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Old 23-04-2006, 15:54   #46
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Not crazy, but simply put, you can't easily and cheaply get enough energy back from what you have to put in. Which comes back to the problem of having to plug into shore power which means the energy has to be generated by some other means.
It would be possible if you only ever needed to reverse out of the dock and then put up a sail. But for most of us, we need way more power and for a much longer duration than batteries can produce.

Another idea was the hydrogen fuel cell. But even that isn't clean green either. At the moment, the only way to produce large quantities of hydrogen reasonably economicaly, is to produce it from hydrocarbons, which means vast quantities of greenhouse gasses being released as by products again. So it defeats the purpose. So the idea of "hydrogen highways" being away to reduce emmisions is rubbish. It just shifts the polution from one source to another.
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Old 23-04-2006, 17:38   #47
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Wheels, I've seen these too! (somewhere) Even back in the early 80's, I remember a picture of a boat with a spinning cylinder type mast and no other sail. The cylinder was over sized, and relied on the Bernouli Effect. same as your example. Could produce force in any direction relative to the wind.

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Originally Posted by Alan Wheeler
Not really John. That's because the water is part of the drive train. And it works backwards kinda. In that it actually has the least loss at full speed. So the engine is actually working the hardest at it's maximum RPM. If you slipped it up a gear, the engine would become overloaded. The water acts kinda like a "torque converter" on the front end of an auto gearbox.

Hey guy's, what about wind and sails. No actually I mean more efficiency in this area. I know of a guy that had a cat with a fixed wing type sail on top. The wing could be turned and the entire craft steered by a small joystick. So he could litteraly back the craft out of his birth and then steer it where ever he wanted. Why haven't we seen more of this type of stuff. I know a Ship somewhere has three of theses wing things on top. So what's with the idea. Has it a big limitation or something??
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Old 23-04-2006, 17:47   #48
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Rich,

Sometimes on the forum I may sounds a little LEFT, but I agree with almost everything you say here. These political and economic problems are sending this country to 3rd world status and FAST.

You hit on just about every economic disaster that's heading our way, with the exception of the onslaught of retirees that will be tapping into social security soon.

Now how to escape the impending collapse... that's the real challenge.




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Well DeepFrz
the 1970s oil shocks were totally and artificially instigated by government intereference by 'wage & price controls' that totally upset the demand/supply. And you want 'more' government intereference? ... of the same kind that lead to the not too recent California debacle in power generation costs .... I dont think so.
Petroleum is driving force of the 'world market' and unless the country that you happen to be in is a net exporter of the stuff (surplus of supply, surplus of refining capacity) then you are simply subject to the whims of the world economics; and, no matter what 'governments' think they can legislate or not because government simply dont 'make' petroleum. Its just the simplicity of 'global economics'.

Before China and India needed and competed for 25% of the worlds petro capacity to meet their needs the costs were quite stable. Now that those two entities have essentially reduced that 25% from 'other' countries .... the market prices naturally go up. Thats just simple economics that 'politicians' have NO control, .... other than to make much artificially much worse.
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Old 23-04-2006, 18:14   #49
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Eric Sponberg has designed some interesting boats with rotating, free standing masts. The masts rotate so they are a more efficient part of the airfoil, no matter where the wind.

He has one design where he added a mast to the bow of a Freedom and then added more bouyancy to the bow. The boat apparently sailed very well is is well mannered.

Check out his web site, he has some interesting writeups.
http://www.sponbergyachtdesign.com/Copernicus.htm

I think that the problem with any new mast system is that the racing rules basically forbid them. Then there is the conservativism of the sailing community. There is a modern boat that went with one of the rotating mast systems but it was very heavy so he had to change to a free standing carbon fiber mast. Boat is Barbara-Anne

http://www.coveyisland.com/b-a.html
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Old 23-04-2006, 18:24   #50
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Richhh,

wasn't the problem with California energy caused by the state selling off the power generation to a private company that then defrauded the people of CA? I seem to remember some company (was it Enron?) was charged in the matter. Probably still in the courts. Of course you wont hear about that on Fox news, will you?

I don't want government interference. It would be nice if private enterprise could be trusted to "do the right thing", then we wouldn't need all these rules and regulations.

About atomic energy. Three mile island was a fart in the wind. Chernobyl now, that was a disaster.

Phil
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Old 23-04-2006, 18:32   #51
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Richhh & DeepFrz.

We started this thread off as a way to collect ideas to possibly come up with ways for new sailboat propulsion. Not start a political rant here!!

Kai Nui, himself did not start this thread to become a political 3 ring circus!!

Could we "PLEASE" stop this government conspiracy garbage. It's been said & done!! So lets leave it there!!
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Old 23-04-2006, 18:54   #52
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okay...
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Old 23-04-2006, 19:02   #53
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Ok?
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Old 23-04-2006, 19:09   #54
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DMan, I am all for electrical propulsion, but it is far more problematic than increasing the efficiency of an internal combustion engine. I am happy to reinvent the wheel if that can be done, but I do not have any ideas on how to do it. Rotary diesels have shown quite a bit of potential if you believe the sale pitch. Has anyone had any experience with these engines? A link posted earlier (or maybe it was on the fuel prices thread?) rates the efficiency of hydrogyn as a power source. The bottom line was 47% efficiency as compared to fossil fuels at 14%-16%. What this means is to develop an internal combustion engine that is as efficient as hydrogyn the efficiency will need to increased by at least 300% of it's current efficiency. For the average small auxillary diesel, consumption would have to be reduced to approx 125 milliliters per hour. So... Can this be done?
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Old 23-04-2006, 20:07   #55
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Well, if you are looking to reduce reliance on the diesel engine for
everything
save propulsion, a very efficient engine is the Stirling Air engine. While it could probably never develop the power to drive a vessel IRT, the poser generated by it could be battery stored and use an electric engine.
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Old 23-04-2006, 20:53   #56
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That is part of the problem. I would not want to reduce the usefulness of the engine. While a set of sweeps and a couple of solar panels will solve most of the issues, sometimes it is a good thing to be able to motor against the current.
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Old 23-04-2006, 21:26   #57
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Size limitations is not the issue with a stirling engine, it is the fact that most of the energy is still heat. The ability to produce mechanical motion is a by product of the heat. With a combustion engine, the mechanical motion is the first and formost energy, and heat is a smaller byproduct.

