# Wall functions - iterative approach

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

 May 2, 2005, 17:29 Wall functions - iterative approach #1 agg Guest   Posts: n/a Hello, I am using LES for my flow. I am not resolving near wall structures and hence trying to use the wall function approach, i.e. using u/ut = 1/0.41 * ln(y*ut/nu) + 5.2 Here, u and y are the streamwise velocity and distance of the grid point nearest to the wall. nu is the kinematic viscosity. In the above equation the only unknown is friction velocity ut: ut = sqrt(tau_w/rho) where tau_w is the wall shear stress and rho is density Does anyone have any experience with the methods (iterative) used to obtain ut? Thanks -agg

 May 13, 2005, 12:25 Re: Wall functions - iterative approach #2 etyo Guest   Posts: n/a I have faced the same problem before but I was dealing with RSM and not LES, the procedure is straight forward. Guess one value of Ut (on the right hand side) and iterate till you get the same value on the left hand side. You might need to use the length scale from the mixing length theory as the minimum allowable length (by using the MIN function). If you still facing problems I suggest you to consult Prof. Lars Davidson (lada@tfd.chalmers.se).

 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 Attesz CFX 7 January 5, 2013 04:32 simvun OpenFOAM Other Meshers: ICEM, Star, Ansys, Pointwise, GridPro, Ansa, ... 48 May 14, 2012 05:20 cristobal OpenFOAM 2 May 6, 2011 04:10 tutlhino OpenFOAM Pre-Processing 0 July 2, 2007 05:04 Andrea CFX 2 October 11, 2004 05:12

All times are GMT -4. The time now is 03:28.