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Ion drive for aircraft imminent.
The nanotubes may become longer lasting by using bundles of nanotubes:
Arrays of Bundles of Carbon Nanotubes as Field Emitters. NASA’s Jet Propulsion Laboratory, Pasadena, California Thursday, 01 February 2007 Area-averaged current densities exceed those of arrays of single nanotubes. "Experiments have shown that with suitable choices of critical dimensions, planar arrays of bundles of carbon nanotubes (see figure) can serve as high-current-density field emitter (cold-cathode) electron sources. Whereas some hot-cathode electron sources must be operated at supply potentials of thousands of volts, these cold-cathode sources generate comparable current densities when operated at tens of volts. Consequently, arrays of bundles of carbon nanotubes might prove useful as cold-cathode sources in miniature, lightweight electron-beam devices (e.g., nanoklystrons) soon to be developed." http://www.techbriefs.com/component/...-sciences/1206 And in any case you don't need to use the nanowires as electron emitters to get the ionization effect. You get it as well from the intense electric fields generated by wires at the nanoscale in accordance with Peek's Law: https://en.wikipedia.org/wiki/Peek%27s_law Note it may be the nanoscale wires might not even need to be carbon nanotubes. According to Peek's Law simply being at nanoscale diameters is sufficient to generate the intense fields. Since there is much research ongoing with metallic nanowires they as well could be used to confirm the better efficiency of ionic propulsion with wires at the nanoscale. In regards to getting longer nanotubes by tying them together, that has already been confirmed experimentally by a team at Rice University, the leading center for nanotechnology in the U.S. That research was published in Nature Materials, the associated journal in materials science to Nature, the leading science journal in the world. The Rice team was able to show simply tying nanotubes together produced longer nanotubes of greater current capacity than the copper or aluminum wires now in use and at lighter weight. About the power requirements, the ionic propulsion with ionizing wires, called corona wires, at the nanoscale has improved power-to-thrust ratio. Then the needed power can be supplied by onboard batteries. Bob Clark ---------------------------------------------------------------------------------------------------------------------------------- Finally, nanotechnology can now fulfill its potential to revolutionize 21st-century technology, from the space elevator, to private, orbital launchers, to 'flying cars'. This crowdfunding campaign is to prove it: Nanotech: from air to space. https://www.indiegogo.com/projects/n...ce/x/13319568/ ---------------------------------------------------------------------------------------------------------------------------------- "John Larkin" wrote in message ... On Tue, 1 Nov 2016 11:09:13 -0400, "Robert Clark" wrote: Nanotechnology makes possible an "ion drive" for air vehicles analogous to the famous ion drive of NASA's deep space probes: Carbon nanotubes for "Ionic Wind" Craft or "Ionocraft". Clark R* Department of Mathematics, Widener University, USA Review Article Volume 1 Issue 2 / Received Date: September 26, 2016 / Published Date: October 20, 2016 Abstract Peter Thiel of the Founders Fund once famously said, "We wanted flying cars, and we got 140 characters."But nanotechnology now does make possible the long desired flying cars. It's a different propulsion method though than propellers or jets however. It's propulsion by electric fields known as electrohydrodynamic propulsion (EHD). It works by ionizing air then using electric fields to propel the charged air molecules rearward, thus producing thrust. It's quite analogous to the famous space ion drive of NASA. EHD has been known at least since the sixties. Its problem is, as with ion drive, the thrust is so low. So far the EHD craft have not been able to lift both themselves and their power supplies. The ones made so far leave the power supply on the ground and connect to the craft through power cables. But the equations of EHD suggest the thrust for the power required gets larger for thinner ionizing wires. In fact if the wires are at the nanoscale then this important thrust-to-power ratio can be a hundred times higher than for the craft constructed so far. This would be enough to lift the craft and the power supply. This research is to prove what the mathematics suggests. Note that if it works then all propeller and rotor driven craft become obsolete. Also, intermediate range automobile travel would be taken over by the EHD craft, so a large proportion of carbon-emissions would be eliminated, replaced by this zero-emission travel method. In regards to space propulsion, since EHD is so similar to ion drive, using components at the nanoscale may also work to improve the thrust of ion drive. This would be important to shortening the flight times of spacecraft using such drives. This is important not just for robotic spacecraft but also satellites that use such ion drives to reach their final GEO destinations. As it is now, the ion drives used have such low thrust it takes months for such satellites to reach GEO, resulting in millions of dollars of lost revenue to the satellite companies. Being able to increase the thrust of these drives would reduce the flight time, and therefore reduce this lost revenue. Keywords: Electrohydrodynamic propulsion; Carbon nanotubes; Nanowires; Ionic wind; Ionocraft; Plasma drive https://medwinpublishers.com/NNOA/vo...