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Daggerboard position: Maneuverability VS. Acceleration
- Thread starter hashtag_laeuft
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Loading the rudder a lot Upwind with the force of the Sails is not bad, but good
A different issue is a rudder loaded by the HydroDynamic Yaw Moment of the hull, this is dangerous Downwind with large waves ... and even Upwind
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Valkyrie II, the victim of The Satanita
The Satanita - Wikipedia https://en.m.wikipedia.org/wiki/The_Satanita
Roll --> Pitch --> Yaw
HydroDynamic Yaw Moment of the Hull
+
the Wind Force by its Leverage arm (= sine of the Angle of heel x vertical distance between the wind force and the lateral force of the water)
threw the yacht against Valkyrie, sinking Valkyrie and killing a crew member
A different issue is a rudder loaded by the HydroDynamic Yaw Moment of the hull, this is dangerous Downwind with large waves ... and even Upwind
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Valkyrie II, the victim of The Satanita
The Satanita - Wikipedia https://en.m.wikipedia.org/wiki/The_Satanita
Roll --> Pitch --> Yaw
HydroDynamic Yaw Moment of the Hull
+
the Wind Force by its Leverage arm (= sine of the Angle of heel x vertical distance between the wind force and the lateral force of the water)
threw the yacht against Valkyrie, sinking Valkyrie and killing a crew member
The striking thing about this story is that it is a problem that appears in 1880-1890 and that appears again in 1980-1990
Let's remember Hiscock's first sailboat, Wanderer I, which was from the end of the 19th century, and then he had a modern sailboat from, say, 1930 that did not have the hydrodynamic problems of the sailboats of the 1980-1990.
Let's remember Hiscock's first sailboat, Wanderer I, which was from the end of the 19th century, and then he had a modern sailboat from, say, 1930 that did not have the hydrodynamic problems of the sailboats of the 1980-1990.
This model, for example, glided like a magic carpet flying over large waves and reaching a top speed of 20 knots, a clear sign that it dissipated the powerful forces of the Sea and the Earth in a good way.
Luckily, the navigator was an old retired sailor known for his precision, so the data from the experiment are good.
From 1979 is the article by professor Kensaku Nomoto of Osaka University, and when Andrew Claugthon got funding (by joining a group that investigated oil platforms) to create Waves it was in the early or mid-80s of the last century.
In short, everything is so disconcerting. The darkness of supertitions seems to be really powerful.
In short, everything is so disconcerting. The darkness of supertitions seems to be really powerful.
The little old modern (1930) boat
There is no mismatch between Center of Flotation, Center of Buoyancy and Center of Gravity
The bow tolerates pitch better
The bow does not produce a lot of High lateral pressure, and the yacht's Yaw moment is not very large.
The stern creates Low pressure, suction, vertical Suction, and the boat Surfs with an adequate Hull Attitude, stern Down; bow Up
There is no mismatch between Center of Flotation, Center of Buoyancy and Center of Gravity
The bow tolerates pitch better
The bow does not produce a lot of High lateral pressure, and the yacht's Yaw moment is not very large.
The stern creates Low pressure, suction, vertical Suction, and the boat Surfs with an adequate Hull Attitude, stern Down; bow Up
My proposal for a modern yacht
Obey the Center of Flotation
Obey the Center of Flotation
Obey the Center of Flotation
And move everything (keel and mast) towards the stern to reconcile with the center of flotation
A bow capable of creating a lot of Lift based on High pressure, and a stern that helps trim the hull bow Up thanks to Low pressure, Suction.
Obey the Center of Flotation
Obey the Center of Flotation
Obey the Center of Flotation
And move everything (keel and mast) towards the stern to reconcile with the center of flotation
A bow capable of creating a lot of Lift based on High pressure, and a stern that helps trim the hull bow Up thanks to Low pressure, Suction.
Upwind
Upwind we have to fit four Forces
1) Force of Sail
2) Force of Keel/Centerboard
3) Rudder Force
4) Hydrodynamic Yaw Moment of the Hull with Heel/Roll and Yaw/Leeway (M, Max Michael Munk Moment aka "Munk Moment")
Max Munk - Wikipedia https://en.m.wikipedia.org/wiki/Max_Munk
Well, let's assume that we have already fitted it, and all the work is done
No
The puzzle is Upwind ... and... Downwind with Waves
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