I just read the newest FLYING mag and I was really exited about it.
At 50% dia of the prop of the fuse dia the tractor and pusher are even in efficiency. At 60% fuse thickness the pusher looses 3% and at 70% thickness pusher looses 8 %.
Good thing about pushers is that they can be made lot more aerodynamical and slimmer than tractor pulling versions. You can clearly see this at my presentations earlier.
It also says Push Pull Cessna actually climbs 300 ft per minute at pusher prop and 200 with front prop running...this was explained due to better drag separation due to rear prop alone running. This is also good news for my unlimited racer.
This could also explain why ( 30% thicker fused than Max III ) Bede-5B actually needed 14 hp more than AR-5 to go just few mph faster than AR-5. Fuse dia and thickness has a big role in pusher technology and the prop/fan design. Evident in the Peter Garrison story too. He points out that Reymar and several other teachers have teached these aspects.
2009-06-02
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