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

Formula for velocity in buffer layer of turbulent boundary layer

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

LinkBack Thread Tools Display Modes
Old   February 3, 2012, 12:57
Default Formula for velocity in buffer layer of turbulent boundary layer
New Member
Nikolay Vinnichenko
Join Date: Nov 2010
Posts: 14
Rep Power: 7
nickvinn is on a distinguished road
I was calculating turbulent viscosity according to Baldwin-Lomax model for the fixed velocity field of flat plate turbulent boundary layer and had problems with too low viscosity in the outer layer of the model. Now I realize that the velocity profile by Reihardt u^+=ln(1+\kappa y^+)/\kappa+7.8*(1-exp(-y^+/11)-y^+*exp(-y^+/3)/11), which I was using, yields bad F-function with peak located too close to the wall. I changed for piecewise u^+=piecewise(y^+<5, y^+, y^+<30, 5*ln(y^+)-3.05, ln(y^+)/\kappa+5.5). It yields F-function with correct global maximum. However, du^+/dy^+ is discontinuous, so another local maximum exists closer to the wall. I'm afraid that for some values of parameters I can take it for the right one. Is there any analytical expression for velocity profile with correct description of buffer layer (5<y^+<30) and continuous derivative?
nickvinn is offline   Reply With Quote


Thread Tools
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 On
Pingbacks are On
Refbacks are On

Similar Threads
Thread Thread Starter Forum Replies Last Post
Water subcooled boiling Attesz CFX 7 January 5, 2013 04:32
[GAMBIT] 3D boundary layer and meshing problem in GAMBIT 2.4.6 prashanthreddyh ANSYS Meshing & Geometry 1 December 20, 2011 01:35
Turbulent boundary layer resolution deji OpenFOAM 2 June 15, 2011 13:57
Turbulent Boundary Layer Reference Erika Johnson FLUENT 2 January 27, 2006 10:10
Boundary Layer Meshing of a nosecone Chris FLUENT 1 March 15, 2005 13:42

All times are GMT -4. The time now is 14:20.