Advance Ratios and Gear Ratios

[Zipper730]

I was thinking about something -- to determine propeller tip-speed you'd compute the RPM/60 and then multiply that by the circumference of the propeller, right?

 

[fubar57]

Gooooooogle
Prop tip speed formula

 

[Zipper730]

kmccutcheon , P PStickney , S Shortround6

Several matters...

1. What's the propeller gear-ratios seen on the Griffon's?
2. When factoring in speed it's =SQRT(Tip-Speed)^2+(Forward Velocity)^2) right?

 

[wuzak]

1. What's the propeller gear-ratios seen on the Griffon's?

Which mark of Griffon?

 

[Zipper730]

Did any of them have gear ratios other than 0.451 and 0.5102?

 

[wuzak]

Yes, the contra props had a different ratio.

 

[Zipper730]

Yes, the contra props had a different ratio.

What ratio did the contra-rotating propellers use?

 

[wuzak]

0.4423:1