-
#340 by Vesc on 08 Dec, 2016 20:01
-
I have been away for a long time. Since Thread 7! And am getting caught up. I've seen many references to the Eagleworks AIAA paper and comments to the effect that it is published? But I've also read that it is due out in a December 2016 issue of an AIAA journal. I don't see any December 2016 issues yet on the AIAA website. Can anyone tell me me which AIAA journal this paper will be published in and when to expect to see the December 2016 issue? Or if there is already a link to the paper I would appreciate a reply with attached link.
Why does this always happen to me? Two minutes after I make the above request I find it!
http://arc.aiaa.org/doi/pdf/10.2514/1.B36120
Will be in this months' AIAA Journal of Propulsion and Power.
Oh well. In the words of E. Latella (sp?) Never mind!
-
#341 by WarpTech on 08 Dec, 2016 20:25
-
The equation below would seem to imply, that I can get thrust if I heat one end "Pin" and cool the other end, "Ploss" to form a temperature (pressure) gradient in the internal gas of a sealed cylinder of constant volume.
Have there been any experiments that test the temperature difference between the two ends?
Has such an experiment with a sealed cylinder been done? Probably not, since it would seem to violate CoM, but it doesn't.
Would this count as an experiment here: https://en.wikipedia.org/wiki/Pioneer_anomaly ?
It's a different effect. I guess it's too off topic for anyone to argue about it? I'm planning on doing this experiment, since I haven't found any data that it has been done before. It's a lot cheaper than using MW's too!
-
#342 by flux_capacitor on 08 Dec, 2016 22:43
-
The equation below would seem to imply, that I can get thrust if I heat one end "Pin" and cool the other end, "Ploss" to form a temperature (pressure) gradient in the internal gas of a sealed cylinder of constant volume.
Have there been any experiments that test the temperature difference between the two ends?
Has such an experiment with a sealed cylinder been done? Probably not, since it would seem to violate CoM, but it doesn't.
Todd, your work in progress about your PV model of the EmDrive is very interesting, but it's still like an incomplete messy puzzle to me. May I ask you to answer some questions in layman terms?
I understood the key is the asymmetric attenuation of RF power in the resonant cavity, which would trigger an accelerated reference frame near cutoff (small end).
I don't understand how an accelerated reference frame could be generated, but the asymmetric attenuation is due to the asymmetric shape of the frustum, a gradient in the ohmic losses (more heat extracted out of the cavity at one end) and evanescent waves near cutoff (at small end) carrying momentum away.
Correct?
Now, I fail to understand what is going on with photons. In your model, does the momentum of photons trapped in a tapered cavity vary according to the cross-section of the cavity (a bit like Shawyer or McCulloch but on a different theoretical basis)? Or does the speed of light vary between the two ends?
Then, you say that "the inertial center of mass-energy of the EM wave is continually shifted backwards so the cavity reacts forward" but is this inertial movement due to some mechanism triggering a variation of the momentum of travelling EM waves in a tapered cavity (see question above)? Or is the center of mass-energy of the EM wave simply shifted due to asymmetric thermal extraction outside of the cavity at one end? -
#343 by Josave on 08 Dec, 2016 22:43
-
...
We have looked at these types of transistors before. I picked up one of these for $104: http://tinyurl.com/h568esp
If they were available mounted on a finished board that only required soldering power leads, heat sink, and plugging in the coax, that would be even better!
...
Very soon the manufacturers of LDMOS transistors will be offering a full board, including also the frequency generator capable of being computer controlled in phase and frequency:
https://www.everythingrf.com/News/details/2552-plug-and-play-rf-cooking-module-reduces-time-to-market-for-appliance-oems
-
#344 by rq3 on 09 Dec, 2016 00:42
-
...
We have looked at these types of transistors before. I picked up one of these for $104: http://tinyurl.com/h568esp
If they were available mounted on a finished board that only required soldering power leads, heat sink, and plugging in the coax, that would be even better!
...
