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Szolack withdrawing from Shootout Action

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Old 10-20-2016 | 02:12 PM
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Originally Posted by 302Sport
The only thing a cat would need to prevent a blowover would be a hydraulic spoiler on the deck of the boat, just behind the leading edge of the tunnel. It would deploy incrementally as the bow of the boat rises.

I know pretty much everyone on here has flown a commercial airline and seen those big flaps that raise up on the top of the wing. They are designed to kill lift. I linked a slow motion video:

https://en.wikipedia.org/wiki/Spoiler_(aeronautics)

https://www.youtube.com/watch?v=MOHG82Urj2Y
A cat does not have an airfoil. It does not produce lift like an airplane wing airfoil. It relies on the forced air thru the tunnel which is compressed to create lift at the rear of the vessel, similar to an airplane experiencing ground effects, not airfoil lift. Once the attitude of the hull is great enough that the air it is encountering (plowing thru it, like a kite) exceeds the downward force of gravity, the hull behaves like a kite...Without a "string" to resist the force of the air, a blow-over occurs. At that point, disturbing the airflow over the hull or relieving some pressure has little or no effect on the result.
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Old 10-20-2016 | 02:40 PM
  #132  
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I get what you are saying. That is why I am saying that the spoiler would open gradually and most likely a tiny bit under normal operation, like when a big wave is hit and the bow comes up a couple of feet. The comuter would fully deploy the spoiler before the angle of attack was so great that the boat was to that kite point. Also, the spoilers on the aircraft are fully deployed as soon as the aircraft has WOW and are used to plant the aircraft to the runway, when it is in ground effect.

Think about how often somebody works their throttle hand in rough water, that is how i am saying this spoiler would operate, probably every couple of seconds in normal operation but would only fully deploy to prevent a blowover. A canard could basically do the same thing and also give you positive lift when needed, plus be programmed to get the boat at the perfect attitude every single time it is run, but at what point do these not become boats and more along the lines of a WIG.
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Old 10-20-2016 | 02:42 PM
  #133  
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I think Ron's decision is great and hope more follow. I don't think the shootout events will go away one way or the other. I am sure the manufacturers are discussing what has happened this past year and what if anything could have prevented the accidents.Whether changes are made or not there is always the chance of an accident in the boating world. RIP to those we have lost.
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Old 10-20-2016 | 03:00 PM
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Originally Posted by Taboma
A cat does not have an airfoil. It does not produce lift like an airplane wing airfoil. It relies on the forced air thru the tunnel which is compressed to create lift at the rear of the vessel, similar to an airplane experiencing ground effects, not airfoil lift. Once the attitude of the hull is great enough that the air it is encountering (plowing thru it, like a kite) exceeds the downward force of gravity, the hull behaves like a kite...Without a "string" to resist the force of the air, a blow-over occurs. At that point, disturbing the airflow over the hull or relieving some pressure has little or no effect on the result.
That's why a large portion of the tunnel roof needs to pop up in front of the windshield. Hinged up at the front of the boat.
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Old 10-20-2016 | 04:17 PM
  #135  
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A spoiler or flap cannot offset the tremendous wind force under the boat once it starts to lift. Maybe a parachute would work but it would need to deploy very fast.
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Old 10-20-2016 | 04:30 PM
  #136  
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Originally Posted by thirdchildhood
A spoiler or flap cannot offset the tremendous wind force under the boat once it starts to lift. Maybe a parachute would work but it would need to deploy very fast.
Would anyone familiar with aerodynamics care to comment on this?
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Old 10-20-2016 | 04:43 PM
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Originally Posted by hogie roll
That's why a large portion of the tunnel roof needs to pop up in front of the windshield. Hinged up at the front of the boat.
OK, Try to throw an arrow, feather side first. What happens? It will quickly switch to the point (heavy end) first. A boat, cat especially has, as does an arrow, a very high rear polar moment of inertia. Once the bow is up, even with a large hole in the tunnel, it is going to swap ends quickly. Also note that as the bow heads skyward, the effect of gravity holding it down diminishes by the square of the angle to level of the hull. Once all this starts, there is not much one can do to stop it without moving mass to the front very quickly (faster than can be accomplished realistically) or throw an anchor off the back (parachute) to counteract the physics involved in the dynamic sequence of events in a blow over. Question is... what triggers the chute and at what time???
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Old 10-20-2016 | 04:53 PM
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Copelands Phenomenon was fitted with a frontal wing...wasn't that built/designed by a military aero guy/group

http://www.copelandsphenomenon.com/pheno1.htm
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Old 10-20-2016 | 05:16 PM
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All it would have to do is prevent reaching the extreme angle of attack of the whole boat.
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Old 10-20-2016 | 05:41 PM
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Originally Posted by Taboma
At that point, disturbing the airflow over the hull or relieving some pressure has little or no effect on the result.


And at this point in time one's azz ends up in the drink. Having been in this spot myself, the speed at which one enters the drink has all to do with whether one comes out or not.

I have all the sympathy one can have for those involved here, their loved ones as well. The simple fact is that chit happens. simple as that, Chit happens!
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