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Instead of a single cable, build a tube elevator shaft, for safety.
http://www.abcparislive.com/eiffel_towe … ms.htm]The bottom could be a structure like the Eifel Tower, but composed of nanotube epoxy resin baloons. It would self support, reducing the stress on the upper part.
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Yep, and if was shaped like an upside down "U" tube manometer it could used as fuel line to space.
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No, no it wouldn't.
The space elevator cable is not standing up from the ground, its hanging from the counterweight in space. Building a huge tower, particularly one prone to terminal failure (balloons?), would be pretty useless especially considering how little of the length would have any support bennefit.
The tube idea is still just stupid, because of the huge numbers of pumps needed to make it operate, and the syphon will never prime because of the massive force of gravity pulling down gasses equally. You could get far, far higher rates by simply pulling up a tank from the ground.
[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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The tube idea is still just stupid, because of the huge numbers of pumps needed to make it operate, and the syphon will never prime because of the massive force of gravity pulling down gasses equally. You could get far, far higher rates by simply pulling up a tank from the ground.
Since both ends are at the same level or one end 500 feet higher than the other a flow will naturally occur from one to the other of the upside U tube manometer. No plumbing trick just a law of physics.
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Actually it is a plumbing trick, a trick that ignores the problem of the universality of escape velocity. There is no possible way to move a gas in a useful quantity up into geostationary orbit simply by creating a vacuum above it, as a syphon does. Gravity will pull the gas back down in the "up" side of the tube before it ever gets anywhere near the top, and even if all the gas falls down the "out" end, the vacuum it creates is not enough to pull more gas up.
The proof of this is simple: Earth has an atmosphere. If Earth's escape velocity were not much higher then the natural speed of gasses, then all our air would just blow away.
[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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Actually, it is as small difference of pressure and no vacuum is felt inside the tube since the inside of the tube is never exposed to space for the full lenghth of the tube. This means any change of pressure no matter how small on one side of the tube will create a difference of pressure between the two ends and a flow will occur within the tube. Energy is conserved within the tube fore the entire length of the tube no matter how long it is. Bernoulli figured this out long ago.Bernoulli was not a trickster.
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Actually, it is as small difference of pressure and no vacuum is felt inside the tube since the inside of the tube is never exposed to space for the full lenghth of the tube. This means any change of pressure no matter how small on one side of the tube will create a difference of pressure between the two ends and a flow will occur within the tube. Energy is conserved within the tube fore the entire length of the tube no matter how long it is. Bernoulli figured this out long ago.Bernoulli was not a trickster.
Effectively creating a vacuum is creating a pressure change. For the gas to flow up the pressure change per length must be less then the change in potential energy per length. You say the pressure change wants the gas to flow up but gravity wants the gas to flow down. The greater force will win.
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Yes look at a smoke stack air flows in the bottom and out the top with no heat being applied. There would only be an elevation change of about 1000 feet between the two open ends equal to about what the flow of a 1000 foot smoke stack would create. Except, in this case the smoke stack is very long so frictional loss would happen. However, there should be a net flow for a given cross section.You could also help it along with a pump on either side although it would not be needed. In effect it is a very long siphon.
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Errorist, I don't know why I even bother to talk to you anymore, since you are either not listening or not bothering to even try and understand what I'm saying.
I have told you time and time again, on three different threads, over multiple pages of writing, exactly and fundimentally why you simply cannot move gasses up such a pipeline soley by their natural kenetic energy. You cannot.
It doesn't matter what arrangement of plumbing and pipes and such you come up with, none of that matters, not one single bit. The problem cannot be snuck around with clever trickery: I know this beyond doubt because it is against the laws of physics for any such scheme to work. Any scheme. Any idea. Any trick... None of them can get around the problems.
I will restate once again why the syphon idea will not work, and it is the same reason why your original single-pipe plan would not work, not that you botherd to understand me then.
1: Escape velocity applies to all things, including the molecules of a gas, and you must get pretty close to this velocity to reach geostationary orbit straight up. If the molecules of the gas do not move at this speed, then they will never, ever reach the top.
2: The syphon does not make gas molecules move any faster. What a syphon does is create a weak vacuum at the top of the "up" end, that is, a region where there are fewer gas molecules. Since gasses will try and fill all volumes with equal density, on small scales molecules from the bottom of the "up" end will then move up the pipe to enter this region.
3: Gasses are compressable. You can easily squeeze a balloon or a plunger because gasses are mostly empty space, so it is no problem for the molecules to pack more tightly in a reduced volume, to a point.
These things taken together tell us why the syphon idea will not work, it is the same reason your single-pipe pipeline won't work by just admitting gasses in, and is the same reason why the Earth can retain its atmosphere:
So, you prime the syphon with a load of bottled gas winched up the line or with a pump, and you create the low/no pressure void at the top, and open the injection valve on the "up" side... Gasses are then admitted into the bottom, and through their natural kenetic motion will begin to rush up the pipeline to move into the low/no pressure void.
But then it stops
It just plain stops
The gas will simply stop before it gets very far up the pipe, maybe a few kilometers, and it will simply stop. Why? The gas molecules are moving, and moving pretty fast (~1-2km/sec for H2) just from the natural kenetic motion, but it isn't fast enough. So, even the fastest molecules flinging straight up the pipe only get up a few kilometers, and fall back down again, just like a baseball thrown into the air.
