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| | The Innovation Network Network is not currently active and cannot accept new posts | | On fins and nuclear powered ships | Views: 644 | | Nov 15, 2009 1:36 pm | | On fins and nuclear powered ships | # | 
Ken Hilving | | The discussion on the more efficient blade based on the humpback whale's fin and the kayak tangent has me wondering.
Nuclear powered submarines and surface ships use steam turbines to power propellors. There are advantages to steam turbines over steam pistons, but rapid torque is not one of them. The dual powered stroke of a steam piston seems a better match for the pedal powered kayak where the strokes are converted to flapping fins. A steam piston engine can also use a lower pressured steam.
Assuming the flapping fin propulsion from nature is more efficient and quieter than a propellor drive, using such an approach might make sense for ships. Nuclear powered steam would be the power source, and a steam piston engine might be the better design. The rapid availability of torque would allow the vessels to go from still to speed much like fish and aquatic mammals, certainly an advantage for military vessels and useful perhaps to commercial shipping.
The marlin is the fastest swimmer, and it uses a single fin approach for power. This might be another source of innovation for powering ships, still moving towards a flapping versus rotary propulsion design.
Further mimicking might address maneuverability issues. Fish seem pretty good at direction change, acceleration, and deceleration.
Why stick with nuclear power? It is a proven approach for ships. The steam piston might reduce the size of reactors necessary. Private Reply to Ken Hilving | | Nov 15, 2009 9:42 pm | | re: On fins and nuclear powered ships | # | 
Ron Sam | |
Regarding nature design v. man made:
Design in nature will always exceed man made.
Marlins, dolfins, whales, utilize impulse power through the shape of their body in reaction to the surrounding currents of seawater and flex and torque their body to maximize or optimize how they propel through the water. Just look at Michael Phelps body in a dive underwater to see him flex his body for stretching into the front of opponents to see what I'm talking about.
Perhaps in the future not only will nuclear powered vessels be the standard but ships hulls that are able to shape shift with a complex control processors that takes into account every minute fluctuations in the currents and makes instantaneous reactions to the shape-shifting hull will come about.
RonPrivate Reply to Ron Sam | | Nov 20, 2009 4:20 pm | | re: On fins and nuclear powered ships.. and flaps | # |
abbeboulah | | This interesting item about the humpback whale fins got me to thinking about applying such bumps to an idea I have mulled about for some time, (and was going to try out myself as soon as I grow up enough to get myself a trailer to put my old dinghy in the water again). I put this idea out for free use by anybody who wishes to pursue it, even though Abbé Boulah's attorney suggested I should try to patent it (of course I'd have to pay him...) The idea is this: apply a flap or series of flaps to the bottom of the boat that respond to the varying pressure exerted on the boat by waves in the following manner: when the waves lift the vessel (or the part of the boat where the resp. flap is located, reducing the pressure on the hull in that area, it opens up valves that take in water from the sides. When the waves push the boat deeper and exert more pressure on that part of the hull, the side valves are closed and the water is pushed out through valves or jets aiming backwards, thus exerting a forward push, in addition to any force that may already drive the vessel forward, or -- in the absence of such forces, pushes the boat forward by the wave action only. Sorry, it won't work in the doldrums -- unless you make waves by jumping up and down in the boat, but that is again limited to vessels considerably smaller than aircraft carriers. What's wrong with my reasoning about this?
Private Reply to abbeboulah | | Nov 20, 2009 5:50 pm | | re: re: On fins and nuclear powered ships.. and flaps | # |
Ken Hilving | | I think the problem is with waves lifting the boat. Seems to me that the boat floats on the water, and the waves are really just raising and lowering the water level. As a result, there is very little additional pressure from wave action.
Where the waves might be harnessed is with a stationary platform, like a pier, anchored below the crest of waves. This would allow your flaps and jets to harness the wave movement. Private Reply to Ken Hilving | | Nov 20, 2009 11:50 pm | | re: re: re: On fins and nuclear powered ships.. and flaps | # |
abbeboulah | | You are assuming that the waves lift the boat evenly, which is not at all what happens in reality, especially if the boat already has some motion, and the more weight it has relative to the mass of the wave. The difference in pressure between the front of a boat encountering a wave and, say the middle where it is in the through, is considerable. It accounts for the phenomenon of boats actually breaking up (as has happened in at least one Americas cup race) and boats 'sailing under' at 'hull speed', when the wavelength of the wave equals the vessel hull length: the pressure of the boat itself (plus whatever wind load there is) forces the front of the boat into and under the next wave, pushing under for good. If I ever get my boat out again, I'll invite you out with me to experience it. You'll get wet. You are right though that a lever off a stationary fulcrum will exploit the wave action more efficiently. But then it doesn't go anywhere... Private Reply to abbeboulah | | Nov 21, 2009 2:52 am | | re: re: On fins and nuclear powered ships.. and flaps | # | 
Thomas Holford | | Thorbjoern sayeth:
> What's wrong with my reasoning about this?
I can't say that I can find fault with your reasoning. Based on my fuzzy grasp of the concept, I would imagine that the amount of propulsive force would be quite small.
Nonetheless, even a small autonomous and controllable propulsive force might be useful for some application. I can imagine, for example, a small, unmanned ocean buoy with a propulsion system as you describe which can migrate a mile or two a day to track the weather, follow migrating fish, whales, jellyfish, or whatever.
T. HolfordPrivate Reply to Thomas Holford | | |
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