Senyorita
02-13-2009, 08:43 AM
Guys, any ideas on alternative (say fish-like) propulsion for a small personal submarine?
View Full Version : Fish-like propulsion
Fanie
02-13-2009, 09:30 AM
A fish has very strong muscles it uses to curve the body so that foreward propulsion takes place. This may not be so easy to duplicate to the level where it reaches similar efficiency. The other thing is the speed with which it takes place.
Maybe get the crew big flippers and they can hang in the water and just kick... or advertise...
Vacancy for four kickers, warm water environment, 50% kick duty cycle with TV to help pass the time. But that's not all, if you apply right now a comfy resting chair for in betweens a throwed in as a bonus.
Maybe get the crew big flippers and they can hang in the water and just kick... or advertise...
Vacancy for four kickers, warm water environment, 50% kick duty cycle with TV to help pass the time. But that's not all, if you apply right now a comfy resting chair for in betweens a throwed in as a bonus.
TeddyDiver
02-13-2009, 01:24 PM
Fins and scuba gear :D
JetFins for frog like propulsion, Split fins for sealy and regular for fishy :P
JetFins for frog like propulsion, Split fins for sealy and regular for fishy :P
Petros
02-13-2009, 04:06 PM
biological mechanisms are generally way too complex to make practical in a man made device. It can be done, it is just not easy to duplicate.
Also the wheel or axle is almost non-existent in nature, so you have no examples of naturally occurring propellers. But the so far the most efficient way to convert mechanical power in to fluid propulsion is the propeller, which turns on a shaft.
It was actually this realization, after many centuries of failed attempts, to build a practical man carrying aircraft. To separate thrust from lift, and then develpe differant way of providing them. To many centuries of trying imitate birds resulted in a lot of wasted effort.
It might be a fun experiment, and others have done this, but I am not sure it is practical.
Also the wheel or axle is almost non-existent in nature, so you have no examples of naturally occurring propellers. But the so far the most efficient way to convert mechanical power in to fluid propulsion is the propeller, which turns on a shaft.
It was actually this realization, after many centuries of failed attempts, to build a practical man carrying aircraft. To separate thrust from lift, and then develpe differant way of providing them. To many centuries of trying imitate birds resulted in a lot of wasted effort.
It might be a fun experiment, and others have done this, but I am not sure it is practical.
Fanie
02-13-2009, 04:25 PM
biological mechanisms are generally way too complex to make practical in a man made device. It can be done, it is just not easy to duplicate
I agree, seems the only thing we can get to duplicate is the amuba (that wich some of us think with), slurp spiders and polution. That should cover about everything ;)
Amazingly man claims near life creation with his DNA replication (can we get a perfect woman here please :D) but could not come up with a more efficient form of transportation than telling someone to go to hell :D
Sigh. It seems man has a bit of way to go yet.
If man was as clever as we think we are then -
why aren't we all rich
and why don't we develop all future technologies today
I agree, seems the only thing we can get to duplicate is the amuba (that wich some of us think with), slurp spiders and polution. That should cover about everything ;)
Amazingly man claims near life creation with his DNA replication (can we get a perfect woman here please :D) but could not come up with a more efficient form of transportation than telling someone to go to hell :D
Sigh. It seems man has a bit of way to go yet.
If man was as clever as we think we are then -
why aren't we all rich
and why don't we develop all future technologies today
robherc
02-13-2009, 11:27 PM
A fish has very strong muscles it uses to curve the body so that foreward propulsion takes place. This may not be so easy to duplicate to the level where it reaches similar efficiency. The other thing is the speed with which it takes place.
Hmmm, if a sub were moving itself into the positions a fish does, and at the same (or even similar) speeds, the contents of the sub would quickly turn from A. Human beings, to B. Red, bloody mush.
...just my $0.02
Hmmm, if a sub were moving itself into the positions a fish does, and at the same (or even similar) speeds, the contents of the sub would quickly turn from A. Human beings, to B. Red, bloody mush.
...just my $0.02
Rick Willoughby
02-13-2009, 11:40 PM
Guys, any ideas on alternative (say fish-like) propulsion for a small personal submarine?
A propeller wins out. If anything in the animal world could duplicate a shaft and bearing that animal would use a propeller and would be the fastest and best swimmer of them all.
The wheel and the technology that goes to make it work - the axle and bearing is not duplicated anywhere in nature (at least as far as I know). That is why it is such a significant invention. It is one of the rare instances where nature has not found a better solution.
Imagine if you held the perpetual intellectual property for the shaft and axle and its associated spin-offs such as the wheel.
Rick W
A propeller wins out. If anything in the animal world could duplicate a shaft and bearing that animal would use a propeller and would be the fastest and best swimmer of them all.
