Thanks to members of this forum, I have abandoned the Hershey bar and begun researching a tapered wing planform for my next project. As this will be a composite wing (with an as of yet undetermined laminar airfoil), I think I want a straight (180 degree), one piece spar from tip to tip. Also, the spar will be positioned in the thickest section of the airfoil. So my questions are these:
1. With these two variables "fixed" (straight spar, located at max depth), does that not drive me to a certain LE "sweep" based upon the airfoil(s) of choice? For example, if the spar is located at the thickest section (50% chord, for argument), and the root and tip have the same section (but the tip is 33% smaller ), I'm stuck with a planform that resembles a P-51/ or ME109 as a matter of geometric certainty, right?
2. Most modern aerobatic aircraft have a tapered wing, yet the LE is acute to the CL of the aircraft (no sweep). Are the spars also 180 degrees from tip to tip? If so, they must not be at the thickest part of the wing all the way to the tip. The main spar on my woodwing Mooney was 180 degrees, but it was located well forward at the root and ended up at nearly 80% chord at the tip due to the straight LE. Is this an acceptable trade (structure for aero)?
3. Finally, what is the "accepted" definition of a "swept wing" (or straight, for that matter)? All the text I have read indicates the degree of sweep is is defined by the 0%,25%, 37% or 100% chord line, depending upon the source. So for the purpose of subsonic behavior of a particular planform, when is a wing "swept"?
Thanks in advance
Mike
1. With these two variables "fixed" (straight spar, located at max depth), does that not drive me to a certain LE "sweep" based upon the airfoil(s) of choice? For example, if the spar is located at the thickest section (50% chord, for argument), and the root and tip have the same section (but the tip is 33% smaller ), I'm stuck with a planform that resembles a P-51/ or ME109 as a matter of geometric certainty, right?
2. Most modern aerobatic aircraft have a tapered wing, yet the LE is acute to the CL of the aircraft (no sweep). Are the spars also 180 degrees from tip to tip? If so, they must not be at the thickest part of the wing all the way to the tip. The main spar on my woodwing Mooney was 180 degrees, but it was located well forward at the root and ended up at nearly 80% chord at the tip due to the straight LE. Is this an acceptable trade (structure for aero)?
3. Finally, what is the "accepted" definition of a "swept wing" (or straight, for that matter)? All the text I have read indicates the degree of sweep is is defined by the 0%,25%, 37% or 100% chord line, depending upon the source. So for the purpose of subsonic behavior of a particular planform, when is a wing "swept"?
Thanks in advance
Mike
