# Boundary Layer thickness

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

 March 4, 2010, 09:10 Boundary Layer thickness #1 New Member   Join Date: Dec 2009 Posts: 25 Rep Power: 9 Hi, I have a CFD model and i am trying to improve the density of the mesh inside the BL via additional prism layers. One thing i want to know is how thick (aproximately) the BL is so i can calculate how many layers i need. Does anyone know a way of estimating the thickness of the BL? Cheers

 March 4, 2010, 10:31 #2 Member   private Join Date: Mar 2009 Posts: 74 Rep Power: 10 Most introductory heat transfer texts have chapters on how boundary layer models are developed starting with the Navier-Stokes equations. These eventually lead to algebraic expressions for b. l. thickness as a function of Reynolds Number or other appropriate dimensionless groupings of fluid properties, physical dimensions, and driving functions. On my shelf of (antique) heat transfer texts are Schlichting (Boundary Layer Theory) and Chapman, (Heat Transfer). Others will be able to point to modern (and thus easier to find) texts. Good luck!

 March 5, 2010, 07:48 BL Thickness #3 New Member   Join Date: Mar 2009 Posts: 9 Rep Power: 10 Hi, If you're using commercial software try the user manual - CFX's details calculations for Y+ and B.L. thickness under "turbulence and near wall modelling". Good luck. Ianto

 April 29, 2010, 00:06 #4 New Member   E Busquets Join Date: Apr 2010 Posts: 2 Rep Power: 0 Hi, The way on which I usually calculate the boundary layer is: δ=5.2x/√Re Last edited by Enrique Busquets; May 3, 2010 at 01:35.

 April 30, 2010, 10:10 3 dimensional wing with winglet design Using Catia #5 New Member   turwidi buwang Join Date: Apr 2010 Posts: 1 Rep Power: 0 hello, I am in problem in Design wing with winglet using catia. I have design 3 dimensional wing with taper, sweep ang twist. But i cant design winglet on the tip. I will analize the design with Fluent. Anyone could help me....

 August 21, 2011, 06:28 empirical formula for B.L. thickness? #6 New Member   Join Date: Jan 2011 Posts: 6 Rep Power: 8 Hi all, I'd like to know boundary layer thickness around an airfoil (for ex. NACA 0012), I can use http://www.mh-aerotools.de/airfoils/javafoil.htm but the only result it can display are: v/V: normalized surface velocity d1: displacement thickness d2: momentum loss thickness d3: energy loss thickness Cfl: ocal friction coefficient H12: shape factor d1/d2 H32: shape factor d3/d2 flow state: laminar, turbulent, separated y1: the first cell height required for y+=1 (multiplied by 100 resp. in %) value useful for grid generation how can I calculate Boundary Layer thickness from any of these quantities? or is there a semi-empirical formula to calculate it for an airfoil like the one posted above? δ=5.2x/√Re

 August 23, 2011, 15:27 #7 New Member   Join Date: Jan 2011 Posts: 6 Rep Power: 8 up; maybe I should have opened another topic

 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 Lee,jangho FLUENT 5 January 5, 2017 11:03 ghazanfarzahedi Main CFD Forum 2 July 28, 2009 23:43 nat FLUENT 0 April 9, 2009 06:04 Neelima FLUENT 1 March 29, 2006 18:04 cfd-freak Main CFD Forum 3 March 27, 2003 13:18

All times are GMT -4. The time now is 06:21.