ORIGINAL: pe reivers
Hey guys!
This discussion has nothing to do with the OP question.
Since we do not use oversquare props, blade stalling is a non-issue here, and a can of worms better left closed. All analogies don't help much in understanding, and just try to explain what happens without exactly knowing what happens. There is good software (free) out there that shows what higher pitched blades mean to prop thrust and prop disk airspeed relations. It certainly is not an analogy with a clogged vacuum cleaner (with a radial pump). That device follows quite a different set of rules.
For the most part I thought the OP's question was answered and was happy at post 17 so I threw in a stimulating subject. But back to the OP's original post, he stated he was turning a Top Flight 15X6 @ 9150 and he was getting 7 pounds of thrust with his fish scale, however the calculator shows 10.49) pounds static thrust (#3 bulky plane). That's quite a discrepancy, do you think he may need a better fish scale?
We do use a lot of square and over square props, APC sells a heck of a lot sizes of those in pattern, pylon and sport props. Granted, not as many of those are sold as say an 11X6.
The Gyles calculator looks like it's exactly what I was looking for but it doesn't seem to work, at least on my computer, does anyone else have the problem? There may be a problem with that site.
Yes a vacuum cleaner (axial/centrifugal impeller) follows a different set of rules, but it got my point across to MJD...I think anyway. I have momentarily stalled ducted fans with my hands blocking intakes or outlets on both IC and electric, they too speed up.