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I was doing some wiring on my boat today for the trolling motor and the conduit was of the plastic flexable type. It was lined with hundreds of circular ribs so it would be flexable.It was about 1/2 inch diameter. I blew into it and it made the strangest whisle. Where these vibrations shock waves? It reminded me of the nano tube and I was wondering if such a design would allow gasses to flow better in the nano tube?
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I don't think you truly understand the meaning of the word "nano" in nano tubes. Things on the nano scale are small, REALY small. Realy, realy, realy small. And at such extreaml small scales, things work really diffrently. The physical forces and concpets that dominate in our macro scale universe such as gravity are irrelevent when applied to the nano-scale. Other forces such as ion attraction, hydrogen bonds, dipole-dipole interactions, and van der Waalss forces, are much more relevent. Most of our physical measures such as distance, velocity, momentum, pressure, and even position are useless in this enviroment, replaced with temperature and concentration. Also things happen on a MUCH more rapid pace then they do in our macro universe. Chemical bonds are formed and broken faster than you could possibly precive it happening. And everything is in constant random (brownian) motion in all directions at speeds that if they were scaled up to the macro would be more like those of spaceships then man.
To put it simply, things don't work on the nano-scale like the do in the macro-scale. Diffrent sets of physical forces predominate and a entirely diffrent set of conditions exists than does on our level.
He who refuses to do arithmetic is doomed to talk nonsense.
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You'd have a hard enough time getting the gasses to FIT in the nanotube at all, much less form a shock front.
Austin is right... when you think about nanotubes, forget all the macroscale laws you are used to using... they don't apply.
[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]
[i]The glass is at 50% of capacity[/i]
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Austin Stanley, GCNRevenger, I agree with you. Think of the nano tube the size and in the shape of that conduit I was talking about though. Imagine the nano tube material made in the size and shape of the conduit.
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If you are repeating your question, then you obviously DON'T understand. The condinute makeing a strange noise due to it's shape is a macro-scale thing, and has no bearing on the movement of molecules through a nanoscale pipe. Sound does not exist on this scale. Indeed, it isn't even usefull to think of the molecules as being in any particular state, gas, liquid, solid whatever. The relevant laws (such as the gass law, fluid dynamics) do not apply on these scales, as the intermolecular forces completely overwhelm them. The reality of this scale is a group of realtivly small molecules moving surounded by a group of bonded, but still constantly moving/flexing carbon atoms.
He who refuses to do arithmetic is doomed to talk nonsense.
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To put things simply Errorist, the microscale world is entirely and completly different from our macroscale one. It might as well be another dimension, since all our "big" world Newtonian physics just isn't true in the realm of the small. All our concepts of matter in our world... none of that works when things get small anymore. You can't even think about matter in the same way. Even the convienant billiard-ball concept of matter is a fairy tale to large degree.
[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]
[i]The glass is at 50% of capacity[/i]
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ftlwright,
I am talking about building a (MACRO WORLD) pipline to space of about 1/4 inch inside diameter with the (MICRO WORLD) nano tube material.I want the gas to flow within the 1/4 inch(MACRO WORLD) opening.This is why I made the analogy with the conduit.
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Sound does not exist on this scale. Indeed, it isn't even usefull to think of the molecules as being in any particular state, gas, liquid, solid whatever. The relevant laws (such as the gass law, fluid dynamics) do not apply on these scales, as the intermolecular forces completely overwhelm them. The reality of this scale is a group of realtivly small molecules moving surounded by a group of bonded, but still constantly moving/flexing carbon atoms.
I knew that at such a tiny scale certain laws no longer applied, but I had not considered that sound would not exist on that scale. Is this known for certain, or is it one of the current theories.
Graeme
There was a young lady named Bright.
Whose speed was far faster than light;
She set out one day
in a relative way
And returned on the previous night.
--Arthur Buller--
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To me it sounds realistic because some of the molecules may not even fit into the nano tubes, so if none are there then how can you generate a wave pattern?
