Round tube versus airfoil shape. Around bar like in the horizontal and vertical stabilizer 9 times more drag than an airfoil shape. An old video but it get across the point.
https://youtu.be/ftq8jTQ8ANE
Moderator: scubarider2
av8rps wrote:I have my horizontal stabilizer struts on my Kitfox streamlined nicely... ...and have a really fast Model 4, even when on floats. So something is working.
av8rps wrote:Wow Paul! Awesome work with screen captures and formulas. I've learned even more from looking at them.
So in thinking about all this more, I do want to remind everyone here that the leading edge of the tail is not the equivalent of a round tube going through the air, as it's the back side of the round tube that is where most of the drag comes from. Having fabric covering on the back side of the round tube (as in tailfeathers) changes everything. It would be really interesting to see that same test comparing a non ribbed flying surface vs a streamlined flying surface. I would speculate the unribbed piece would be only 25 to 35% more drag, but that is purely my speculation / guesstimate.
The point of all that is that with 8 separate flying wires each essentially the same length as the leading edges of the tailfeathers, the wires represent more length, therefore more drag overall. Or at least the same drag as the rest of the tail. I have my horizontal stabilizer struts on my Kitfox streamlined nicely, and have the horiz stab and elevator ribbed, and have a really fast Model 4, even when on floats. So something is working.
Anyhow, just trying to stimulate minds of those contemplating modifications to their airplanes. Thanks again for all that research Paul.