Load Distribution on a Tapered Wing
Load Distribution on a Tapered Wing
(OP)
I cannot find a formula for calculating load distribution on a tapered wing. I am calculating deflection of a spar and the formula I'm using (D = WL^4/8EI where D is deflection) assumes that w is a uniform load along the span. I'm not sure if that assumption is correct for the wing design (I do not think it is as the wing has a taper ratio of .48) or if the assumption makes the results pessimistic (actual deflection will be less than calculated) or optimistic (deflection greater than predicted). Obviously, I'd prefer the former or, better still, something resembling reality.
Rich
Rich
RE: Load Distribution on a Tapered Wing
Anyway, pay no attention to the engineer who thinks he's funny.
So, go to John Anderson's book Fundamentals of Aerodynamics and I believe it is chapter 5 that has a decent numerical procedure for calculating the spanwise lift distribution of a wing.
That is all,
Tony
RE: Load Distribution on a Tapered Wing
Rich
RE: Load Distribution on a Tapered Wing
RE: Load Distribution on a Tapered Wing
RE: Load Distribution on a Tapered Wing
I think my planform comes close to the "ideal" elliptical lift distribution - if I get the washout correct.
I did a quick & dirty calculation using the so-called Schrenk method cited in Alex Strojnik's "Laminar Aircraft Design." When I plot the local Cl I get a hump in the distribution about 2/3 out on the semispan. Since I plan to use a slotted single-element flap, and haven't accounted for that in the calculation, my biggest fear is a nasty tip stall. Guess that's what I get for using a tapered planform.
Thanks again for the suggestions.
rich
RE: Load Distribution on a Tapered Wing
RE: Load Distribution on a Tapered Wing
Your lift distribution will completely change if you have a partial span flap installed. I expect you would find that the tip of the wing has a lower Cl with the flaps out. Tip stall becomes less of a problem if this is the case.
STF
RE: Load Distribution on a Tapered Wing
You can remove the hump in the spanwise loading by using washout - twist the wing so that the incidence of the airfoils decreases from root to tip.
RE: Load Distribution on a Tapered Wing