URL?
Quote from: gospacex on 06/26/2010 06:08 pmURL?My companies website is still under construction, but it's http://www.gravitecinc.com
Quote from: hec031 on 06/26/2010 06:22 pmQuote from: gospacex on 06/26/2010 06:08 pmURL?My companies website is still under construction, but it's http://www.gravitecinc.comHow large is your vacuum chamber? Generally speaking, when in a vacuum, these devices do develop a thrust by electrostatically reacting against the chamber
Need to also clarify that the force is not oscillatory or transitory, it's steady state and displaces the device from it's resting Level Pendulum position forward and up where it holds this position for as long as power is being applied to the device.
Quote from: hec031 on 06/26/2010 10:01 pmNeed to also clarify that the force is not oscillatory or transitory, it's steady state and displaces the device from it's resting Level Pendulum position forward and up where it holds this position for as long as power is being applied to the device.Have you flipped it over?
This last winter under a government funded effort we tested our Asymmetrical capacitor devices in both Air (atmospheric conditions) and Vacuum ( lower than 4.5x10^-6 Torr). In both test cases the results were identical. The devices showed a force averaging 2mN.Currently we are working on trying to get someone to confirm the work but every organization that has been approached has shown great reservations in being the one to confirm the findings. The same issue keeps being sighted. While no researcher that has seen our final report has been able to identify the source or cause of the force, they retain the position that the effect must have a conventional origin despite their failure to identify it.That puts me in a catch 22 at the moment. In either case I needed a fresh perspective and ideas so I figured this would be a great place to get it at.Feel free to comment, make suggestion or ask questions. I will warn you that while the work is not secret, it is proprietary and non of the people and organizations involved want anyone to know who they are at the moment. The choice is mind, but I rather not burn any bridges, just yet.I'll do my best to answer questions.
Quote from: hec031 on 06/26/2010 04:32 pmThis last winter under a government funded effort we tested our Asymmetrical capacitor devices in both Air (atmospheric conditions) and Vacuum ( lower than 4.5x10^-6 Torr). In both test cases the results were identical. The devices showed a force averaging 2mN.Currently we are working on trying to get someone to confirm the work but every organization that has been approached has shown great reservations in being the one to confirm the findings. The same issue keeps being sighted. While no researcher that has seen our final report has been able to identify the source or cause of the force, they retain the position that the effect must have a conventional origin despite their failure to identify it.That puts me in a catch 22 at the moment. In either case I needed a fresh perspective and ideas so I figured this would be a great place to get it at.Feel free to comment, make suggestion or ask questions. I will warn you that while the work is not secret, it is proprietary and non of the people and organizations involved want anyone to know who they are at the moment. The choice is mind, but I rather not burn any bridges, just yet.I'll do my best to answer questions.Hmm. Well, I don't know what you meant so googled it:"Asymmetrical Capacitor Thrusters have been proposed as a source of propulsion. For over eighty years, it has been known that a thrust results when a high voltage is placed across an asymmetrical capacitor, when that voltage causes a leakage current to flow. However, there is surprisingly little experimental or theoretical data explaining this effect. This paper reports on the results of tests of several Asymmetrical Capacitor Thrusters (ACTs). The thrust they produce has been measured for various voltages, polarities, and ground configurations and their radiation in the VHF range has been recorded. These tests were performed at atmospheric pressure and at various reduced pressures."http://gltrs.grc.nasa.gov/citations/all/cr-2004-213312.htmlAnd:"One description I read says that the high voltage of the top conductor ionizes air (by removing or adding electrons?), which is then attracted to the bottom conductor. On its way to the bottom conductor it collides with neutral air molecules, and imparts momentum to them. The neutral molecules are not attracted to the conductor, so they just keep on moving in the same direction, creating the wind. The charged particles keep going until they hit the bottom electrode, give up their charge, and become free-floating neutral particles again."http://www.physicsforums.com/showthread.php?t=80986I know you can not create a perfect vacuum. But it seems possible that if you reduce the amount air by making a vacuum, it might reasonable that the effect should affect it in some way. Or if you increase the air pressure it should similarly have some effect. Or if you change the content of the air into say hydrogen gas, one should see some effect.But my question is other some science value [perhaps earth shattering in it's importance] what use would this have?I assume the importance is you get propulsion without using rocket fuel, but it seems this has little practical importance unless one can get a lot of propulsion- that's it's an efficient means of moving.
