True, but as Eugene pointed out, the designer's tractor setup had issues with it as well. Bad design. And there are other pushers out there where this doesn't seem to be a problem.Well, with a rear prop it's going to ruin the flow anyways before the elevator. Some buffeting will always be expected.
Titan Tornado and Kolb MKiii are two for starters.A high wing has less wing/fuselage intersection separation issues than a low wing. The prop generally evacuates the area when under power.
The problem I see here is a lack of any engine cowl and the disturbed upper wing surface which is a bad place. Almost worse than a dive brake. I don't know of any aircraft that fly uncowled, above 80 mph.
Right. Looks like some Tornados are cowled, some not. This one says cruise at 75kts. http://lightsportaircraftpilot.com/titan_tornado_experimental_aircraft/pictures.htmlTitan Tornado and Kolb MKiii are two for starters.
That is a 50 hp Tornado with an uncowled engine performing that well. The MKiii is side by side. Here is an Rans S-12 (side by side) with a uncowled Viking 90 and at the 4:50 mark he talks about cruising 80 on a draggy frame.Right. Looks like some Tornados are cowled, some not. This one says cruise at 75kts. http://lightsportaircraftpilot.com/titan_tornado_experimental_aircraft/pictures.html
They are all tandem, I think. A big advantage.
Thats why I mentioned VGs on the belly as a simple test to confirm where the problem area is located.I think I may have been wrong about the new rear cowling making it better. It may actually be the problem.
Turn the aircraft sideways and look at the fuselage. Its a very thick and stubby double sided airfoil. But what is even more important is that the wing acts as a "fence" on one side, and the other side has the airfoil shaped belly and landing gear fairings on the other end.
So the rear of the fuselage is like a 3 sided airfoil with a fence on one end. There is no way for the low pressure to be relieved.
This usually isnt a problem because a tapered rear usually has open space above and below on most aircraft that use it, which allows air to flow in and reduce the low pressure field on each side. But in this design the wing and the bubble belly are stopping the low pressure from getting relief air from above and below.
The question now becomes how to dissipate it. Because if its dissipated off center this creates lateral flow and a vortex. In fact, with the landing gear mount sticking into the low pressure area and disturbing it, it very well may be the source of the unusually high control buffeting.
I would really love to see some smoke generators mounted just behind the cockpit doors and belly, and see what that flow is doing. In fact, it can probably just be done from the window by a T shaped tube. That would give us some definitive answers to what the flow is actually doing, instead of guessing.