CFD Online Logo CFD Online URL
Home > Forums > General Forums > Main CFD Forum

atmospheric roughness height

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

LinkBack Thread Tools Search this Thread Display Modes
Old   December 27, 2002, 16:32
Default atmospheric roughness height
Posts: n/a

I work with atmospheric boundary layer.

wind profile of inlet boundary layer is : u=u_tau/kappa*ln(z/z_0) where roughness height z_0=0.07 meter (flat plane)

Turbulence intensity profile : I_t=1/ln(z/z_0)

I use a law of wall : u_plus=1/kappa*ln(z+/z+_0)

In StarCD Methodology page 6-6, i found that y_p (height of the center of cell) should be 4 times larger than the roughness height.

My questions :

1. I'm looking for publications on roughness height and CFD (witch grid can i take), could you help me?

2. Witch y+ range can i give?

3. Is this modelisation good?

4. Witch lenght scale can i take (i just know that L_30m=100m)?

PS : I try a "power law" for the wind profil and i obtain bad results because i use low wind and power low is for strong wind

  Reply With Quote


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

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 Off
Trackbacks are Off
Pingbacks are On
Refbacks are On

Similar Threads
Thread Thread Starter Forum Replies Last Post
Setting of Roughness Constant and Height Sing FLUENT 7 June 23, 2021 14:26
UDF: for the setting of roughness height maximus FLUENT 1 September 10, 2014 16:20
how to choose the roughness height icestar FLUENT 10 August 31, 2012 09:00
Trouble with Roughness Height Dragin STAR-CCM+ 1 June 17, 2009 16:32
atmospheric roughness height Alain BASTIDE Siemens 5 December 30, 2002 05:26

All times are GMT -4. The time now is 07:47.