=23&issueId=63 Bob Clark Post again when Chevy dealerships are selling flying cars. Carbon nanotubes are the idiotic craze of the day, and are pretty much useless so far. As electron or ion emitters, they quickly destroy themselves. And they still don't violate conservation of energy. Where is all the zero-pollution power going to come from? ---------------------------------------------------------------------------------------------------------------------------------- Finally, nanotechnology can now fulfill its potential to revolutionize 21st-century technology, from the space elevator, to private, orbital launchers, to 'flying cars'. This crowdfunding campaign is to prove it: Nanotech: from air to space. https://www.indiegogo.com/projects/n...ce/x/13319568/ ---------------------------------------------------------------------------------------------------------------------------------- That's hilarious, tying tiny nanotubes together with fancy knots. The nanotech bubble popped roughly 10 years ago. I was involved with academics and inventors and slimy VCs all hoping to cash in on the upside of the Next Big Thing. -- John Larkin Highland Technology, Inc lunatic fringe electronics --- |
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Ion drive for aircraft imminent.
Good question. You can make one of these EHD devices yourself, commonly
called "lifters", to test this. Do a web search on: "lifters" and "power supply" for the many explanations online for how to make them. My guess is since it's the intense electric fields that is creating the ionization they will still work in high humidity or rain. Note also the EHD effect also works with liquids. Bob Clark ---------------------------------------------------------------------------------------------------------------------------------- Finally, nanotechnology can now fulfill its potential to revolutionize 21st-century technology, from the space elevator, to private, orbital launchers, to 'flying cars'. This crowdfunding campaign is to prove it: Nanotech: from air to space. https://www.indiegogo.com/projects/n...ce/x/13319568/ ---------------------------------------------------------------------------------------------------------------------------------- wrote in message ... On Tuesday, November 1, 2016 at 8:09:00 AM UTC-7, Robert Clark wrote: Nanotechnology makes possible an "ion drive" for air vehicles analogous to the famous ion drive of NASA's deep space probes: Carbon nanotubes for "Ionic Wind" Craft or "Ionocraft". Clark R* Department of Mathematics, Widener University, USA Review Article Volume 1 Issue 2 / Received Date: September 26, 2016 / Published Date: October 20, 2016 Abstract Peter Thiel of the Founders Fund once famously said, "We wanted flying cars, and we got 140 characters."But nanotechnology now does make possible the long desired flying cars. It's a different propulsion method though than propellers or jets however. It's propulsion by electric fields known as electrohydrodynamic propulsion (EHD). It works by ionizing air then using electric fields to propel the charged air molecules rearward, thus producing thrust. It's quite analogous to the famous space ion drive of NASA. EHD has been known at least since the sixties. Its problem is, as with ion drive, the thrust is so low. So far the EHD craft have not been able to lift both themselves and their power supplies. The ones made so far leave the power supply on the ground and connect to the craft through power cables. But the equations of EHD suggest the thrust for the power required gets larger for thinner ionizing wires. In fact if the wires are at the nanoscale then this important thrust-to-power ratio can be a hundred times higher than for the craft constructed so far. This would be enough to lift the craft and the power supply. This research is to prove what the mathematics suggests. Note that if it works then all propeller and rotor driven craft become obsolete. Also, intermediate range automobile travel would be taken over by the EHD craft, so a large proportion of carbon-emissions would be eliminated, replaced by this zero-emission travel method. In regards to space propulsion, since EHD is so similar to ion drive, using components at the nanoscale may also work to improve the thrust of ion drive. This would be important to shortening the flight times of spacecraft using such drives. This is important not just for robotic spacecraft but also satellites that use such ion drives to reach their final GEO destinations. As it is now, the ion drives used have such low thrust it takes months for such satellites to reach GEO, resulting in millions of dollars of lost revenue to the satellite companies. Being able to increase the thrust of these drives would reduce the flight time, and therefore reduce this lost revenue. Keywords: Electrohydrodynamic propulsion; Carbon nanotubes; Nanowires; Ionic wind; Ionocraft; Plasma drive https://medwinpublishers.com/NNOA/vo...=23&issueId=63 Bob Clark Do they work when it's raining / in humid environments? Michael --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus |
#24
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Ion drive for aircraft imminent.