Very soon the manufacturers of LDMOS transistors will be offering a full board, including also the frequency generator capable of being computer controlled in phase and frequency:
https://www.everythingrf.com/News/details/2552-plug-and-play-rf-cooking-module-reduces-time-to-market-for-appliance-oems
These are cool. NOT. They are specified as fairly narrow band devices, to comply with ISM standards when mounted on the board (i.e., you're almost, but not quite, tuning the frustum to the source). They require tens of amps of clean direct current (beware of Lorentz forces). Their efficiency is comparable to a magnetron, so expect to shed several HUNDRED watts of heat. A magnetron is a vacuum tube, and tolerates the heat. A solid state transistor, whether LDMOS like this one or GaN like the Macom device, nah, not so much. These devices are presented on evaluation boards optimized for a 50 ohm source and load for evaluation purposes. A frustum is not a 50 ohm load. S-parameters are strictly for linear purposes normalized to the network impedance. Beware S-parameters for non-linear devices launched into non-normalized conditions. Finally, these are amplifiers, not oscillators. They have a certain gain, at a certain frequency. You still have to drive them with a source of somewhere on the order of 4 watts of microwave RF. Keep in mind that the microstrip design of these protoboards radiates an E field quite well.
Be safe. If you buy one of these devices, and build one of these amplifiers, and don't enclose it in a well shielded RF tight enclosure, you can expect to wake up the next morning with eyeballs that look like poached eggs. Forever. As a test, over-ride the interlocks on your microwave oven, stick your head inside, and turn it on medium for one minute. Don't do this. But do contemplate the result.
A magnetron power supply will kill you, no questions asked, right now and right away just from the voltages and currents involved. A high power RF transistor may not shock you to death instantly, but will do so insidiously, and it most certainly can cook you or burn you to death. Or put you into a condition where you wished you were dead.
-
#345 by WarpTech on 09 Dec, 2016 01:37
-
The equation below would seem to imply, that I can get thrust if I heat one end "Pin" and cool the other end, "Ploss" to form a temperature (pressure) gradient in the internal gas of a sealed cylinder of constant volume.
Have there been any experiments that test the temperature difference between the two ends?
Has such an experiment with a sealed cylinder been done? Probably not, since it would seem to violate CoM, but it doesn't.
Todd, your work in progress about your PV model of the EmDrive is very interesting, but it's still like an incomplete messy puzzle to me. May I ask you to answer some questions in layman terms?
I understood the key is the asymmetric attenuation of RF power in the resonant cavity, which would trigger an accelerated reference frame near cutoff (small end).
I don't understand how an accelerated reference frame could be generated, but the asymmetric attenuation is due to the asymmetric shape of the frustum, a gradient in the ohmic losses (more heat extracted out of the cavity at one end) and evanescent waves near cutoff (at small end) carrying momentum away.
Correct?
It also depends on the mode shape and how energy is distributed, and where power is dissipated. Small end or big end, at this point, is a very difficult prediction, because there is practically no temperature data to compare between experiments. You have the gist of it correct. The thrust will be in the direction of the side which has the highest magnetic pressure and lowest power dissipation. There are cases however, where apparently all the energy is at one end, TM010 mode, and there is nothing going on at the other end. This adds complexity as there's no simple rule of this end or that end.QuoteNow, I fail to understand what is going on with photons. In your model, does the momentum of photons trapped in a tapered cavity vary according to the cross-section of the cavity (a bit like Shawyer or McCulloch but on a different theoretical basis)? Or does the speed of light vary between the two ends?
In my model, the photos "are" the lines of magnetic flux. They carry momentum when coupled to charge, p = q*A. Whether it is the speed of light or the frequency of the waves that varies (not photons), is all a matter perspective. It's not one or the other as one is dependent on the other. However, the "cause" is the dissipation, that is what matters. If you think about the dissipation, not the photons, there is no ambiguity. The magnetic flux (volt-seconds) escapes where ever there is voltage drop in one direction for a period of time. The voltage drop is V = I*R, and the current will cause the flux to pass through, carrying the momentum away with it.
Now, whether that flux escapes the frustum to free space, or just gets trapped in the copper as heat, it doesn't matter. The momentum has been lost from the "inside", from the cavity.QuoteThen, you say that "the inertial center of mass-energy of the EM wave is continually shifted backwards so the cavity reacts forward" but is this inertial movement due to some mechanism triggering a variation of the momentum of travelling EM waves in a tapered cavity (see question above)? Or is the center of mass-energy of the EM wave simply shifted due to asymmetric thermal extraction outside of the cavity at one end?