The wheel and the technology that goes to make it work - the axle and bearing is not duplicated anywhere in nature (at least as far as I know). That is why it is such a significant invention. It is one of the rare instances where nature has not found a better solution.
Imagine if you held the perpetual intellectual property for the shaft and axle and its associated spin-offs such as the wheel.
Rick W
ancient kayaker
02-13-2009, 11:55 PM
A fish's tail and a boat's propeller do exactly the same thing in exactly the same way, by producing a longitudinal force from a lateral motion, just like a screw thread. In fact ship's propellers are properly called screws. The prop uses a continuous rotary motion, the tail an oscillating one. Experience and theory have both established that continuous motion is more efficient that oscillation. Although a fish tail is remarkably efficient, it has taken millions of years to get that way. The propeller was optimized in far less time.
Having got that off my chest, maybe you're not so much concerned with efficiency as innovation, you asked for ideas after all! There's jet propulsion as used by squids, gas propulsion as used in toy pop-pop boats, flapping wings per the manta ray, and related to that perhaps flexing the sub's sides in a wave motion may generate some thrust.
Having got that off my chest, maybe you're not so much concerned with efficiency as innovation, you asked for ideas after all! There's jet propulsion as used by squids, gas propulsion as used in toy pop-pop boats, flapping wings per the manta ray, and related to that perhaps flexing the sub's sides in a wave motion may generate some thrust.
robherc
02-14-2009, 12:04 AM
Maybe some form of belt drive with semi-flexible "flippers" attached? You could run the belt down the side of the sub like a conveyor belt (one on each side...or better use 3-4 of them for 3 dimensional maneuvering) and have the belt enter a narrow slot that folds the "flippers against the belt for the forward-travel portion of its revolution.
Fanie
02-14-2009, 05:04 AM
Hmmm, if a sub were moving itself into the positions a fish does, and at the same (or even similar) speeds, the contents of the sub would quickly turn from A. Human beings, to B. Red, bloody mush.
I wasn't suggesting ! :D
A fish has the fastest pull away of all animals. It bends it's body and when it goes streight it is on speed. It would probably knock your eyes right to the back of your head :D Unless you are looking aft that is... then you would be looking for them :D
I wasn't suggesting ! :D
A fish has the fastest pull away of all animals. It bends it's body and when it goes streight it is on speed. It would probably knock your eyes right to the back of your head :D Unless you are looking aft that is... then you would be looking for them :D
Fanie
02-14-2009, 05:12 AM
See Petros's post. Copying animal propultions has never been done except running on land, but in the air we cannot flap wings and in the water we cannot swim with fins on our boats.
robherc
02-14-2009, 12:45 PM
Actually, the hobie mirage drive is close to using fins...but it's more like a fish using its pectoral fins to move (they tend to do this when "bored" or "loafing" mainly), NOT like using the tail...but that's about the closest I know of for boat propulsion.
alan white
02-14-2009, 12:47 PM
One fishtail design I tried (in model form) was a flexible (conveyor belting) rudder-like "flag" that was affixed vertically to the end of the boat.
What made it go was at it's aft end and not the leading end.
A rod bent to 90 degrees was affixed to the vertical aft edge of the tail as follows: The horizontal part of the same rod was above water and swung an arc from a pivot above the leading edge of the tail (corresponding with the customary pivot axis of a rudder). The rod ran horizontally back to the bend. Now vertical, it entered the water and the aft end of the tail attached to it.
Here's the trick: The horizontal length of the rod was less than the horizontal length of the tail. Therefore, there was always a sideways "sag" in the conveyor belt tail. This sag could be adjusted while underway as well, but there was always a sag.
The back and forth (like rudder pumping) application of power to the bent rod caused the tail to propel the boat forward, exactly like a fish tail.
This same action can be made to derive power from water or from wind (using sailcloth).
What made it go was at it's aft end and not the leading end.
A rod bent to 90 degrees was affixed to the vertical aft edge of the tail as follows: The horizontal part of the same rod was above water and swung an arc from a pivot above the leading edge of the tail (corresponding with the customary pivot axis of a rudder). The rod ran horizontally back to the bend. Now vertical, it entered the water and the aft end of the tail attached to it.
Here's the trick: The horizontal length of the rod was less than the horizontal length of the tail. Therefore, there was always a sideways "sag" in the conveyor belt tail. This sag could be adjusted while underway as well, but there was always a sag.
The back and forth (like rudder pumping) application of power to the bent rod caused the tail to propel the boat forward, exactly like a fish tail.
This same action can be made to derive power from water or from wind (using sailcloth).
ancient kayaker
02-14-2009, 01:11 PM
I wasn't suggesting ! :D
A fish has the fastest pull away of all animals. It bends it's body and when it goes streight it is on speed. It would probably knock your eyes right to the back of your head :D Unless you are looking aft that is... then you would be looking for them :D
They're pretty quick it's true, but for sheer acceleration over a short distance the squid is tops. Hard to beat jet propulsion.
