CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > General Forums > Main CFD Forum

very basic question regarding fluid mechanics

Register Blogs Community New Posts Updated Threads Search

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   February 13, 2003, 06:51
Default very basic question regarding fluid mechanics
  #1
praveen
Guest
 
Posts: n/a
Hi guys,

How can I find friction velocity if I know the bulk velocity. fluid is water. i am using a square duct configaration. i know only the bulk Reynolds number and fluid properties.

please help me.

praveen
  Reply With Quote

Old   February 13, 2003, 11:15
Default Re: very basic question regarding fluid mechanics
  #2
Holidays
Guest
 
Posts: n/a
I seem to remember something of the form of Cmu^0.25 * sqrt (k) exists at a wall...
  Reply With Quote

Old   February 13, 2003, 11:26
Default Re: very basic question regarding fluid mechanics
  #3
Praveen
Guest
 
Posts: n/a
friction velocity = sqrt( shear stress on wall/density )

You need to know the shear stress on the wall to calculate friction velocity.
  Reply With Quote

Old   February 13, 2003, 11:53
Default Re: very basic question regarding fluid mechanics
  #4
ken
Guest
 
Posts: n/a
Is this a homework problem? Check out "A First Course in Turbulence" (Tennekes & Lumley) Chapter 5.2
  Reply With Quote

Old   February 14, 2003, 04:19
Default Re: very basic question regarding fluid mechanics
  #5
Holidays
Guest
 
Posts: n/a
Praveen,

Thank you, but I believe I knew that. However the formula I gave you is used in CFD at the walls I believe. You could check T&L as Ken adviced.
  Reply With Quote

Reply


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
[GAMBIT] Basic Question - Mesh Quality SheffieldStudent ANSYS Meshing & Geometry 8 December 15, 2010 18:24
basic question about the pressure AirS OpenFOAM Post-Processing 5 July 29, 2010 13:07
basic question for pressure BC vivien OpenFOAM 0 November 23, 2009 06:01
Power law fluid question Wesley OpenFOAM Running, Solving & CFD 0 April 3, 2009 17:21
A question about Fluid Mechanics and FLUENT cc FLUENT 5 January 24, 2006 12:07


All times are GMT -4. The time now is 01:15.