Your second question would be closer. As I was questioning in my post above. There would be no argument if this were a sealed can full of pressurized air, and I punched a hole in one end to let the pressure out. Obviously, the can would move the other way. But if I have a pressurized can and I simultaneously heat the air at one end and cool it at the other end, so that it is the same gradient in pressure, it should move in the same way.
There is a magnetic pressure exerted on the frustum, and the frustum is exerting pressure on the field. The forces are balanced. Where there are voltage drops, there are "leaks" that let the pressure out. The differential pressure will cause a flow and the frustum will go the other way.
Also, in my current model, it's not just the spacial gradient. It is the 4-gradient. So the time derivative plays a big part in the thrust too. If I show that the thrust can happen with just hot air, then this will make testing EM drives very difficult since it would show they MUST be tested in a hard vacuum. On the other hand however, if I can make propulsion with hot/cold air, who needs MW's?
Very good questions. Thank you!
I have plans to do this experiment. I bought some Peltier Coolers and some USB Pressure/Temperature sensors. Now all I need is can to connect them to. -
#346 by Davinator on 09 Dec, 2016 01:56
-
A reminder, this is one thread in one section of what is a very large forum. This one is about EM Drive and applications to space flight. Everything else is off topic and we obviously have a thread for today's sad news.
-
#347 by cosmo on 09 Dec, 2016 02:06
-
Now, the good news for DIYers:
EmDrive Builders Alert - New Macom Solid State Solution - Magnetron Replacement
<snip>
This is a new ultra compact 2.5GHz solid-state narrowband microwave amp for new generations ovens: GaN Power Transistor, 18dB gain, fed with only 4W to output 300W!
<snip>
Also similar products here -
http://www.ampleon.com/products/rf-energy/
Check out the Plug and Play Evaluation Tools link (4th Paragraph)
http://www.ampleon.com/news/news-articles/Credit-card-sized-250-Watt-2.4-2.5-GHz-reference-design-targets-RF-cooking-and-industrial-heating-applications.html
Evaluation Board - 250W output
Looks like a number of semi manufacturers are getting into the power microwave market. FWIW, Ampleon was a spin-off from NXP semi.
Edit -
At this point in time, it appears the best solid state board level solution is that mentioned above by Josave, as it contains all the components (synthesizer, amps, monitoring, etc) already integrated in a package with a reasonable external control interface.
https://www.everythingrf.com/News/details/2552-plug-and-play-rf-cooking-module-reduces-time-to-market-for-appliance-oems
Also, take heed of the warnings in the post by rq3. If you don't have experience dealing with high-power microwave energy, don't mess with it! BE SAFE!
-
#348 by mwvp on 09 Dec, 2016 04:43
-
The equation below would seem to imply, that I can get thrust if I heat one end "Pin" and cool the other end, "Ploss" to form a temperature (pressure) gradient in the internal gas of a sealed cylinder of constant volume.
Have there been any experiments that test the temperature difference between the two ends?
Has such an experiment with a sealed cylinder been done? Probably not, since it would seem to violate CoM, but it doesn't.
Would this count as an experiment here: https://en.wikipedia.org/wiki/Pioneer_anomaly ?
It's a different effect. I guess it's too off topic for anyone to argue about it? I'm planning on doing this experiment, since I haven't found any data that it has been done before. It's a lot cheaper than using MW's too!
I posted this link a while back, FWIW: "Observations of an Anomalous Reversible Weight Change Effect
in a System Containing a Thermo-electric Peltier Device."
http://www.linux-host.org/energy/peltier.htm
It may well be EMD related, since, AFAIK, a Peltier is a semiconductor junction, dispersive to electron De Broglie waves.
I wonder about a potential thermal thrust effect. Isn't a thermal gradient a momentum gradient?
Should be a no-brainer for a cube-sat. To the extent any cube-sat is a no-brainer, that is. A Peltier and a heat-sink/radiator. -
#349 by spupeng7 on 09 Dec, 2016 05:20
-
IAC, Adelaide, Australia, Sept, 2017
Hi Guys,
I'm very seriously considering setting up an exhibit booth, so to demo my non cryo S band thruster happily spinning and accelerating on a rotary test rig during the conference.
Will any of you guys be going and/or will any of you have a product in the market by then?
