Aerowerx
Well-Known Member
I have been working in XFLR5 on a tailless aircraft model.
Tandem seating or single seat is pretty straightforward, but I would prefer side-by-side seating.
This is turning out to be quite difficult. I have defined three load cases: minimum (150 lb pilot), mid (200 pound pilot---don't ask where I got that number
), and maximum (200 pound each pilot and passenger). Even small changes in weight has a huge effect on the pitching moment, requiring lots of trim to zero out the pitch. Depending on how I set it up, the minimum load sometimes doesn't work at all---it goes nose-up and into the stall so the analysis gives up..
I would very much like to avoid any possible extreme tail-heavy/nose-up situation.
One solution is to design it just for me, assuming I don't go on a diet. If designed for "cheeseburger and donuts" pilots to fly with no trim, then with any passenger it would be nose-heavy requiring some up-trim on the elevator. This would certainly be safer, but then skinny pilots couldn't fly it. If designed for skinny pilots, then "healthy male" pilots with passenger would require excessive nose-up trim. Or design for something between mid and maximum, like maybe 300 pound pilot+passenger, which would require nose-down trim when flying alone and nose-up with a large passenger.
Any suggestions? Like using a different wing sweep? Or compromise and stick with the tandem seating?
How do they get away with side-by-side seating on the Horten PUL-10 and Mitchell T-10? Are there any other tailless side-by-sides out there, and how do they do it?
Tandem seating or single seat is pretty straightforward, but I would prefer side-by-side seating.
This is turning out to be quite difficult. I have defined three load cases: minimum (150 lb pilot), mid (200 pound pilot---don't ask where I got that number
), and maximum (200 pound each pilot and passenger). Even small changes in weight has a huge effect on the pitching moment, requiring lots of trim to zero out the pitch. Depending on how I set it up, the minimum load sometimes doesn't work at all---it goes nose-up and into the stall so the analysis gives up..I would very much like to avoid any possible extreme tail-heavy/nose-up situation.
One solution is to design it just for me, assuming I don't go on a diet. If designed for "cheeseburger and donuts" pilots to fly with no trim, then with any passenger it would be nose-heavy requiring some up-trim on the elevator. This would certainly be safer, but then skinny pilots couldn't fly it. If designed for skinny pilots, then "healthy male" pilots with passenger would require excessive nose-up trim. Or design for something between mid and maximum, like maybe 300 pound pilot+passenger, which would require nose-down trim when flying alone and nose-up with a large passenger.
Any suggestions? Like using a different wing sweep? Or compromise and stick with the tandem seating?
How do they get away with side-by-side seating on the Horten PUL-10 and Mitchell T-10? Are there any other tailless side-by-sides out there, and how do they do it?
