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Cecco May 16, 2012 03:28

Thickness boundary layer
 
Dear all,
how can I calculate the thickness of the boundary layer along a blade of an axial fan?

Thanks guys

Far May 17, 2012 03:09

You should run your ur calculation and then measure the thickness of boundary layer. However, for the purpose of fine tuning mesh parameters, use the flat plate boundary layer formulae

http://en.wikipedia.org/wiki/Boundary-layer_thickness

http://www.ae.metu.edu.tr/~ae244/doc...07/node12.html

Cecco May 17, 2012 11:29

Thank you man! Think I'm gonna do this:
1. I use the Blasius formula for flat plane in order to get an idea of the thickness
2. I run a first simulation containing something like 5 elements along this thickness
3. After that I could have the real measurement of the thinkness, so that I could run one more simulation more refined.

Far May 17, 2012 11:32

At least 10-15 nodes in boundary layer thickness. Also take care of first node position according to yplus requirement. Do not exceed the 1.2 ratio in BL


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