ORIGINAL: Barry Cazier
Is cowl width much of a consideration? On my EF Yak....the 2 blade doesn't stick out past the cowl very much. I'm saying maybe 3-4 inches on both sides. Obviously, a 3 blade (smaller diameter) would stick out less. Is this of any concern that the 3 blade wouldn't make the thrust past the cowl?
Thanks
Barry
Not usually much of a consideration.
If your Yak is an electric, chances are there isn't a 3 blade made in the size you need.
People who've tested 3 blades on their Yaks and Sukhois often wind up flying them. If you can find one to test, it's worth the try.
What is behind the prop, like cowl, has been proven to be whatever problem it would be anywhere on the plane. Being directly behind the prop has never been a big deal. P-47, Corsair, Hellcat, FW190, La-5, Hawker Tempest II and Fury, etc were all exceptionally fast and had big, radial cowls... and multi-bladed props.
Even if you go down 1" in diameter, the blades still reach past the cowl as far minus just 1/2". And with a 3 blader, there is an extra blade to make up for the lack of radius with a whole extra blade of area.