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#1
posted to alt.sailing.asa,rec.boats.cruising,uk.rec.sailing
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Wilbur Hubbard wrote:
Among other things, they claim to be able to create something from nothing. The advert states, "Even in dead air the apparent wind when motorsailing generates lift and reduces the amount of engine power needed to maintain the same speed the engine would produce on its own." Huh? Tell me I ain't dreaming . . . You're not dreaming, they're right and you don't understand physics. Is there any more help that you need? |
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#2
posted to alt.sailing.asa,rec.boats.cruising,uk.rec.sailing
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"Steve Firth" wrote in message .. . Wilbur Hubbard wrote: Among other things, they claim to be able to create something from nothing. The advert states, "Even in dead air the apparent wind when motorsailing generates lift and reduces the amount of engine power needed to maintain the same speed the engine would produce on its own." Huh? Tell me I ain't dreaming . . . You're not dreaming, they're right and you don't understand physics. Is there any more help that you need? I had the utmost confidence that the post would usher forth the Looney bin, perpetual motion crowd! Welcome, to you, sir. It's good to see a Brit is the first to insert his foot into his mouth. Wilbur Hubbard |
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#3
posted to alt.sailing.asa,rec.boats.cruising,uk.rec.sailing
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Wilbur Hubbard wrote:
"Steve Firth" wrote in message .. . Wilbur Hubbard wrote: Among other things, they claim to be able to create something from nothing. The advert states, "Even in dead air the apparent wind when motorsailing generates lift and reduces the amount of engine power needed to maintain the same speed the engine would produce on its own." Huh? Tell me I ain't dreaming . . . You're not dreaming, they're right and you don't understand physics. Is there any more help that you need? I had the utmost confidence that the post would usher forth the Looney bin, perpetual motion crowd! Welcome, to you, sir. It's good to see a Brit is the first to insert his foot into his mouth. Well, perhaps the idea is that when sailing into a "dead" wind, the sails be set horizontally, so that the lift generated by them is in the direction which is traditionally associated with "lift", i.e. "up". Like hydrofoils, these aerofoils would cause the hull to ride a fraction of an inch higher in the water, reducing water resistance. Alternatively, the idea might be to back the sails, which would generate a sideways force on the boat, so that it actually travels with some leeway. If the leeway angle is big enough, and the drag from all this doesn't slow down the forwards speed much, the effective speed will be enhanced by the Pythagoras effect. The helm must be instructed to steer a few degrees off the intended destination, to compensate for this beneficial leeway. |
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#4
posted to alt.sailing.asa,rec.boats.cruising,uk.rec.sailing
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Wilbur Hubbard wrote:
It's good to see a Brit is the first to insert his foot into his mouth. Ah no, that would have been you, as usual, Craptain. I bet you think that ice yachts can't reach 146mph either. |
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#5
posted to alt.sailing.asa,rec.boats.cruising,uk.rec.sailing
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Steve Firth wrote:
Wilbur Hubbard wrote: It's good to see a Brit is the first to insert his foot into his mouth. Ah no, that would have been you, as usual, Craptain. I bet you think that ice yachts can't reach 146mph either. Wilbur seems to have it right this time. Either the article is misquoted, very badly written, or just plain wrong. An apparent wind from dead ahead can add nothing but a force directly astern. The case where a true wind from ahead can be used to drive a windmill that can drive a propeller to propel the vessel is different; but this requires a true wind. BTW ice yachts cannot make 146mph *directly* upwind. Andy |
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#6
posted to alt.sailing.asa,rec.boats.cruising,uk.rec.sailing
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On 14 Oct, 14:17, Andy Champ wrote:
An apparent wind from dead ahead can add nothing but a force directly astern. The case where a true wind from ahead can be used to drive a windmill that can drive a propeller to propel the vessel is different; but this requires a true wind. Care to explain why a windmill which is capable of powering itself forward against it's own drag can only do it with a true wind? How does it know if the wind it is 'feeling' is true or not, it has no concept of true wind which is merely the wind speed and direction at an arbitary stationary point. As far as the windmill is concerned it has a 20kt headwind and (alledgedly) it can take that energy, use some of it to hold itself stationary against the wind and _still_ have surplus energy to drive forwards. If it can do that you could gear it to the engine of the 20kt powerboat and save petrol equivalent to the surplus power that is left over once you subtract the energy required to overcome the windmill's own drag from the total energy harnessed by the windmill. |
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#7
posted to alt.sailing.asa,rec.boats.cruising,uk.rec.sailing
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toad wrote:
