wingspan33 wrote:One of my ideas for future HG design is to have flexible vertical posts at each batten station. A cord would connect at the mid point of each post. The lower surface battens would also be flexible in the area of the high camber point (of the upper batten).
So you want to connect the top battens with the bottom battens and shorten their distance on demand. (Does this correctly represent your idea?)
Pulling symmetrically on the cord would create a better slow speed profile to the airfoil.
Slow speed airfoils are those with high lift coefficient. The lift coefficient is is about proportional to camber.
To increase camber, both sides of the airfoil should increase their bend. This will only happen if both ends of the battens cannot move relative to their cousin. Else, a pull on the chord might flatten the airfoil rather than make it more cambered.
I don't see much of a negative associated with this idea (except a tiny weight penalty).
The pulling force has to be countered by the air frame. Making a good hang glider sail involves balancing dynamic forces and leading edge bend. Depending on the relative magnitude, the pull on the chord may add to the bend. I am not sure whether the effect would be desirable or not.
---<)kaimartin(>---