A fish has the fastest pull away of all animals. It bends it's body and when it goes streight it is on speed. It would probably knock your eyes right to the back of your head :D Unless you are looking aft that is... then you would be looking for them :D
They're pretty quick it's true, but for sheer acceleration over a short distance the squid is tops. Hard to beat jet propulsion.
sigurd
03-06-2009, 09:14 AM
Senyorita,
Do search for ornithopter, MAV (micro air vehicle), flapping wing propulsion.
I think one of the most efficient ways to do it in a sub would be to have two foils, configured like a biplane, flapping up and down, 180' out of phase. This way there is something similar happening as the surface effect - induced drag is reduced if I am not mistaken.
Triangular motion would be more efficient than sinusoidal, I think.
You could use simple NACA0012 foils and you should have an adjustable angle of attack, which reverses for each half stroke. Good luck.
Do search for ornithopter, MAV (micro air vehicle), flapping wing propulsion.
I think one of the most efficient ways to do it in a sub would be to have two foils, configured like a biplane, flapping up and down, 180' out of phase. This way there is something similar happening as the surface effect - induced drag is reduced if I am not mistaken.
Triangular motion would be more efficient than sinusoidal, I think.
You could use simple NACA0012 foils and you should have an adjustable angle of attack, which reverses for each half stroke. Good luck.
Boston
03-15-2009, 05:05 PM
http://www.aitrui.com/1A-Images-Foundation/Art-Images/anim-UFOsouce.gif
Im not going to attempt any arguments for intelligent design ( dam poor excuse for science ) but I would point out that the basic bacterial flagellum fits that description
http://jkellyblog.com/images/videos/bacterial-flagellum.png
also illustrated
http://www2.sad42.k12.me.us/teachers/lowell/7_grade_science/cell/Image5.jpg
Some bacteria boast a marvelous swimming device, the flagellum, which has no counterpart in more complex cells. In 1973 it was discovered that some bacteria swim by rotating their flagella. So the bacterial flagellum acts as a rotary propellor -- in contrast to the cilium, which acts more like an oar.
The structure of a flagellum is quite different from that of a cilium. The flagellum is a long, hairlike filament embedded in the cell membrane. The external filament consists of a single type of protein, called "flagellin." The flagellin filament is the paddle surface that contacts the the liquid during swimming. At the end of the flagellin filament near the surface of the cell, there is a bulge in the thickness of the flagellum. It is here that the filament attaches to the rotor drive. The attachment material is comprised of something called "hook protein." The filament of a bacterial flagellum, unlike a cilium, contains no motor protein; if it is broken off, the filament just floats stiffly in the water. Therefore the motor that rotates the filament-propellor must be located somewhere else. Experiments have demonstrated that it is located at the base of the flagellum, where electron microscopy shows several ring structures occur.
http://www.arn.org/docs/mm/fdsmall.gif
by way of disclaimer some of this info has been used by the nut jobs on the far right to argue intelligent design and although the simple science is pertinent to this discussion I consider its relevance to any arguments concerning space men or gods to be somewhat less than tenable
my two cents
B
Im not going to attempt any arguments for intelligent design ( dam poor excuse for science ) but I would point out that the basic bacterial flagellum fits that description
http://jkellyblog.com/images/videos/bacterial-flagellum.png
also illustrated
http://www2.sad42.k12.me.us/teachers/lowell/7_grade_science/cell/Image5.jpg
Some bacteria boast a marvelous swimming device, the flagellum, which has no counterpart in more complex cells. In 1973 it was discovered that some bacteria swim by rotating their flagella. So the bacterial flagellum acts as a rotary propellor -- in contrast to the cilium, which acts more like an oar.
The structure of a flagellum is quite different from that of a cilium. The flagellum is a long, hairlike filament embedded in the cell membrane. The external filament consists of a single type of protein, called "flagellin." The flagellin filament is the paddle surface that contacts the the liquid during swimming. At the end of the flagellin filament near the surface of the cell, there is a bulge in the thickness of the flagellum. It is here that the filament attaches to the rotor drive. The attachment material is comprised of something called "hook protein." The filament of a bacterial flagellum, unlike a cilium, contains no motor protein; if it is broken off, the filament just floats stiffly in the water. Therefore the motor that rotates the filament-propellor must be located somewhere else. Experiments have demonstrated that it is located at the base of the flagellum, where electron microscopy shows several ring structures occur.
http://www.arn.org/docs/mm/fdsmall.gif
by way of disclaimer some of this info has been used by the nut jobs on the far right to argue intelligent design and although the simple science is pertinent to this discussion I consider its relevance to any arguments concerning space men or gods to be somewhat less than tenable
my two cents
B
ancient kayaker
03-15-2009, 06:51 PM
The flagellum would seem a good example to suport an argument against intelligent design! Thanks for the explanation, I hadn't realized it actually rotates.
