Influence of wind gradient on lifting line

[nico]

Hi,


I am wondering about the influence of wind gradient on lifting line results.
In the paper by tspeer http://www.tspeer.com/Planforms/Planar.htm
the author says "lifting line analysis performed in a nonuniform flow, such as a wind gradient, can be transformed into an equivalent problem in a uniform flow".
Here is what i understand; the lift (bound vortices) will be angled forward (or backward) by the wind gradient. And the effect of the gradient on the trailing vortices is not taken into account (since small). Am i right?

Thanks

[tspeer]

There was an article by Peter Lissaman in one of the AIAA Ancient Interface Symposia in which is looked at this issue. I have the paper, but unfortunately I didn't copy the down the year! Mid to late '70's probably. You may be able to get it from a university engineering library - I found it at Stanford.

You can get a reasonable approximation by changing the chord to represent the loss in dynamic pressure and the incidence to represent shear in the apparent wind direction.