tilopa
Well-Known Member
This is an update of the closed wing design that addresses the difficulty of proper controls and vertical stability. First, to get the awkward part out of the way, I really wasn't going for the flying-penis design, this is just my lack of skill with sketchup to make a proper cockpit and fuselage. Imagine a sailplane cockpit with a fuse that starts above center (behind the pilots head). Also, the wingtips should be a smoother transition with a slight winglet. Main wheels will be about a foot in front of the duct at the bottom of the fuse. Specs: single place - composite length = 23ft wingspan = 27ft height = 8ft empty weight = 500 lbs Wing area = 80 ft2 Engine = Yamaha 1.0 liter 4-stroke 4 cyl - 150hp prop = fixed pitch 40" diameter Center of Gravity = red line in top and right views Center of Lift = Blue line in top and right views Assumptions: - One piece spar-less wing will reduce weight. - Design will reduce drag from less interference drag and less wingtip drag. - Rear forward swept wing will produce a higher lift-to-drag ratio. - Greater horizontal stability will be achieved from having a rear and front wing which will act to balance around CG This revision addressed: - vertical stability concerns by increasing the length and putting a vertical stabilizer and rudder at the end. And though a forward swept anhedral wing will have poor vertical stability I feel the front rear swept dihedral wing will offset that. - Lack of control surfaces, ailerons on the rear wing, rudder and elevator at the tail end. Concerns: - Ailerons position and surface area is enough. - Aileron control cable would have to be run through the front wing and around to the back. - Difficulty of analysis prior to building. 
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