The commonly used name for these EHD devices made by amateurs is "lifters".
The problem with their not being able to fly independently is the power supplies are so heavy. Look for example at the lifter he How to: "Lifter" Power Supply. https://www.youtube.com/watch?v=tfdsEVjBpBU Quite commonly the lifters weigh, and the thrust they can produce, is in the range of grams but the power supplies weigh in the range of kilograms. So how do you solve that problem? Let me give an analogy. Many people are aware of the technical innovations the Wright brothers made to be able to develop a successful flying machine. They made their own wind tunnel. They tested various air foils to find efficient ones of high lift. They developed a warping wing technique for steering. However, not as well known is the one key innovation they made for which all those other innovations would have been worthless. When many scientists of the time after doing a mathematical analysis asserted that no heavier-than air flying machine could work, oddly enough they were *right*. But the problem was, they were basing this on the power sources widely known at the time, steam engines. But the steam engines were so inefficient they could not supply sufficient power for their weight. They were too heavy. Around the time of the Wright brothers though the internal combustion gasoline engine was coming into use for automobiles, but they were still too heavy for the Wright brothers use. So the one *key* innovation the Wright brothers made was that they designed and built their OWN lightweight internal combustion engine. Now, back to the EHD propulsion method. The power supplies are too heavy, so what can we do about that? Well, you can make them out of lightweight materials. That's a possible route to follow, but most amateur and even professional experimenters have used ready made power supplies or used ready made parts to build them. The result is they are all pretty standard weight for the power they put out. But let's analyze this further, *why* are the power supplies so heavy? It turns out the reason they are so heavy is the voltage needed for the ion propulsion method is in the range of tens of thousands of volts, frequently as high as 50,000 volts. This then requires heavy transformers to produce voltage this high. Alright then, can we find a way to reduce the required voltage? Yes! It turns out if you reduce the diameter of the wires doing the ionization of the air then the required voltage is reduced. In fact, according to the math if the wires are at the nanoscale then the required voltage might be reduced to only tens of volts instead of tens of thousands of volts. For the small-scale lifters, if you used now wires at the nanoscale, it may be they could be powered by a couple of 9-volt batteries connected in series. So that's the key point, for nanowires the voltage required for ionization is severely reduced. This is the content of Peek's Law: https://en.wikipedia.org/wiki/Peek%27s_law Bob Clark ---------------------------------------------------------------------------------------------------------------------------------- Finally, nanotechnology can now fulfill its potential to revolutionize 21st-century technology, from the space elevator, to private, orbital launchers, to 'flying cars'. This crowdfunding campaign is to prove it: Nanotech: from air to space. https://www.indiegogo.com/projects/n...ce/x/13319568/ ---------------------------------------------------------------------------------------------------------------------------------- "John Larkin" wrote in message ... On Tue, 1 Nov 2016 10:06:41 -0700 (PDT), wrote: On Tuesday, November 1, 2016 at 8:09:00 AM UTC-7, Robert Clark wrote: Nanotechnology makes possible an "ion drive" for air vehicles analogous to the famous ion drive of NASA's deep space probes: Carbon nanotubes for "Ionic Wind" Craft or "Ionocraft". Clark R* Department of Mathematics, Widener University, USA Review Article Volume 1 Issue 2 / Received Date: September 26, 2016 / Published Date: October 20, 2016 Abstract Peter Thiel of the Founders Fund once famously said, "We wanted flying cars, and we got 140 characters."But nanotechnology now does make possible the long desired flying cars. It's a different propulsion method though than propellers or jets however. It's propulsion