So what do you do? Pump more gas into the bottom? This will do you no good, no good at all, because the gas will compress: simply increasing pressure will NOT increase the speed of the molecules, only increases in temperature increases speed. So, you have more molecules flinging straight up, but none of them are going any faster then at lower pressures, so still none of them will reach the top.
So you want to increase temperature in order to crank up the speed of the molecules? Go right ahead... your pipeline will burn and melt and the gas molecules will break down before you ever get to those speeds.
[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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So what do you do? Pump more gas into the bottom? This will do you no good, no good at all, because the gas will compress:
If you double the pressure you will double the high the gas can go to. Air will go up about 7km at one atmosphere with a 63% drop in pressure at the top. If you use 2 atmospheres of pressure you will reach an altitude of 14Km. If you compress the gas to a point where it is no longer an ideal gas (seen generalized compressibility (z)) you will get even higher. Of course with just one pump you pipe will break before you ever get the column of gas high enough. Or maybe it wouldn't with hydrogen. I think that at about 80 atmospheres you might just make it with hydrogen. I am not sure I haven’t done the math that way. Can a pipe withstand 80 atmospheres at 20 degrees Celsius? Maybe?
This may partly explain why Venus has little hydrogen. The pressure on Venus is 90 atmospheres and it has less gravity.
Temperature on the other hand would be a bad way to try and raise the gas. The heigh at which the pressure drops by 63% is given by P*g/rho. The effect of raising the temperature is to decrease the density. But do half the density we would have to double the temperature in Kelvin. That would mean raising the temperature by over 273 degrees Celsius just to double the height the gas will reach. The pipe will definitely melt. It think diamond can withstand a thousand degrees but it weighs much more then CNT.
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I still think it will work without a pump. Because the top of the upside down "U" tube has the average pressure of the top opening of it that is 1000 feet above sea level and the other end which is at sea level. So the tube will have and average pressure difference between the two openings that are at two different elevations. This is what will create the flow. The pressure difference at altitude at each opening is what creates the flow and it is enough to over come the gravity. Otherwise, Bernoulli was wrong. If it works for the smoke stack where gravity is greater the closer you get to the Earth then it stands for reasoning that it will work the further away you get from Earth because gravity looses its hold and is less the further you are away from Earth.
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I still think it will work without a pump. Because the top of the upside down "U" tube has the average pressure of the top opening of it that is 1000 feet above sea level and the other end which is at sea level. So the tube will have and average pressure difference between the two openings that are at two different elevations. This is what will create the flow. The pressure difference at altitude at each opening is what creates the flow and it is enough to over come the gravity. Otherwise, Bernoulli was wrong. If it works for the smoke stack where gravity is greater the closer you get to the Earth then it stands for reasoning that it will work the further away you get from Earth because gravity looses its hold and is less the further you are away from Earth.
Without pumps the pressure difference in the tube will never exceed one atmosphere you will need about 80 atmospheres of pressure to pump hydrogen into space and about 1000 atmospheres to pump air into space.
Actually Go ahead and use Bernoulli’s law and see what you get. You won’t reach space. Just to get you started on earth start with one atmosphere and zero velocity, in space you have zero atmospheres and zero velocity. No hypersonic flows because you will have too many friction losses for any reasonably sized pipe.
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Remember the the U is totally closed and never sees the vacuum of space except both ends which are near sea level.
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Remember the the U is totally closed and never sees the vacuum of space except both ends which are near sea level.
And it will not see over 80 atmoshperes of preassure at either end.
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80 bars = 1160.302 Psi
That is not much pressure to get it up there. Our powerplants have hydrogen bottles that have 2300psi in them.
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Opps I mean 80 Atmosheres. Oh wait they are the same as I orginally thought. Opps again.
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Also, 1000 bars is not that much pressure.
1000 bars = 14503.77 psi
There are hydraulic pumps that can pump to 100,000psi.
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Also, 1000 bars is not that much pressure.
1000 bars = 14503.77 psi
There are hydraulic pumps that can pump to 100,000psi.
Well I havn't done all the math but how think would the walls have to be of a CNT pipe to support 1000 bars of preassure?
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There are hydraulic pumps that can pump to 100,000psi.
With what kind of flow rate and how much power do they consume. Do you have a link? Do they work for gasses or cryogenic liquids?
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Opps I mean 80 Atmosheres.
Ok so an atmosphere is about what at sea level 30 inches if a hurricane isn't coming.
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Ok so an atmosphere is about what at sea level 30 inches if a hurricane isn't coming.
Yes
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With what kind of flow rate and how much power do they consume. Do you have a link? Do they work for gasses or cryogenic liquids?
I am pretty sure GE uses them for hydraulic pumps in order to make dimonds under extreme pressures.
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I am pretty sure GE uses them for hydraulic pumps in order to make dimonds under extreme pressures.
It doesn't sound like that kind of preassure will be kind to CNT. Infact you may turn part of the pipe into diamonds that way.
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Here is one that can deliver 2800 bars.
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You know what if you could provide enough pressure the column of gas would be self supporting. The nano tubes would not have to lift the weight of the gas they would only have to lift the weight of the nano tubes and support the pressure. Recognize though that those pumps are for water not gas.
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