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Sound does not exist on this scale. Indeed, it isn't even usefull to think of the molecules as being in any particular state, gas, liquid, solid whatever. The relevant laws (such as the gass law, fluid dynamics) do not apply on these scales, as the intermolecular forces completely overwhelm them. The reality of this scale is a group of realtivly small molecules moving surounded by a group of bonded, but still constantly moving/flexing carbon atoms.
I knew that at such a tiny scale certain laws no longer applied, but I had not considered that sound would not exist on that scale. Is this known for certain, or is it one of the current theories.
Graeme
Yes, thats because sound waves are the orderd vibration of molecules/atoms, and down on this scale the particles are so big compared to the volume considerd that there isn't enough room for there for there to be such ordering.
[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]
[i]The glass is at 50% of capacity[/i]
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ftlwright,
I am talking about building a (MACRO WORLD) pipline to space of about 1/4 inch inside diameter with the (MICRO WORLD) nano tube material.I want the gas to flow within the 1/4 inch(MACRO WORLD) opening.This is why I made the analogy with the conduit.
If you build a whistle out of nanotubes on a macro scale then it may work. The key is to get an air cavity to resonate some how. However, what the while is made out of help transfer the sound energy from the resonating cavity to the air around it and I don’t know if nanotubes will do that effectively. They are not shock waves though because for them to be shock waves you would have to be able to blow faster then the speed of sound. I think the big difference between shock waves and sound waves is shock waves have enough momentum to cause a bulk flow of the material well sound waves may push the air ahead of it during compression but will get pushed back during decompression. I may misunderstand shock waves though because I only took one fluid mechanics course and it did not deal with shock waves.
Dig into the [url=http://child-civilization.blogspot.com/2006/12/political-grab-bag.html]political grab bag[/url] at [url=http://child-civilization.blogspot.com/]Child Civilization[/url]
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It was strange using that conduit for the experiment.I was wondering if the rings were causing this whistle sound and would the turbulance in those ring cavities prevent errosion from occuring if little eddies are created thus allowing most of the air mass to just slip on by without contacting the sides of the tube?
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It was strange using that conduit for the experiment.I was wondering if the rings were causing this whistle sound and would the turbulance in those ring cavities prevent errosion from occuring if little eddies are created thus allowing most of the air mass to just slip on by without contacting the sides of the tube?
Generally it assumed when fluid flows that the velocity of the fluid on the edges of the container is zero. Thus fluid always slips by the walls of the container. However even though the fluid is not moving or moving slowly at the edges of the pipe it still exerts a shear force on the pipe. If the shear force on the pipe is greater then the shear strength of the pipe then pieces of it could be pealed off. Now the pipe is not perfectly smooth but ruff and the loads on some sections of the pipe will be greater then others. The places where the stresses are the greatest will break first.
Fluid will not flow unless a shear force is applied to it. In Newtonian flow the shear forces is uniform though the fluid. In non Newtonian flow the flow is greater is some sections of the fluid then others. Eddies are the result of the fluid flow creating low pressure regions that must be filled in. The circulation direction is governed by the surrounding forces including the shear from the surrounding fluid and the psudeo force caused by the rotation of the earth.
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If you are repeating your question, then you obviously DON'T understand.
What's wrong with that?
I also wonder about that macro-scale tubing. There used to be a popular child's toy that did the same thing. Why does it yield that pitch, which is a function of the flow velocity rather than a harmonic of the tube length?
What's making that sound? It's a perfectly legitimate - and potentially useful - question.
Regarding sound on the microscopic scale:
Sound does not exist on this scale. Indeed, it isn't even usefull to think of the molecules as being in any particular state, gas, liquid, solid whatever. The relevant laws (such as the gass law, fluid dynamics) do not apply on these scales, as the intermolecular forces completely overwhelm them. The reality of this scale is a group of realtivly small molecules moving surounded by a group of bonded, but still constantly moving/flexing carbon atoms.