All the best,
Phil
of course assuming my health will support that plan
Phil,
seriously bloke, this is my home town and I live 15 minutes walk from the conference center. Yes I will be there with bells on if either you or Roger can make it, what a treat. Am available as support if required and can recommend the local amenities. Sorry no reply last March, must have missed this post the first time around.
Drinks on me if you or any other emdrive folk can be here, John Newell..
Attached photo of central Adelaide.
-
#350 by TheTraveller on 09 Dec, 2016 05:53
-
Attached is now to cool a thruster to 77K without immersing it in liquid LN2.
I expect my spherical thrusters will gen around 0.6N/kW at room temp. Expect the Rs to drop around 3-4 times at 77K, which should lift the specific force to around 1.8 to 2.4N/kW.
Phil
-
#351 by TheTraveller on 09 Dec, 2016 06:03
-
IAC, Adelaide, Australia, Sept, 2017
Hi Guys,
I'm very seriously considering setting up an exhibit booth, so to demo my non cryo S band thruster happily spinning and accelerating on a rotary test rig during the conference.
Will any of you guys be going and/or will any of you have a product in the market by then?
All the best,
Phil
of course assuming my health will support that plan
Phil,
seriously bloke, this is my home town and I live 15 minutes walk from the conference center. Yes I will be there with bells on if either you or Roger can make it, what a treat. Am available as support if required and can recommend the local amenities. Sorry no reply last March, must have missed this post the first time around.
Drinks on me if you or any other emdrive folk can be here, John Newell..
Attached photo of central Adelaide.
Will cost me a min $15k to do the show. Will know by end June 2017 if it will happen.
Would be a lot lower cost to rent a suite in an adjacent hotel to do the demo. I know Dr Tajmar is going and we plan to catch up during the conference, so for sure he would spread the word that there was an EmDrive demo in an adjacent hotel suite. Also fairly simple to stand outside the entry doors and hand out a flyer.
Did talk with Roger & Gilo. They have no plans as of now to attend.
Unless someone else does a presentation at some other venue before Sept 2017, my S band thruster may be the 1st public demo. -
#352 by RERT on 09 Dec, 2016 11:07
-
I posted this link a while back, FWIW: "Observations of an Anomalous Reversible Weight Change Effect
in a System Containing a Thermo-electric Peltier Device."
http://www.linux-host.org/energy/peltier.htm
Good read! Most interesting, they seem to have stopped when needing a torsion balance to measure a horizontal force. The thing seems an order of magnitude simpler than an EMDrive, and produces 1-5 mg force, which is 10-50 microNewton. If a DIYer has a torsion balance handy, it might be easy to get somewhere with this.
Admitting I don't really understand Warptech's theory, it does seem to chime with that... -
#353 by flux_capacitor on 09 Dec, 2016 12:32
-
The equation below would seem to imply, that I can get thrust if I heat one end "Pin" and cool the other end, "Ploss" to form a temperature (pressure) gradient in the internal gas of a sealed cylinder of constant volume.
Have there been any experiments that test the temperature difference between the two ends?
Has such an experiment with a sealed cylinder been done? Probably not, since it would seem to violate CoM, but it doesn't.
Todd, your work in progress about your PV model of the EmDrive is very interesting, but it's still like an incomplete messy puzzle to me. May I ask you to answer some questions in layman terms?
I understood the key is the asymmetric attenuation of RF power in the resonant cavity, which would trigger an accelerated reference frame near cutoff (small end).
I don't understand how an accelerated reference frame could be generated, but the asymmetric attenuation is due to the asymmetric shape of the frustum, a gradient in the ohmic losses (more heat extracted out of the cavity at one end) and evanescent waves near cutoff (at small end) carrying momentum away.
Correct?
It also depends on the mode shape and how energy is distributed, and where power is dissipated. Small end or big end, at this point, is a very difficult prediction, because there is practically no temperature data to compare between experiments. You have the gist of it correct. The thrust will be in the direction of the side which has the highest magnetic pressure and lowest power dissipation. There are cases however, where apparently all the energy is at one end, TM010 mode, and there is nothing going on at the other end. This adds complexity as there's no simple rule of this end or that end.QuoteNow, I fail to understand what is going on with photons. In your model, does the momentum of photons trapped in a tapered cavity vary according to the cross-section of the cavity (a bit like Shawyer or McCulloch but on a different theoretical basis)? Or does the speed of light vary between the two ends?
