+ = 1 and y+>30 give similar results and compare well with experimental data (at least for delta wings at alpha <10deg)

 May 12, 2005, 13:08 Re: Is Y plus =3 ok for standard wall function??? #5 kamesh Guest   Posts: n/a hi if u use standatd wall functions ther will be no much pblm if u have less y+ value.U should be careful about wall your results when you are not using wall functions.

 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 ivanyao OpenFOAM Running, Solving & CFD 1 October 12, 2012 09:31 AlmostSurelyRob OpenFOAM 3 June 24, 2011 13:06 johnblund OpenFOAM 0 March 10, 2011 09:50 yka8150 Main CFD Forum 0 September 21, 2009 23:08 Rasmus Gjesing (Gjesing) OpenFOAM Native Meshers: blockMesh 10 April 2, 2007 14:00