by electric fields known as electrohydrodynamic propulsion (EHD). It works by ionizing air then using electric fields to propel the charged air molecules rearward, thus producing thrust. It's quite analogous to the famous space ion drive of NASA. EHD has been known at least since the sixties. Its problem is, as with ion drive, the thrust is so low. So far the EHD craft have not been able to lift both themselves and their power supplies. The ones made so far leave the power supply on the ground and connect to the craft through power cables. But the equations of EHD suggest the thrust for the power required gets larger for thinner ionizing wires. In fact if the wires are at the nanoscale then this important thrust-to-power ratio can be a hundred times higher than for the craft constructed so far. This would be enough to lift the craft and the power supply. This research is to prove what the mathematics suggests. Note that if it works then all propeller and rotor driven craft become obsolete. Also, intermediate range automobile travel would be taken over by the EHD craft, so a large proportion of carbon-emissions would be eliminated, replaced by this zero-emission travel method. In regards to space propulsion, since EHD is so similar to ion drive, using components at the nanoscale may also work to improve the thrust of ion drive. This would be important to shortening the flight times of spacecraft using such drives. This is important not just for robotic spacecraft but also satellites that use such ion drives to reach their final GEO destinations. As it is now, the ion drives used have such low thrust it takes months for such satellites to reach GEO, resulting in millions of dollars of lost revenue to the satellite companies. Being able to increase the thrust of these drives would reduce the flight time, and therefore reduce this lost revenue. Keywords: Electrohydrodynamic propulsion; Carbon nanotubes; Nanowires; Ionic wind; Ionocraft; Plasma drive https://medwinpublishers.com/NNOA/vo...=23&issueId=63 Bob Clark Do they work when it's raining / in humid environments? Michael No. And under even ideal conditions, they don't work for long. Why do people invent (and press release) crazy sci-fi dreams that ignore basic physics? There is a reason why helicopters have gas turbine engines and giant fan blades... and horrendous fuel consumption rates. Why don't they just use their jet engines to lift the vehicle? -- John Larkin Highland Technology, Inc picosecond timing precision measurement jlarkin att highlandtechnology dott com http://www.highlandtechnology.com --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus |
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Ion drive for aircraft imminent.
Yes, that's a good example. Electric, battery-powered airplanes and
helicopters already exist. However, the key point is according to the mathematics you can get even better power-to-thrust ratio with ionic propulsion using ionizing wires at the nanoscale than helicopters achieve. Bob Clark ---------------------------------------------------------------------------------------------------------------------------------- Finally, nanotechnology can now fulfill its potential to revolutionize 21st-century technology, from the space elevator, to private, orbital launchers, to 'flying cars'. This crowdfunding campaign is to prove it: Nanotech: from air to space. https://www.indiegogo.com/projects/n...ce/x/13319568/ ---------------------------------------------------------------------------------------------------------------------------------- wrote in message ... On Tuesday, November 1, 2016 at 10:20:43 AM UTC-7, John Larkin wrote: ... Why do people invent (and press release) crazy sci-fi dreams that ignore basic physics? There is a reason why helicopters have gas turbine engines and giant fan blades... and horrendous fuel consumption rates. Why don't they just use their jet engines to lift the vehicle? -- John Larkin Highland Technology, Inc picosecond timing precision measurement Oh I dunno, I thought this 18-rotor electric copter-thingie was kind of cute. http://newatlas.com/volocopter-manned-flight/42704/ Michael --- |
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Ion drive for aircraft imminent.
As mentioned previously, battery-powered airplanes and helicopters do exist.
