New propulsion sytems for ships

[Vega]

I find this report on oil shortage and future previsions quite interessant:

OIL & GAS 2006: Global Ten-year Projection by Douglas – westwood

A data report available from Energyfiles in association with Douglas-Westwood will revolutionise the analysis of future oil trade balances and potentially rewrite oil price forecasts advocated by such luminaries as the CEOs of Shell and BP. Having predicted, and now witnessed, the first oil price surge Energyfiles has decided to publish its comprehensive ten-year dataset, forecasting oil and gas production, consumption and trade in every producing country in the world.

Energyfiles Director Dr Michael R. Smith, and lead analyst, says "the ten-year data demonstrate that it is no longer appropriate to accept glib demand forecasts from oil companies, financial institutions and governments that predict, with wishful thinking, ever-growing demand levels, contrary to observations on oil supply. Suggestions that oil consumption will grow to up to 120 mm bbls per day by 2020 and that automobile and airline traffic will increase at extraordinary rates are futile and damaging to policy makers."

"Such forecasts, divorced from reality, fail to take account of tight supply conditions and rising prices. We will be unable to produce oil at these rates without unbelievable step changes in technology. After 2010, and for periods before this, oil supply limitations and prices will seriously subdue energy demand unless suitable liquid alternatives are developed."

….."Projections in 'Oil and Gas 2006' are consistent with rapidly rising prices after 2010 accompanied by painful conservation," Smith says. "Sufficient new supplies will not come onstream to replace the inexorable depletion of existing fields,..."

"Until 2010 oil supplies will struggle to keep up with demand causing intermittent upward pressure on prices as the supply/demand ratio swings in and out of balance. After 2010 upward pressure will be permanent. The near term effect on the economies of countries will differ depending on their level of development, location, dependence on imported oil, and availability of other raw energy materials and/or infrastructure to produce fuel alternatives. Gas, the best short-term substitute, will be available only if investment in infrastructure, above all long distant pipelines and LNG conversion and receiving plants, is well advanced".

[gonzo]

The solution and the problem is as much political as technological. As long as we, the public, demand cheap abundant fuel, governments will oblige. I was reading an article in a local newspaper, and it pointed out that most solutions seem to be either/or. There can be a phasing out of cars and mega highways and a development of more mass transportation. With boats it is different, since it is more difficult to justify their necessity. I mean, driving to work in a 4,000 lb SUV by yourself can be rationalized as safety. Driving your 100 Kt rocket at 150 GPH not. The world will change whether we like it or not. It is a golden opportunity for inventors and enterpreneurs.

[Guillermo]

Originally Posted by JonathanCole

....No comments on scaling this up?

1.- Maybe big and slow intercontinental cargo submarines for products not requiring tight-time deliveries?.... Difficult even for commodities, as the market, although allowing for some 'on-board speculation time', asks for quick deliveries once deals are closed....

2.- Stealth automated submarines carrying nuclear weapons, diving slowly and quietly between termoclines in the middle of the oceans, ready to be brought to surface and fired whenever necessary? ....Maybe they exist already...?

3.- Subsurface fuel storing units, hiding between termoclines, ready to refuel military vessels in the middle of the ocean?... Same 2nd question as before.

4.- Same as in point 2, but for spy units.

5.- Whales' migrations observatory?

6.- Captain Nemo's dreamt submarine..?

[JonathanCole]

Originally Posted by Guillermo

1.- Maybe big and slow intercontinental cargo submarines for products not requiring tight-time deliveries?.... Difficult even for commodities, as the market, although allowing for some 'on-board speculation time', asks for quick deliveries once deals are closed....

These gliders use gravity to propel them. The wings give lift and forward movement as the ship dives. Maybe the weight of a big ship would increase the speed of submerging, especially if the ship is very hydrodynamically shaped. Actually the ship can also use its wings to move forward when it is surfacing by means of bouyancy.

[Guillermo]

Originally Posted by JonathanCole

.... The Slocum Glider uses a Webb Research heat engine that draws energy from the ocean thermocline—a layer where the ocean's temperature changes rapidly: it's the boundary between the warmer water above and the cooler waters below. The Slocum Glider cycles thousands of times between the surface and a pro-grammed depth, getting the energy it needs to change its buoyancy from the heat flow of the surrounding water....

Do you know how this heat engine works?

Originally Posted by JonathanCole

...Maybe the weight of a big ship would increase the speed of submerging, especially if the ship is very hydrodynamically shaped...

Well, I just was speculating. Probably these gliders are only good for small units working with no variable cargo. But anyhow something to keep on thinking...

[Guillermo]

More weird propulsion systems:
http://www.rbbi.com/folders/tech/product/penguin.htm
http://web.mit.edu/towtank/www/Tuna/tuna.html

More info or comments on them...?

Interesting:

Review of Fish Swimming Modes for Aquatic Locomotion

[Guillermo]

This seems to be a real alternative to conventional propellers in inland shipping, allowing a 20% gain in propulsion efficiency.

A New Way of Stimulating Whale Tail Propulsion

Whale Tail Wheel Propulsion.

More in Dutch

Anybody has more info on this, please?

Interesting paper:
FANTASIE Deliverable 12

[wet-foot]

hey it looks like an old paddle wheel set-up from a riverboat!!!!!!!

[JonathanCole]

Originally Posted by Guillermo

This seems to be a real alternative to conventional propellers in inland shipping, allowing a 20% gain in propulsion efficiency.

Anybody has more info on this, please?

http://www.nap.edu/openbook/0309058791/html/946.html

Whale tail propulsion gives a much greater surface area but what about the vulnerability to debris?

[kjell]

Now is the time to use Hydrogen as a steam generator. I have had this idea to make a marine pulse thruster. The exhaust from the burned air / hydrogen mix is conducted in the middle of a multi venturi "nozzle" converting the high speed gas in to slow speed water movement. Adapting the pulse frequency to the wave frequency will maybe reduce hull frictions as fishes do.

[marshmat]

Kjell- you might be interested in Pursuit Dynamics' prototype steam/shockwave jet pump, i believe PDX is the series name. Look them up- might give you some more ideas.

[Guillermo]

Good info, marshmat, thanks.
Kjell, could you please more extensively explain your idea?
About marshmat post, have a look at:
http://www.tfd.chalmers.se/~valeri/Ajax/design.pdf
Information there is from 2002. Has anybody heard of further developments/boating applications?

[kjell]

The marine propulsion system I am working with is different to the PDX steam/shockwave jet pump. It is not producing steam. The exhaust from the burned hydrogen/air mix is conducted in the middle of the nozzle.

[marshmat]

Originally Posted by kjell

It is not producing steam. The exhaust from the burned hydrogen/air mix is conducted in the middle of the nozzle.

Kjell, the exhaust from burning hydrogen is steam. The combustion reaction for hydrogen is
2 H2 + O2 --> 2 H2O
If this reaction occurs in air, the end product is a mixture of steam and nitrogen.

[kjell]

[quote=marshmat]Kjell, the exhaust from burning hydrogen is steam.
QUOTE]

-Matt-
You are right. I tried to say that it is not working with a continuo steam supply from a boiler.