|February 24, 2012, 15:45||
Join Date: Feb 2012
Posts: 6Rep Power: 5
I am trying to get a better understanding of what the "Wall Roughness" box is (in the wall boundary layer box) referring to.
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.
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?
|February 24, 2012, 15:57||
Join Date: Oct 2010
Posts: 949Rep Power: 15
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.
Last edited by ghost82; February 25, 2012 at 03:44.
|Thread||Thread Starter||Forum||Replies||Last Post|
|Natural convection in a closed domain STILL NEEDING help!||Yr0gErG||FLUENT||3||June 12, 2013 02:12|
|Laminar flow and wall roughness||junbbung||FLUENT||1||December 2, 2012 06:57|
|Roughness Height of a wall||Vijay||FLUENT||0||December 17, 2009 16:13|
|Errors running allwmake in OpenFOAM141dev with WM_COMPILE_OPTION%3ddebug||unoder||OpenFOAM Installation||11||January 30, 2008 21:30|
|Wall Roughness Error||Ken||FLUENT||1||April 23, 2007 12:59|