The ionic propulsion will likewise be battery-powered but at a more efficient power usage, if the ionizing wires are at the nanoscale. The greater efficiency for ionic propulsion with nanoscale wires can be confirmed with any wires at the nanoscale, not just carbon nanotubes. For example, the intense fields created by nanoscale wires in microcircuitry boards is well-known to those in the field. So anyone who has familiarity working with microcircuitry boards with nanoscale wiring could confirm this. And that's all that's required. That in itself would be the game changer. Even if it's only done on a model the size of a model airplane, once it's shown that nanoscale wiring for ionic propulsion produced better power-to-thrust ratio than helicopters, that would be sufficient for this to supplant helicopters as a hovering transport method. Bob Clark ---------------------------------------------------------------------------------------------------------------------------------- Finally, nanotechnology can now fulfill its potential to revolutionize 21st-century technology, from the space elevator, to private, orbital launchers, to 'flying cars'. This crowdfunding campaign is to prove it: Nanotech: from air to space. https://www.indiegogo.com/projects/n...ce/x/13319568/ ---------------------------------------------------------------------------------------------------------------------------------- "Gutless Umbrella Carrying Sissy" wrote in message ... "Robert Clark" wrote in : Nanotechnology makes possible an "ion drive" for air vehicles analogous to the famous ion drive of NASA's deep space probes: Carbon nanotubes for "Ionic Wind" Craft or "Ionocraft". Clark R* Department of Mathematics, Widener University, USA Review Article Volume 1 Issue 2 / Received Date: September 26, 2016 / Published Date: October 20, 2016 Abstract Peter Thiel of the Founders Fund once famously said, "We wanted flying cars, and we got 140 characters."But nanotechnology now does make possible the long desired flying cars. The reason we don't have flying cars has nothing to do with the method of propulsion. We've *had* flying cars for decades. And this will do nothing to make them a) cheaper, b) easier to fly, or c) safer when there are tens of millions of them in the air at once. Note that if it works then all propeller and rotor driven craft become obsolete. Just like all propeller and rotor drive craft became obsolete when jet engeins were invented. Sure. Also, intermediate range automobile travel would be taken over by the EHD craft, Effectively, jet powered cars? Because it sounds like there will be a high speed exhaust of _some_ kind behind the vehicle. Which makes it . . . unlikely. Plus, two orders of magnitude increase in thrust to weight from current ion engines isn't even close to what a car needs. so a large proportion of carbon-emissions would be eliminated, replaced by this zero-emission travel method. The electricity has to come from _somewhere_. As is usual, nearly universal, with all announcement of revolutionary new technologies, this reads more like a prospectus for investors than anything else. Which is to say, he wants to invest a whole lof of other people's money into finding out if it works. If he really believed it would work, he'd invest his own money, and keep _all_ the profits himself. -- Terry Austin |
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Ion drive for aircraft imminent.
On Thu, 3 Nov 2016 09:16:52 -0400, "Robert Clark"
wrote: The nanotubes may become longer lasting by using bundles of nanotubes: Arrays of Bundles of Carbon Nanotubes as Field Emitters. NASA’s Jet Propulsion Laboratory, Pasadena, California Thursday, 01 February 2007 Area-averaged current densities exceed those of arrays of single nanotubes. "Experiments have shown that with suitable choices of critical dimensions, planar arrays of bundles of carbon nanotubes (see figure) can serve as high-current-density field emitter (cold-cathode) electron sources. Whereas some hot-cathode electron sources must be operated at supply potentials of thousands of volts, these cold-cathode sources generate comparable current densities when operated at tens of volts. Consequently, arrays of bundles of carbon nanotubes might prove useful as cold-cathode sources in miniature, lightweight electron-beam devices (e.g., nanoklystrons) soon to be developed." http://www.techbriefs.com/component/...-sciences/1206 And in any case you don't need to use the nanowires as electron emitters to get the ionization effect. You get it as well from the intense electric fields generated by wires at the nanoscale in accordance with Peek's Law: https://en.wikipedia.org/wiki/Peek%27s_law Note it may be the nanoscale wires might not even need to be carbon nanotubes. According to Peek's Law simply being at nanoscale diameters is sufficient to generate the intense fields. Since there is much research ongoing with metallic nanowires they as well could be used to confirm the better efficiency of ionic propulsion with wires at the nanoscale. In regards to getting longer nanotubes by tying them together, that has already been confirmed experimentally by a team at Rice University, the leading center for nanotechnology in the U.S. That research was published in Nature Materials, the associated journal in materials science to Nature, the leading science journal in the world. The Rice team was able to show simply tying nanotubes together produced longer nanotubes of greater current capacity than the copper or aluminum wires now in use and at lighter weight. About the power requirements, the ionic propulsion with ionizing wires, called corona wires, at the nanoscale has improved power-to-thrust ratio. Then the needed power can be supplied by onboard batteries. Bob Clark Get back to us when Honda is selling flying cars. And note that top-posting is an email thing, discouraged on usenet. -- John Larkin Highland Technology, Inc lunatic fringe electronics |
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Ion drive for aircraft imminent.