Of course, the flagellum concept doesn't actually need a fully rotating bearing, the same motion can be generated by a whip with a 90 deg elbow, which is how I assumed they worked.
Since we're looking for alternative propulsion methods, here's one I don't remember seeing before. It works like the arm motion in the breast stroke, although it is just a variant on the oar principle. I'm not sure how the mechanical aspects could be handled but it is not an insuperable problem.
Of course, the flagellum concept doesn't actually need a fully rotating bearing, the same motion can be generated by a whip with a 90 deg elbow, which is how I assumed they worked.
Since we're looking for alternative propulsion methods, here's one I don't remember seeing before. It works like the arm motion in the breast stroke, although it is just a variant on the oar principle. I'm not sure how the mechanical aspects could be handled but it is not an insuperable problem.
Boston
03-15-2009, 10:52 PM
not only does it rotate but if you look at how its constructed its only a mater of time before they find a way to "discover" its a bio-electric motor
all they need do is map the chemical interaction and it should come clear
problem is most of that kind of thing is cutting edge and only done on nerve cells with this oddball type of microscope that uses wave cancellation
cant remember what its called
all they need do is map the chemical interaction and it should come clear
problem is most of that kind of thing is cutting edge and only done on nerve cells with this oddball type of microscope that uses wave cancellation
cant remember what its called
ancient kayaker
03-15-2009, 11:05 PM
Some exotic variant of the Electron Microscope I assume?
Boston
03-15-2009, 11:09 PM
actually no it is able to observe live samples as aposed to the prepared and thoroughly dead kind that a scanning microscope like the electron does
basically it takes a laser beam splits it
sends one through the sample
reverses the frequency of the other
recombines the beams
canceling out the similar properties
and what is left is then analyzed and collated into a data stream
the result is a live 3d moving image of objects in the 5 to sa 15 nanometer range
I probably shouldn't be discussing it as its still in the experimental phases but I dont think the microscope police are listening
at the moment I think its only being used to study the chemical interaction of neural dendrils in mice
basically it takes a laser beam splits it
sends one through the sample
reverses the frequency of the other
recombines the beams
canceling out the similar properties
and what is left is then analyzed and collated into a data stream
the result is a live 3d moving image of objects in the 5 to sa 15 nanometer range
I probably shouldn't be discussing it as its still in the experimental phases but I dont think the microscope police are listening
at the moment I think its only being used to study the chemical interaction of neural dendrils in mice
sigurd
03-16-2009, 08:02 AM
AK - that is strange. I thought at first it was flapping, like the mirage hobie kajak drive, but from the description it sounds like the lower illustration is from the top, and both arms are counter rotating.
ancient kayaker
03-16-2009, 03:55 PM
Sigurd: that's correct.
Boston: sounds like it's related to holography.
Boston: sounds like it's related to holography.
Boston
03-16-2009, 04:10 PM
no its kinda its own animal
I had lunch up in Boulder the other day with the inventor
or one of em
there fighting over it
so its kinda all on hold and has been for a few years
I had lunch up in Boulder the other day with the inventor
or one of em
there fighting over it
so its kinda all on hold and has been for a few years
Guillermo
11-12-2009, 12:38 PM
Gymnobot:
http://www.bath.ac.uk/news/2009/09/21/robot-fish/
http://images.google.com/images?q=gymnobot&rls=com.microsoft:es-us:IE-SearchBox&oe=UTF-8&sourceid=ie7&rlz=1I7GGLD_en&um=1&ie=UTF-8&ei=ykf8SqOkGo6x4QbewLjMAw&sa=X&oi=image_result_group&ct=title&resnum=4&ved=0CCQQsAQwAw
Cheers.
http://www.bath.ac.uk/news/2009/09/21/robot-fish/
http://images.google.com/images?q=gymnobot&rls=com.microsoft:es-us:IE-SearchBox&oe=UTF-8&sourceid=ie7&rlz=1I7GGLD_en&um=1&ie=UTF-8&ei=ykf8SqOkGo6x4QbewLjMAw&sa=X&oi=image_result_group&ct=title&resnum=4&ved=0CCQQsAQwAw
Cheers.
fastfreddy
11-12-2009, 10:49 PM
Guys, any ideas on alternative (say fish-like) propulsion for a small personal submarine?
Check out the original "Batman Movie". The Penguin had a sub with fins for propulsion.
Check out the original "Batman Movie". The Penguin had a sub with fins for propulsion.
View Full Version : Fish-like propulsion
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