Is a boat pushed or pulled by the prop.......that is the question

[tlandauer]

With out going back to the debate, the gap on the flex between the drive dog and the strut/stinger has very little to do with where the force is, in today's hi power set up,the twisting torque alone is enough to wind up the cable thus shortening it.

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[markwithak]

your right on wind up but for the life of me can't see why this was even a topic. shaft in front its pushing shaft behind its pulling that's as simple as I could get. Now I am going to leave this allllloooonnnnneeeee...

[raptor347]

The pushing work is being done by the pressure (back) face of the blade. In our application there is very little/no suction happening on the front face due to aeration as the blade enters the water. If the front side doesn't aerate properly and allows the water to stay attached to the front face, you see a huge increase in load with no performance increase. You want air to efficiently fill the void on the suction side as the blade enters the water.

So the question to ponder now is: How do you sharpen the leading edge to maximize aeration and what effect does it have on lift and cavitation? The follow up to that is: Do different hull types perform better with different leading edge treatments?

[tlandauer]

The pushing work is being done by the pressure (back) face of the blade. In our application there is very little/no suction happening on the front face due to aeration as the blade enters the water. If the front side doesn't aerate properly and allows the water to stay attached to the front face, you see a huge increase in load with no performance increase. You want air to efficiently fill the void on the suction side as the blade enters the water.

So the question to ponder now is: How do you sharpen the leading edge to maximize aeration and what effect does it have on lift and cavitation? The follow up to that is: Do different hull types perform better with different leading edge treatments?

Thanks! Food for thought!!