On Thu, 3 Nov 2016 09:48:31 -0400, "Robert Clark"
wrote: The commonly used name for these EHD devices made by amateurs is "lifters". The problem with their not being able to fly independently is the power supplies are so heavy. Look for example at the lifter he How to: "Lifter" Power Supply. https://www.youtube.com/watch?v=tfdsEVjBpBU Quite commonly the lifters weigh, and the thrust they can produce, is in the range of grams but the power supplies weigh in the range of kilograms. So how do you solve that problem? Let me give an analogy. Many people are aware of the technical innovations the Wright brothers made to be able to develop a successful flying machine. They made their own wind tunnel. They tested various air foils to find efficient ones of high lift. They developed a warping wing technique for steering. However, not as well known is the one key innovation they made for which all those other innovations would have been worthless. When many scientists of the time after doing a mathematical analysis asserted that no heavier-than air flying machine could work, oddly enough they were *right*. But the problem was, they were basing this on the power sources widely known at the time, steam engines. But the steam engines were so inefficient they could not supply sufficient power for their weight. They were too heavy. Around the time of the Wright brothers though the internal combustion gasoline engine was coming into use for automobiles, but they were still too heavy for the Wright brothers use. So the one *key* innovation the Wright brothers made was that they designed and built their OWN lightweight internal combustion engine. Now, back to the EHD propulsion method. The power supplies are too heavy, so what can we do about that? Well, you can make them out of lightweight materials. That's a possible route to follow, but most amateur and even professional experimenters have used ready made power supplies or used ready made parts to build them. The result is they are all pretty standard weight for the power they put out. But let's analyze this further, *why* are the power supplies so heavy? It turns out the reason they are so heavy is the voltage needed for the ion propulsion method is in the range of tens of thousands of volts, frequently as high as 50,000 volts. This then requires heavy transformers to produce voltage this high. Alright then, can we find a way to reduce the required voltage? High-voltage power supplies don't need heavy transformers. But they do need a source of power. I doubt that an ion thruster could lift its own batteries for five minutes even if the power converter weighs zero. Yes! It turns out if you reduce the diameter of the wires doing the ionization of the air then the required voltage is reduced. In fact, according to the math if the wires are at the nanoscale then the required voltage might be reduced to only tens of volts instead of tens of thousands of volts. For the small-scale lifters, if you used now wires at the nanoscale, it may be they could be powered by a couple of 9-volt batteries connected in series. Again, you won't get enough lift to support those two batteries, and they would be dead in minutes anyhow. The tiny tips would erode rapidly, too. Don't top post on usenet. -- John Larkin Highland Technology, Inc lunatic fringe electronics |
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Ion drive for aircraft imminent.
On 11/3/2016 10:41 AM, John Larkin wrote:
On Thu, 3 Nov 2016 09:48:31 -0400, "Robert Clark" wrote: The commonly used name for these EHD devices made by amateurs is "lifters". The problem with their not being able to fly independently is the power supplies are so heavy. Look for example at the lifter he How to: "Lifter" Power Supply. https://www.youtube.com/watch?v=tfdsEVjBpBU Quite commonly the lifters weigh, and the thrust they can produce, is in the range of grams but the power supplies weigh in the range of kilograms. So how do you solve that problem? Now, back to the EHD propulsion method. The power supplies are too heavy, so what can we do about that? Well, you can make them out of lightweight materials. That's a possible route to follow, but most amateur and even professional experimenters have used ready made power supplies or used ready made parts to build them. The result is they are all pretty standard weight for the power they put out. But let's analyze this further, *why* are the power supplies so heavy? It turns out the reason they are so heavy is the voltage needed for the ion propulsion method is in the range of tens of thousands of volts, frequently as high as 50,000 volts. This then requires heavy transformers to produce voltage this high. Alright then, can we find a way to reduce the required voltage? High-voltage power supplies don't need heavy transformers. But they do need a source of power. I doubt that an ion thruster could lift its own batteries for five minutes even if the power converter weighs zero. Yes! It turns out if you reduce the diameter of the wires doing the ionization of the air then the required voltage is reduced. In