Kai, can you direct me to some articles on a Diesel rotatary so I can read up.
The standard Wankle rotary run on petrol was rather inefficent. It guszzled Gasoline, so I am curiouse as to how it is more efficient with Diesel.
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Old 23-04-2006, 21:57   #58
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Wheels, here is one that was of particular interest to me: http://quasiturbine.promci.qc.ca/EIndex.htm These guys have addressed a number of the issues with the wankel engine. There is another link, http://www.wankel-rotary.com/ that shows some diesel options. The second link is for a multifuel engine. Although it claims to run on diesel, it is not possible to get the 20:1 compression needed to combust diesel, so these engines use a spark to fire the diesel.
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Old 23-04-2006, 22:54   #59
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Quote:
Originally Posted by Kai Nui
DMan, I am all for electrical propulsion, but it is far more problematic than increasing the efficiency of an internal combustion engine. I am happy to reinvent the wheel if that can be done, but I do not have any ideas on how to do it.
There is one major problem with increasing the efficiency of internal combustion engines:

It has already been done.

The engines we use now are the end results of all the major improvements that anybody has been able to think of. Many people would stand to make a lot of money from further improvements, but it is a hard problem. We still see tiny incremental improvements happening, such as from computer control of car engines, but the the big steps have already been taken.


Here are a few other thoughts I have reading this thread:

If a major goal is independence from fossil fuels, you need to find a non-fossil-fuel energy source. Reforming natural gas, coal, or oil into hydrogen is not a non-fossil-fuel energy source.

As mentioned before, hydrogen is not an energy source. You can, however, make hydrogen as a way to carry energy around.

It doesn't really matter how efficient this process is. It matters whether it is economical. For example, suppose it takes 10 times as much energy to make hydrogen for my car as there is in the gasoline it takes to drive the same distance. If I burn gasoline to make the hydrogen, I lose. If I use geothermal energy, the only question is whether the amortized cost of the geothermal plant, hydrogen infrastructure, and hydrogen car is less than the cost of the gasoline, gasoline infrastructure, and gasoline car.

That is, if I spend $20 / week driving to work instead of $40 / week, I come out ahead even if my car can only use 5% of the energy. Of course, this only applies if the car doesn't cost more -- if it costs $50,000 for a hydrogen car and $20,000 for a gasoline car, I will have to get used to paying $5/gallon for gasoline.

The same sort of analysis applies to any proposed system.


Stirling engines lose if your fuel is anything that could burn in an internal combustion engine. That is, you could get more energy out of the same fuel using a conventional engine. This applies whether your fuel is diesel, gasoline, natural gas, propane, hydrogen, kerosene, canola oil, etc. A stirling engine may be a win if you have a large supply of free wood to burn (can't burn wood in internal combustion engines), though you would have to consider whether it would be better to gasify the wood and burn the resulting gas.


You have to consider the whole chain of manufacture of your energy. Ethanol from plant matter and plant oils are non-fossil-fuels, but you have to consider where you get the plants from. If you use petroleum-based fertilizers, you are still using fossil fuels and still contributing to global warming. If you burn petroleum to run the still, you are still dependent on fossil fuels. At least one analysis purports to show that burning ethanol in your car actually uses more petroleum than burning gasoline, because of the petroleum used in the manufacturing and distribution process. (Tax incentives make it economical.)


There, I managed to avoid beating the dead horse.
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Old 23-04-2006, 23:41   #60
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coot, second try here. I just deleted a long post darn! THe efficiency of hydrogyn was discussed in depth on this link posted earlier in this thread
http://www.rmi.org/sitepages/pid985.php
That is where I got my comparitive numbers.
Combustion engine technology is improving, and IMO the rotary diesel shows great promise. A hydraulic drive will decrease friction, and increase efficiency. The 4 faced rotors address the combustion chamber issues that plagued the Wankel design. I am not sure if there is already such a design, but an oil filled encapsulated bearing would decrease friction substantially. Fitting a 4 surface rotary diesel with oil filled bearings, and hydraulicly driving accessories also fitted with oil filled bearings would potentially eliminate almost all of the friction. Only the necessary friction between the rotor and the cylinder would remain. Coupled with the hydraulic drive this should be a far more efficient way to propell a boat.Electronic direct injection and reed valves would further increase the efficiency. FWIW, the 16hp single rotor engine only weighs 76 pounds, so weight savings would also be accomplished. Since the oil filled bearings would be sealed, and could potentially be made of stainless (at least on the non bearing surface) they could also be fitted onto the shaft in place of a packing, further reducing friction. WIth the hydraulic drive, the engine could be designed around a very steep power curve with a 200 or 300 RPM peak, and a sharp drop below and above the peak. This would allow even more efficiency at peak power, as the engine would no longer need to produce usable power throughout the RPM range.
I am fine with using fossil fuels. I would just like to have a substantially greater range on the fuel I have. I would love to see that 125ml per hour number. This would provide about 30 hours per gallon or potentialy 8600 miles on my current fuel capacity.
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