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Franny March 27, 2007 10:00

Boundary layer thickness
 
Hi all,could anyone suggest the way to calculate boundary layer thickness?I need to plot th e velocity profile and see where its value is equals to 99 of the freestream value.I think i need to plot it along the polyline.What do you think?

Regards.

Franny

Adam March 29, 2007 07:08

Re: Boundary layer thickness
 
Unfortunatly, you have to do it the hard way!

1) Create a line perpendicular to the surface at the point of interest, making sure that the line is longer than the boundary layer thickness.

2) Export the velocity profile of that line.

3) Find 0.99xUfreetsream to aqcuire the boundary layer thickness.

4) You can use Matlab etc (trapeziodal function) to calculate disp, mom thickness and hence shape factor from the velocity profile.

I don't think you can do it in CFX itself, so you have to do it the long way.

Hope this helps

Adam

Omer March 30, 2007 18:28

Re: Boundary layer thickness
 
I was just wondering why you would need the boundary layer thickness. Is it because you need to have a resolved boundary layer for your model? If so , plotting Y+ contour would be a good idea.


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