fact, according to the math if the wires are at the nanoscale then the required voltage might be reduced to only tens of volts instead of tens of thousands of volts. For the small-scale lifters, if you used now wires at the nanoscale, it may be they could be powered by a couple of 9-volt batteries connected in series. Again, you won't get enough lift to support those two batteries, and they would be dead in minutes anyhow. The tiny tips would erode rapidly, too. Don't top post on usenet. An ion thruster is a form of electric propulsion used for spacecraft propulsion. It creates thrust by accelerating ions with electricity. The term refers strictly to gridded electrostatic ion thrusters, but may more loosely be applied to all electric propulsion systems that accelerate plasma, since plasma consists of ions. wiki (note the last line) Ion thrusters are categorized by how they accelerate the ions, using either electrostatic or electromagnetic force. Electrostatic thrusters use the Coulomb force and accelerate the ions in the direction of the electric field. Electromagnetic thrusters use the Lorentz force. In either case, when an ion passes through an electrostatic grid engine, the potential difference of the electric field converts to the ion's kinetic energy. Ion thrusters have an input power spanning 1–7 kW, exhaust velocity 20–50 km/s, thrust 25–250 millinewtons and efficiency 65–80%.[1][2] The Deep Space 1 spacecraft, powered by an ion thruster, changed velocity by 4300 m/s while consuming less than 74 kilograms of xenon. The Dawn spacecraft broke the record, reaching 10,000 m/s.[1][2] Applications include control of the orientation and position of orbiting satellites (some satellites have dozens of low-power ion thrusters) and use as a main propulsion engine for low-mass robotic space vehicles (for example Deep Space 1 and Dawn).[1][2] The ion thruster is not the most promising type of electrically powered spacecraft propulsion (although the most successful in practice).[2] An ion drive would require two days to accelerate a car to highway speed. The technical characteristics, especially thrust, are considerably inferior to the prototypes described in literature,[1][2] technical capabilities are limited by the space charge created by ions. This limits the thrust density (force per cross-sectional area of the engine).[2] Ion thrusters create small thrust levels (the thrust of Deep Space 1 is approximately equal to the weight of one sheet of paper[2]) compared to conventional chemical rockets, but achieve high specific impulse, or propellant mass efficiency, by accelerating the exhaust to high speed. The power imparted to the exhaust increases with the square of exhaust velocity while thrust increase is linear. Conversely, chemical rockets provide high thrust, but are limited in total impulse by the small amount of energy that can be stored chemically in the propellants.[3] Given the practical weight of suitable power sources, the acceleration from an ion thruster is frequently less than one thousandth of standard gravity. However, since they operate as electric (or electrostatic) motors, they convert a greater fraction of input power into kinetic exhaust power. Chemical rockets operate as heat engines, and Carnot's theorem limits the exhaust velocity. Ion thrust engines are practical only in the vacuum of space and cannot take vehicles through the atmosphere because ion engines do not work in the presence of ions outside the engine. Spacecraft rely on conventional chemical rockets to initially reach orbit. |
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Ion drive for aircraft imminent.
In sci.physics Robert Clark wrote:
As mentioned previously, battery-powered airplanes and helicopters do exist. As research toys; there are not as yet any electric airplanes or helicopters that could be called practical in any sense of the word. The ionic propulsion will likewise be battery-powered but at a more efficient power usage, if the ionizing wires are at the nanoscale. The greater efficiency for ionic propulsion with nanoscale wires can be confirmed with any wires at the nanoscale, not just carbon nanotubes. For example, the intense fields created by nanoscale wires in microcircuitry boards is well-known to those in the field. So anyone who has familiarity working with microcircuitry boards with nanoscale wiring could confirm this. An intense field does not automatically means motive power. Are you saying microcircuitry boards have to be lashed down to keep them from flying away? And that's all that's required. That in itself would be the game changer. Even if it's only done on a model the size of a model airplane, once it's shown that nanoscale wiring for ionic propulsion produced better power-to-thrust ratio than helicopters, that would be sufficient for this to supplant helicopters as a hovering transport method. Yeah, sure. You do know the tips of such ion generators burn away and the smaller the tip the faster they burn? Bob Clark snip -- Jim Pennino |
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