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Old Nov 29, 2012, 06:24 PM
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Thousand Oaks, CA
Joined Mar 2004
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Everywhere? Not quite. My post above explains why sawtooth/slotted props have virtually no useful benefits for any application -- except where efficiency can be traded for max thrust. This is a very rare occurrence as efficiency is almost always the ultimate goal of any design. For example, to increase max thrust of a cargo plane one would simply increase the propeller efficiency.

One example of an unusual situation where this tradeoff may be valuable is F5B where the propeller is stalled and the motor is cold at launch. So for that first second of flight, you can afford to heat the motor at a higher rate (low efficiency) in exchange for the much greater thrust provided by a non-stalled prop. So it's conceivable that a prop of this type could provide enough benefit during launch to overcome the drawbacks during the rest of the flight. Due to the very extreme aerodynamics involved in semi-stalled near-transonic propellers this is nearly impossible to analyze computationally and even more difficult to test so we may never know if it has any merit or not, but it's conceivable.
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