On 14 Oct, 14:17, Andy Champ wrote: An apparent wind from dead ahead can add nothing but a force directly astern. The case where a true wind from ahead can be used to drive a windmill that can drive a propeller to propel the vessel is different; but this requires a true wind. Care to explain why a windmill which is capable of powering itself forward against it's own drag can only do it with a true wind? How does it know if the wind it is 'feeling' is true or not, it has no concept of true wind which is merely the wind speed and direction at an arbitary stationary point. As far as the windmill is concerned it has a 20kt headwind and (alledgedly) it can take that energy, use some of it to hold itself stationary against the wind and _still_ have surplus energy to drive forwards. If it can do that you could gear it to the engine of the 20kt powerboat and save petrol equivalent to the surplus power that is left over once you subtract the energy required to overcome the windmill's own drag from the total energy harnessed by the windmill. MY recollection of this is that with a windmill it's simply not possible to reduce the drag sufficiently to get a sufficient energy to make it useful. Wingsails are much better at it or even even proeprly trimmed sails. ASCII news isn't the best medium to get the point across, but I'll try. If one is motoring in a calm on a flat millpond then there is an apparent wind equal to the speed of the boat from dead ahead. Hoist a sail and you can make no use of that wind, agreed. However that only applies if you maintain the same course. Now do what any sensible bloke would do and adjust your course to make use of the wind as well as the motor. You now have wind in your sails and you still have an apparent wind. If you look at the force triangle there is still a component from the apparent wind. No doubt the craptain also doesn't beleive in back EMF or any of the other phenomena which appear to produce "something from nothing" however it's not the case that something is being produced from nothing and in this case the extra energy is achieved at the usual expense of not being able to sail directly into the apparent wind. |
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#8
posted to alt.sailing.asa,rec.boats.cruising,uk.rec.sailing
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On 14 Oct, 15:28, (Steve Firth) wrote:
If one is motoring in a calm on a flat millpond then there is an apparent wind equal to the speed of the boat from dead ahead. Yet you've just twice denied that to be the case: "Nor in the case of the motorsailer will the apparent wind be from dead ahead." "they're right and you don't understand physics. " If you must troll pick a consistent line of argument. |
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#9
posted to alt.sailing.asa,rec.boats.cruising,uk.rec.sailing
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On 14 Oct, 15:28, (Steve Firth) wrote:
If one is motoring in a calm on a flat millpond then there is an apparent wind equal to the speed of the boat from dead ahead. Hoist a sail and you can make no use of that wind, agreed. However that only applies if you maintain the same course. Now do what any sensible bloke would do and adjust your course to make use of the wind as well as the motor. Umm. What happens to the apparent wind from dead ahead when you turn and make "dead ahead" a different direction? Ian |
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#10
posted to alt.sailing.asa,rec.boats.cruising,uk.rec.sailing
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"Steve Firth" wrote in message ... toad wrote: On 14 Oct, 14:17, Andy Champ wrote: An apparent wind from dead ahead can add nothing but a force directly astern. The case where a true wind from ahead can be used to drive a windmill that can drive a propeller to propel the vessel is different; but this requires a true wind. Care to explain why a windmill which is capable of powering itself forward against it's own drag can only do it with a true wind? How does it know if the wind it is 'feeling' is true or not, it has no concept of true wind which is merely the wind speed and direction at an arbitary stationary point. As far as the windmill is concerned it has a 20kt headwind and (alledgedly) it can take that energy, use some of it to hold itself stationary against the wind and _still_ have surplus energy to drive forwards. If it can do that you could gear it to the engine of the 20kt powerboat and save petrol equivalent to the surplus power that is left over once you subtract the energy required to overcome the windmill's own drag from the total energy harnessed by the windmill. MY recollection of this is that with a windmill it's simply not possible to reduce the drag sufficiently to get a sufficient energy to make it useful. Wingsails are much better at it or even even proeprly trimmed sails. ASCII news isn't the best medium to get the point across, but I'll try. If one is motoring in a calm on a flat millpond then there is an apparent wind equal to the speed of the boat from dead ahead. Hoist a sail and you can make no use of that wind, agreed. However that only applies if you maintain the same course. Now do what any sensible bloke would do and adjust your course to make use of the wind as well as the motor. Doesn't the wind still appear to come from dead ahead? Or does your motion cause the wind to blow? You now have wind in your sails and you still have an apparent wind. If you look at the force triangle there is still a component from the apparent wind. No doubt the craptain also doesn't beleive in back EMF or any of the other phenomena which appear to produce "something from nothing" Back EMF actually works to negate the driving field to zero or to its initial condition. It's more like "nothing from something". however it's not the case that something is being produced from nothing and in this case the extra energy is achieved at the usual expense of not being able to sail directly into the apparent wind. Yes, and the extra energy from back EMF is not usuable either because it is cancelling the driven field. With logic like yours we are only steps away from perpertual motion. Just think of all the extra energy generated by friction - it's "free energy", if only we can redirect it along the applied force we would have all the energy problems solved. Perhaps if one runs or drives in a zig-zag or back and forth motion we can trick friction into going in our favor - just like you do with apparent wind in sails. You whole argument and reasoning is just that - wind in sails. Wilbur Hubbard's mind is not cluttered with useless memorized facts or dimmed with fuzzy thinking. Basic principles and a strong application of rigorous logic brings correct and defendable conclusions. |
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