There are two big values to the research, if and when confirmed which will take years I'm sure. First it's the fact that it would open new avenues in physics. New paths new phenomenology. Second on the practical side the device is generating 24mN/W, which means it far exceeds any known form of Electric Space Propulsion. Then the issue is, if it's scalable and we have already found one sure way were we can scale the force linearly with power. Another simpler way to achieve scalability is going to be tested soon, that is simpler and therefore more practical. There are many types of "Electric Space Propulsion", though all involve using propellent. And since this doesn't use a propellent is seem rather difficult to compared it. The significant of all known "Electric Space Propulsion" is speed in which it can propel mass. You aren't propelling mass, so how and why would you compare to them.Most common "Electric Space Propulsion" such ion engine have very little thrust. And that is their disadvantage as compared to chemical rockets.A ion engine compares favorably with a chemical rocket not because of it's thrust but because it uses less propellent mass more efficiently.So instead comparing to an ion engine, why, other than it provides low thrust, not compare it to a chemical rocket. Or a solar sail. Or numerous other ways of moving in a vacuum."In one simulation by a major Aerospace company they Calculated that using this form of propulsion they could move a spacecraft from low earth orbit to Mars Low orbit and back in 21 days. In another simulation they could move a satellite from low earth orbit to high earth orbit in one hour. So there are a lot of practical applications that could use this kind of performance."Ok. But since you haven't scale it up, it can't move spacecraft.
This isn't a new concept, it's pretty old, and there's a lot of people aware of it and have tested it (myself included). The thrust produced does fall off with atmospheric pressure, so there is a very significant ion wind component to the thrust, however I've never seen any tests of it at pressures equivalent to low earth orbit. If you are so sure it works, then I'd suggest you build a CubeSat that uses one of these thrusters, fed by solar cells. If you can maintain the 24 mN/W in orbit, then you should easily be able to demonstrate that with significant orbital changes. Publishing that data would be undeniable proof.
Quote from: mlorrey on 06/28/2010 06:43 amThis isn't a new concept, it's pretty old, and there's a lot of people aware of it and have tested it (myself included). The thrust produced does fall off with atmospheric pressure, so there is a very significant ion wind component to the thrust, however I've never seen any tests of it at pressures equivalent to low earth orbit. If you are so sure it works, then I'd suggest you build a CubeSat that uses one of these thrusters, fed by solar cells. If you can maintain the 24 mN/W in orbit, then you should easily be able to demonstrate that with significant orbital changes. Publishing that data would be undeniable proof.Currently the plan is to have the results independently verified, then presented at an industry conference and publish a paper in a peer reviewed journal. Eventually as you suggest we would like to see it tested in orbit. Just a note. There is no ion wind to our devices. While I used Asymmetric capacitor in the title of this post, our test device are unique examples of this technology. Ion wind is not even under debate by the experts that are looking at the work. In our case the performance did not change from atmospheric to high vacuum, it remains the same and constant.I appreciate your suggestion, but we are still a few steps away from any kind of in orbit testing, but I'm sure it will come.
Interesting. Have you folks tried purging the vacuum chamber with different compositions of gasses before vacuum pumping? For instance purging with helium and run the experiment. And then purge with nitrogen and run the same experiment. And then try one with an obvious electrical conductivity, like Neon.If you get different results it could be an 'ion wind' effect. If you get the same results, it could be what you are looking for. Anyways, it maybe worth a try. It might be interesting to see if there is any correlation to the composition of your purge gas.I woulld even try a run in Sulfur Hexaflouride gas which is a common high voltage insulating gas used in high voltage switching gear. If you get exactly the same force readings under all of those conditions I think you can definitively rule out ion wind.