In my model, the photos "are" the lines of magnetic flux. They carry momentum when coupled to charge, p = q*A. Whether it is the speed of light or the frequency of the waves that varies (not photons), is all a matter perspective. It's not one or the other as one is dependent on the other. However, the "cause" is the dissipation, that is what matters. If you think about the dissipation, not the photons, there is no ambiguity. The magnetic flux (volt-seconds) escapes where ever there is voltage drop in one direction for a period of time. The voltage drop is V = I*R, and the current will cause the flux to pass through, carrying the momentum away with it.
Now, whether that flux escapes the frustum to free space, or just gets trapped in the copper as heat, it doesn't matter. The momentum has been lost from the "inside", from the cavity.QuoteThen, you say that "the inertial center of mass-energy of the EM wave is continually shifted backwards so the cavity reacts forward" but is this inertial movement due to some mechanism triggering a variation of the momentum of travelling EM waves in a tapered cavity (see question above)? Or is the center of mass-energy of the EM wave simply shifted due to asymmetric thermal extraction outside of the cavity at one end?
Your second question would be closer. As I was questioning in my post above. There would be no argument if this were a sealed can full of pressurized air, and I punched a hole in one end to let the pressure out. Obviously, the can would move the other way. But if I have a pressurized can and I simultaneously heat the air at one end and cool it at the other end, so that it is the same gradient in pressure, it should move in the same way.
There is a magnetic pressure exerted on the frustum, and the frustum is exerting pressure on the field. The forces are balanced. Where there are voltage drops, there are "leaks" that let the pressure out. The differential pressure will cause a flow and the frustum will go the other way.
Also, in my current model, it's not just the spacial gradient. It is the 4-gradient. So the time derivative plays a big part in the thrust too. If I show that the thrust can happen with just hot air, then this will make testing EM drives very difficult since it would show they MUST be tested in a hard vacuum. On the other hand however, if I can make propulsion with hot/cold air, who needs MW's?
Very good questions. Thank you!
I have plans to do this experiment. I bought some Peltier Coolers and some USB Pressure/Temperature sensors. Now all I need is can to connect them to.
I look forward to watch your presentation given at the Estes Park workshop once it is available on the SSI website. I am sure many readers here do want to understand your model better; but very few people has the training to grasp all of the PV maths.
I think also updating the wiki article about your model would be good thing, in particular explaining:
• What is exactly "dispersion" (group velocity dispersion?) and what is its relation with the creation of an artificial accelerated reference frame (i.e. which is a gravitational field generator!) and the notsosureofit Hypothesis,
• The difference between dissipation and attenuation in a cavity (I imagine attenuation of the EM energy as a consequence of power dissipation?),
• And why just extracting heat out of one particular end of a resonant cavity (or even, as recently suggested, out of a cylindrical metal can filled with just gas and no EM waves!), apparently a trivial thermodynamic process that does not seem at all related to advanced concepts like propellantless interstellar travel or flying cars, could generate such things as "an accelerated reference frame" and a "gravitoelectric field". -
#354 by kaublezw on 09 Dec, 2016 14:31
-
I find it hard to believe that our ticket to the stars is as easy as creating a heat gradient on an enclosed metal cavity. This could've been done easily over 100 years ago. Surely such a discovery would've been stumbled upon accidentally by now.
But please prove me wrong. 
-
#355 by SeeShells on 09 Dec, 2016 14:39
-
...
We have looked at these types of transistors before. I picked up one of these for $104: http://tinyurl.com/h568esp
If they were available mounted on a finished board that only required soldering power leads, heat sink, and plugging in the coax, that would be even better!
...
Very soon the manufacturers of LDMOS transistors will be offering a full board, including also the frequency generator capable of being computer controlled in phase and frequency:
https://www.everythingrf.com/News/details/2552-plug-and-play-rf-cooking-module-reduces-time-to-market-for-appliance-oems
These are cool. NOT. They are specified as fairly narrow band devices, to comply with ISM standards when mounted on the board (i.e., you're almost, but not quite, tuning the frustum to the source). They require tens of amps of clean direct current (beware of Lorentz forces). Their efficiency is comparable to a magnetron, so expect to shed several HUNDRED watts of heat. A magnetron is a vacuum tube, and tolerates the heat. A solid state transistor, whether LDMOS like this one or GaN like the Macom device, nah, not so much. These devices are presented on evaluation boards optimized for a 50 ohm source and load for evaluation purposes. A frustum is not a 50 ohm load. S-parameters are strictly for linear purposes normalized to the network impedance. Beware S-parameters for non-linear devices launched into non-normalized conditions. Finally, these are amplifiers, not oscillators. They have a certain gain, at a certain frequency. You still have to drive them with a source of somewhere on the order of 4 watts of microwave RF. Keep in mind that the microstrip design of these protoboards radiates an E field quite well.
