# Wall Roughness

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

 February 24, 2012, 15:45 Wall Roughness #1 New Member   Paul Join Date: Feb 2012 Location: CT Posts: 6 Rep Power: 7 I am trying to get a better understanding of what the "Wall Roughness" box is (in the wall boundary layer box) referring to. Roughness Height: Is this the height found on standard charts? (see http://www.engineeringtoolbox.com/su...cts-d_209.html). i.e. If I was to use Stainless Steel than the Roughness Height would be k=5E-5ft. Roughness Constant: Is the roughness constant the number calculated (relative roughness). i.e. Using the hydraulic diameter (d=23.5in), and k. Equation is r=k/d == having a value of 26E-6. Can someone please help? Thank you! Paul prasa likes this.

 February 24, 2012, 15:57 #2 Senior Member     Daniele Join Date: Oct 2010 Location: Italy Posts: 998 Rep Power: 18 Hi, You are right for the roughness height, but roughness constant isn't relative roughness: fluent uses this parameter to specify uniformity of roughness: since there is no indication on how to calculate it, you have to try and see if your simulation results approximate your experimental results; roughness constant=0,5 indicates a uniformal roughness; use values between 0,5 and 1 to specify non uniformal roughness. Daniele dynamic, prasa and Abhishek Chaudhary like this. Last edited by ghost82; February 25, 2012 at 03:44.

 February 24, 2012, 16:54 #3 New Member   Paul Join Date: Feb 2012 Location: CT Posts: 6 Rep Power: 7 Thank you Daniele, I appreciate your very quick responds.

 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 Yr0gErG FLUENT 3 June 12, 2013 02:12 junbbung FLUENT 1 December 2, 2012 06:57 Vijay FLUENT 0 December 17, 2009 16:13 unoder OpenFOAM Installation 11 January 30, 2008 21:30 Ken FLUENT 1 April 23, 2007 12:59

All times are GMT -4. The time now is 00:30.