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-   -   Lift distribution (http://www.cfd-online.com/Forums/star-ccm/81332-lift-distribution.html)

PB4 October 24, 2010 04:26

Lift distribution
 
Hi there,

I am fairly new to CFD so please be nice :)
I am looking to plot lift distribution over my wing, to help me predict initial spanwise stall point so I can adjust wing parameters (mainly twist and tip airfoil characteristics, the rest is fixed), the reason I want to use CFD as opposed to other well documented methods is that my wing is quite "dirty", I have 3 engine nacelles on the leading edge and a retractable float which fits under the wing at about 60% span though not flush with the surface, all that I'm sure will affect the results.
my questions are :
- How do I plot lift distribution along span ? I've played around with overall wing lift coef and section pressure coefs but would like to see some kind of spanwise lift curve, local Cl etc
- What would typically be mesh requirements for "good enough" spanwise lift distribution results ? I'm not looking into accurate drag or even lift values, just the distribution of it.

thanks all for your help !

Larsen October 28, 2010 06:59

Split the surface up in a upper and lower wing. Make an X-Y plot and plot Span - Pressure. Later you should export the file and do a regression analysis in your preffered data manager (Igor or etc..).

There is no good answer to what is fine enough mesh, but you should check that the Wall y+ values are within the correct value for the turbulence modle you are using. An general answer is that the more complex geometry requires finer mesh.


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