Be safe. If you buy one of these devices, and build one of these amplifiers, and don't enclose it in a well shielded RF tight enclosure, you can expect to wake up the next morning with eyeballs that look like poached eggs. Forever. As a test, over-ride the interlocks on your microwave oven, stick your head inside, and turn it on medium for one minute. Don't do this. But do contemplate the result.
A magnetron power supply will kill you, no questions asked, right now and right away just from the voltages and currents involved. A high power RF transistor may not shock you to death instantly, but will do so insidiously, and it most certainly can cook you or burn you to death. Or put you into a condition where you wished you were dead.
VERY WELL SAID!
A great summary defining both the magnetron and SS device differences and the dangers of microwave energy production in both.
It needs to be said more often, I worry about someone getting seriously harmed or worse.
Shell -
#356 by Monomorphic on 09 Dec, 2016 15:13
-
They are specified as fairly narrow band devices, to comply with ISM standards when mounted on the board (i.e., you're almost, but not quite, tuning the frustum to the source).
They have a certain gain, at a certain frequency. You still have to drive them with a source of somewhere on the order of 4 watts of microwave RF.
These evaluation boards have an integrated 2.4Ghz signal generator, with pre-driver, driver, and final stage. It is likely tunable from 2.4Ghz to 2.5Ghz, as the MACOM. Should be easy to build a frustum tuned within those margins.
-
#357 by flux_capacitor on 09 Dec, 2016 15:57
-
I find it hard to believe that our ticket to the stars is as easy as creating a heat gradient on an enclosed metal cavity. This could've been done easily over 100 years ago. Surely such a discovery would've been stumbled upon accidentally by now.
But please prove me wrong.
The more I read it, the more it seems we would already have created a warp drive heating canned food in a microwave oven!
Joking aside, WarpTech's theory is much more appealing when one consider the EM wave velocity or momentum variation mechanism triggering a variable refractive index, which is an accelerated frame of reference, thus an artificially generated gravitational potential. In this case, WarpTech's EmDrive would be… a reactionless warp drive. -
#358 by Bob012345 on 09 Dec, 2016 16:05
-
The equation below would seem to imply, that I can get thrust if I heat one end "Pin" and cool the other end, "Ploss" to form a temperature (pressure) gradient in the internal gas of a sealed cylinder of constant volume.
Have there been any experiments that test the temperature difference between the two ends?
Has such an experiment with a sealed cylinder been done? Probably not, since it would seem to violate CoM, but it doesn't.
Would this count as an experiment here: https://en.wikipedia.org/wiki/Pioneer_anomaly ?
It's a different effect. I guess it's too off topic for anyone to argue about it? I'm planning on doing this experiment, since I haven't found any data that it has been done before. It's a lot cheaper than using MW's too!
I posted this link a while back, FWIW: "Observations of an Anomalous Reversible Weight Change Effect
in a System Containing a Thermo-electric Peltier Device."
http://www.linux-host.org/energy/peltier.htm
It may well be EMD related, since, AFAIK, a Peltier is a semiconductor junction, dispersive to electron De Broglie waves.
I wonder about a potential thermal thrust effect. Isn't a thermal gradient a momentum gradient?
Should be a no-brainer for a cube-sat. To the extent any cube-sat is a no-brainer, that is. A Peltier and a heat-sink/radiator.
If the Cubesat works, are people going to claim it just interacts with Earth's magnetic field? Has anyone done the calculations to show that won't explain the thrust as just a Lorentz force? -
#359 by RERT on 09 Dec, 2016 16:15
-
Hmm. Took a few million years from fire to the steam engine. Maybe there were extenuating circumstances, or perhaps we just blame homo habilis for most of that...