Four statements, none of which are necessarily wrong, but none of which necessarily support each other, either. The dots must be connected for this to be a useful argument.
Macro-scale descriptions won't even work on the macro-scale if the assumptions you use don't match the system you're describing. Pre-supposing sound doesn't exist in any model of nanoscale phenomena can tempt one to neglect acoustic potential energy. Assuming there is no ordering to the motion of molecules in any system at that scale can tempt one to neglect mass transport phenomena and a host of other effects. Yet these effects can not only readily exist at the nanoscale but can "swamp" the net effects of other intermolecular interactions. You can set up a system that won't have them, but not by ignoring them.
Errorist might even find them in his corrugated tubing.
"We go big, or we don't go." - GCNRevenger
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It was a high pitched sound and ear piercing if you twisted the end of the conduit towards your ear. It worked with ten foot piece as well as the two foot piece that was left over. In either case you had to blow moderately and not to hard and so it seemed it had to reach a predetermined velocity for it to work.
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I'm sorry if I misunderstood what you proposed. It was my understanding that you were thinking about shaping an individual strand in such a fashion. Please forgive me for being a little short tempered, some of your earlier inqueries have reduced my patience.
CM Edwards, in my statment I was refering specific to examining the phenomenon of molecules moving within a carbonnano tube. For such a stituation all of what I said is certianly true. But in a more general sense my comments are motivated by a general misunderstand of what the nano-scale relm realy is and what it entails. Alot of people have got this weird concept in there head (propigated by Eric Drexler, Ralph Merkle and others) that you can slap molecules around and build gears and what not on a nano-scale just like you could on a macro-scale. But this is foolishness, the chaotic nature of the realm makes such machines impossible.
Nanotechnology IS real, I am probably going to focus my career in chemistry around it in some fashion. But it is not normal physics just scaled down, it is something else entirely. Real nanotechnology is pretty much indistinguishable from normal chemistry except that it's products are chemicals usefull on the nanoscale. It is not "grey goo" or "miracle utility foam" that SF loves to talk about.
He who refuses to do arithmetic is doomed to talk nonsense.
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Austin Stanley,
"I'm sorry if I misunderstood what you proposed."
I'm sorry if I didn't convey my message in the right way also.
I tend to do that from time to time.It is fustrating and sometimes funny and other times quite sad. Don't worry I still like ya!!!
Nano technology is fascinating and the concepts are being put to good use in the medical field these days. Imagine these microdevises in your blood stream constantly scrubbing away plaque from your arteries and preventing heart attacks.
Anyways, I just thought it was a neat experiment and was wondering how it would apply with the large scale nano tube.
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It was a high pitched sound and ear piercing if you twisted the end of the conduit towards your ear. It worked with ten foot piece as well as the two foot piece that was left over. In either case you had to blow moderately and not to hard and so it seemed it had to reach a predetermined velocity for it to work.
This will sound odd, but have you tried swinging the lengths of tubing around overhead like a sling? This will give you a relatively simple means of controlling the flow rate through and around each tube.
I don't recall the name of the children's toy, but I do recall that it operated in roughly that fashion and had a fairly wide range of pitch.
PS: Before I ran across this post, I had completely forgotten about this simple, tunable sound transducer. I was looking for something like this recently. Thanks.
"We go big, or we don't go." - GCNRevenger
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No it didn't but what you just described reminds me of the pipeline from the Artic Ocean to the Equator. Rotational velocity combined with angular velocity.
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No it didn't but what you just described reminds me of the pipeline from the Artic Ocean to the Equator. Rotational velocity combined with angular velocity.
Please be careful with terminology, the pipeline you proposed in http://www.newmars.com/forums/viewtopic.php?t=2495]This Thread is just your theoretical one, not one that exists.
Graeme
There was a young lady named Bright.
Whose speed was far faster than light;
She set out one day
in a relative way
And returned on the previous night.
--Arthur Buller--
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