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Well you evidently know what your talking about. Do you know why the Hellcat, Corsair and P47 would all have such different props when they are all large, heavy fighters, all 3 have the same basic engine and all 3 started out with 2000 hp? I can't see why all 3 wouldn't have the same prop.
If I remember correctly the fewer the blades the more efficient the propeller. I think I read that the most efficient propeller was a single bladed counterbalanced propeller, which has never been used for obvious problems.
If I remember correctly the fewer the blades the more efficient the propeller.
This is what my ex-BAe aerodynamicist ex-father-in-law told me on the subject once.
I was wondering why modern prop planes all seem to be going for the multi-bladed cutlass shaped props and how come if this was the best solution it wasn't seen before, esp in WW2.
Advances in materials is a part of the answer I gather too but from his answer I took it that those who worked to more 'pure' aerodynamic teaching would have a natural inclination to prefer as few blades as possible.
Well you evidently know what your talking about. Do you know why the Hellcat, Corsair and P47 would all have such different props when they are all large, heavy fighters, all 3 have the same basic engine and all 3 started out with 2000 hp? I can't see why all 3 wouldn't have the same prop.
Why different props? Different constraints on diameter.
I did prop aero for a few years. There are a lot of reasons why somebody would chose 3 vs 4 blades, including available diameter. Here's some tradeoffs:
Advantages of more blades:
> With more blades, you reduce the induced drag losses
> The individual blades are smaller and lighter
> Since the blade chords are smaller, the forces that the pitch change system needs to provide are smaller.
Disadvantages:
> The dimensions of the blade roots are dictated by vibratory loads during take off (much of the blade is stalled); this means that there is the possibility of choking in the blade roots (this is, iirc, not a problem with fewer than seven or eight blades, and only at flight speeds of about M=0.7 and up.
> More blades are more expensive, as the cost of the individual blade is more a function of blade span than of area.
> More blades means that more parts are needed.
Didn't the early Corsair and Hellcat have to power to spin a 4 blade prop? Wouldn't it have added performance?
I see a lot of High tech and Historival facts on the F4U-4 on when and why the 3 blade or 4 blade prop, Having served with both I won't try and give all the High Tech on the reason why other than the term of Power loading, Also some facts are off on here, the F4U-4 in Korean war had 3 blades but the F4U-5NL had 4 blades, I was Fight deck AB and was close and personal with them both.Didn't the early Corsair and Hellcat have to power to spin a 4 blade prop? Wouldn't it have added performance?
I see a lot of High tech and Historival facts on the F4U-4 on when and why the 3 blade or 4 blade prop, Having served with both I won't try and give all the High Tech on the reason why other than the term of Power loading, Also some facts are off on here, the F4U-4 in Korean war had 3 blades but the F4U-5NL had 4 blades, I was Fight deck AB and was close and personal with them both.
Click o any of the Carriers of Korean war, Uss Princeton, Uss Boxer, Uss valley Forge ect. most had 4 blades but at very beginning in 1950 and 51 there are 3 baled as we used ww2 corsairs, The Marines had some 3 bladed ones also,,Welcome to the board.
A question - would you be so kind to post the Korean war-era photos of the F4U-4 that might show the prop nicely, since I have hard time to pinpoint the F4U-4s with 3-bladed prop? Thanks
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Click o any of the Carriers of Korean war, Uss Princeton, Uss Boxer, Uss valley Forge ect. most had 4 blades but at very beginning in 1950 and 51 there are 3 baled as we used ww2 corsairs, The Marines had some 3 bladed ones also,,
As i said the 3 Blade was beginning of war and the Marine on their carrier like the CVL and CVE, I know the F4U 5 NL was four Blade props I cranked a few and directed and fueled a few, Look up Lt Guy Bordelon Only Korean war Navy ace , he was flying a night fighter F4 U 5 NL,, I was there to help him out of cockpit and at his award ceremony. The replica of his plane is in museum, but the original is in scrap heap in Korea, That too can be Googles'Most had 4 blades' statement is in collision with 'Also some facts are off on here, the F4U-4 in Korean war had 3 blades but the F4U-5NL had 4 blades' statement.
The pictures show predominantly 4-bladed props on the -4, on Boxer and Walley Forge.
I am not sure your motive here for question,, Maybe you don't accept my word,, if so like I always told my sailors, don't ask the dam question if you don't like the answer.lolAs i said the 3 Blade was beginning of war and the Marine on their carrier like the CVL and CVE, I know the F4U 5 NL was four Blade props I cranked a few and directed and fueled a few, Look up Lt Guy Bordelon Only Korean war Navy ace , he was flying a night fighter F4 U 5 NL,, I was there to help him out of cockpit and at his award ceremony. The replica of his plane is in museum, but the original is in scrap heap in Korea, That too can be Googles