Quote from: hec031 on 06/28/2010 11:00 amQuote from: mlorrey on 06/28/2010 06:43 amThis isn't a new concept, it's pretty old, and there's a lot of people aware of it and have tested it (myself included). The thrust produced does fall off with atmospheric pressure, so there is a very significant ion wind component to the thrust, however I've never seen any tests of it at pressures equivalent to low earth orbit. If you are so sure it works, then I'd suggest you build a CubeSat that uses one of these thrusters, fed by solar cells. If you can maintain the 24 mN/W in orbit, then you should easily be able to demonstrate that with significant orbital changes. Publishing that data would be undeniable proof.Currently the plan is to have the results independently verified, then presented at an industry conference and publish a paper in a peer reviewed journal. Eventually as you suggest we would like to see it tested in orbit. Just a note. There is no ion wind to our devices. While I used Asymmetric capacitor in the title of this post, our test device are unique examples of this technology. Ion wind is not even under debate by the experts that are looking at the work. In our case the performance did not change from atmospheric to high vacuum, it remains the same and constant.I appreciate your suggestion, but we are still a few steps away from any kind of in orbit testing, but I'm sure it will come.Hector:I have a few questions for you:1. Does your thruster device work off dc or ac power? 2. If dc, what is the magnitude of the drive voltage at the noted 2.0 milli-Newtons output? If ac, what is the frequency and peak voltage at the same thrust level? Is there a differnce in thrust production between the ac and dc cases for a given input voltage??3. Is the power supply for the device mounted with the device, i.e., is it battery powered and therefore self-contianed with the device, or do you supply power to the device remotely via a twisted pair or coaxial cable?Thanks much.
Quote from: Star-Drive on 06/28/2010 02:44 pmQuote from: hec031 on 06/28/2010 11:00 amQuote from: mlorrey on 06/28/2010 06:43 amThis isn't a new concept, it's pretty old, and there's a lot of people aware of it and have tested it (myself included). The thrust produced does fall off with atmospheric pressure, so there is a very significant ion wind component to the thrust, however I've never seen any tests of it at pressures equivalent to low earth orbit. If you are so sure it works, then I'd suggest you build a CubeSat that uses one of these thrusters, fed by solar cells. If you can maintain the 24 mN/W in orbit, then you should easily be able to demonstrate that with significant orbital changes. Publishing that data would be undeniable proof.Currently the plan is to have the results independently verified, then presented at an industry conference and publish a paper in a peer reviewed journal. Eventually as you suggest we would like to see it tested in orbit. Just a note. There is no ion wind to our devices. While I used Asymmetric capacitor in the title of this post, our test device are unique examples of this technology. Ion wind is not even under debate by the experts that are looking at the work. In our case the performance did not change from atmospheric to high vacuum, it remains the same and constant.I appreciate your suggestion, but we are still a few steps away from any kind of in orbit testing, but I'm sure it will come.Hector:I have a few questions for you:1. Does your thruster device work off dc or ac power? 2. If dc, what is the magnitude of the drive voltage at the noted 2.0 milli-Newtons output? If ac, what is the frequency and peak voltage at the same thrust level? Is there a differnce in thrust production between the ac and dc cases for a given input voltage??3. Is the power supply for the device mounted with the device, i.e., is it battery powered and therefore self-contianed with the device, or do you supply power to the device remotely via a twisted pair or coaxial cable?Thanks much.DC, +41.5Kv@2uA and -41.4Kv@6uA. While the device is exposed to the vacuum, the Electrodes are not. The Electrodes are fully encapsulated and operating in their own environment, this is why the performance does not change regardless of what's on the outside of the device. Currently the device is powered via a high voltage feedthrough and umbilical cable. A self contained power supply and source is a few steps ahead of were we are at the moment, but it is one of our future experimental goals.