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#800 by VAXHeadroom on 31 Oct, 2015 13:23
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...
How much Force do you need a cubesat EMDrive to deliver? Knowing the Force desired then the needed Rf watts can be calculated. Your job to deliver those Rf watts and ensure there is enough primary power available. Can design to many dimensions knowing the Rf drive freq, which will need to real time track lowest VSWR or lowest reflected power to achieve and hold resonance. I assume it needs to fit inside 1 cube being 100mmx100mmx100mm?
To fit in a 12u cubesat, large dia can be up to 20cm with length up to 36cm. To accelerate a 10Kg cubesat at 10mm/s would take...what... 100mN? I'm guessing on the math here - too late at night - I'm probably off by some powers of 10... We can give you a KW for several minutes once per orbit, only limit is how hot the batteries get and how far we discharge them. More than a 20% depth of discharge will limit their life, but this is probably a limited life test anyway (not a multi-year mission) so we can maybe run them harder and/or pack in more batteries to give us more instantaneous power...
Quick analysis suggest the 20cm big end limitation reduces the Df ( F = (2 Df unloadedQ P) / c ) quite a bit. But working on that limitation I get a highly optimised small end of 14.95cm and length of 15.07cm (mode TE011 @ 2.45GHz), with spherical end plates, using a 20% solid state amp conversion efficiency to Rf and 1kW power input could deliver, at a conservative unloaded Q of 50,000 (25,000 as measured loaded Q) around 40mN, generating say 4mm/sec acceleration with a 10kg mass.
Let's get our physics right. 40 mN acting on a 10 kg object would generate an acceleration of 4 mm per second per second. So assuming 1) you could hold spacecraft attitude, and 2) other forces on the satellite are much less than 40 mN your velocity would change (for example) 4 mm per second if you could hold 1 kW for one second. Is that detectable?
These systems can hold an attitude of less than 1 deg.
dV of 10mm/s over 30 minutes is detectable, so 4mm/s/s accel is WAY above the noise floor.Vax,
A X band 1U EMDrive thruster delivering 2mN of thrust for 12W draw is doable. Depending on the power available the Rf Watts can go up as would the thrust.
Do you need constant or short term thrust?
What is the desired mN thrust?
What is the mass budget for the thruster?
How much power can you supply to meet the thrust requirements?
Potentially the thrust may be able to be vectored +-10 deg in 2 axis. Is this helpful?
Available on-orbit average power is ~50W, and short duration power draw can be up to about 1KW. We haven't worked the heat dissipation designs yet. Constant power by the avionics is about 15W, so a constant 35W can be available to the payload, but as I said it can be provided in short bursts of up to a KW.
I can see both low power constant thrust and burst high thrust being extremely useful. That fact that you could throttle the thrust with this design is a HUGE advantage - one not possible on anything at the moment, and one I'd not thought of before!.
As noted above 10mN of thrust is probably the minimum we'd want to target as a maximum to insure a deterministic test. Being able to turn it down for long duration tests would also be a great test.
Mass can be probably 3Kg including the amplifier. Remember the amplifier doesn't need the aluminum heatsink you see on most systems
We do have to get the heat out somehow, but with the new GaN components they get really efficient and until you get to 100s of W of rf power it's not going to be much of a concern.
I'm not sure thrust vectoring is useful for the first test, but in the long term definitely!
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#801 by Prunesquallor on 31 Oct, 2015 13:58
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I have made my credentials known, I'm not an amateur, and this would not be an amateur test. The change of velocity resulting from thrust causes the ground to see a Doppler shift in the rf carrier, detectable down to a deltaV of single digit mm/s. This change needs to occur in a pretty short period of time (minutes) to insure a significant signal to noise ratio in the rf shift (if it happens too slowly it can look like thermal drift of the S-Band amplifier). This means all the hard part (large, expensive) of the test and measurement equipment is on the ground. A second means of measurement is using NASA Goddard's laser measurement system - all we really have to do for that is provide a retro-reflector on the spacecraft. They can do both position and velocity measurements out to the moon (they do this for LRO all the time), but I'll have to find out what their measurement and resolution limits are......
How much Force do you need a cubesat EMDrive to deliver? Knowing the Force desired then the needed Rf watts can be calculated. Your job to deliver those Rf watts and ensure there is enough primary power available. Can design to many dimensions knowing the Rf drive freq, which will need to real time track lowest VSWR or lowest reflected power to achieve and hold resonance. I assume it needs to fit inside 1 cube being 100mmx100mmx100mm?
To fit in a 12u cubesat, large dia can be up to 20cm with length up to 36cm. To accelerate a 10Kg cubesat at 10mm/s would take...what... 100mN? I'm guessing on the math here - too late at night - I'm probably off by some powers of 10... We can give you a KW for several minutes once per orbit, only limit is how hot the batteries get and how far we discharge them. More than a 20% depth of discharge will limit their life, but this is probably a limited life test anyway (not a multi-year mission) so we can maybe run them harder and/or pack in more batteries to give us more instantaneous power...
I'm not sure where you are going here, mm/s is a velocity, not an acceleration.
I have made my concerns about an amateur space test known previously. In my opinion, the disturbing orbital forces, thermal and EM effects on a satellite this small may not be appreciably smaller than the effects folks are trying to eliminate in the lab.
What would you conclude from a cubesat test that doesn't give detectable results?
Regarding disturbing forces, I calculate that the atmospheric drag that could be experienced by a satellite at 300 km altitude to be around 2 mN/m^2. (Assumes F10.7=150, Kp=5, Cd=2.2). At 400 km it would be down to 0.3 mN/m^2. -
#802 by TheTraveller on 31 Oct, 2015 14:09
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Vax,
Your 10mN at 35W max input power requirements appears to be doable. Going to pulsed op at upto 50mN seems doable. 3kg is heaps of mass budget. All the electronics would be on one cubesat pcb with the frustum mounted and secured to the 1u modules frame. What g and vibration freq rates will the thruster and mounting system need to be designed to handle?
What are the processes to move forward, what are the precursor qualification requirements and what are the time frames as an overview?
Yes of course I need to do the rotary demo rig. That is a unspoken given requirement. Despite others opinion here, the EMDrive does work and this cubesat thruster is really doable.
It is my intention to start commercial sales of EMDrives, so the cubesat project will be done with commercial sales as the objective. It will be a high quality and high fidelity build. -
#803 by VAXHeadroom on 31 Oct, 2015 14:25
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I have made my credentials known, I'm not an amateur, and this would not be an amateur test. The change of velocity resulting from thrust causes the ground to see a Doppler shift in the rf carrier, detectable down to a deltaV of single digit mm/s. This change needs to occur in a pretty short period of time (minutes) to insure a significant signal to noise ratio in the rf shift (if it happens too slowly it can look like thermal drift of the S-Band amplifier). This means all the hard part (large, expensive) of the test and measurement equipment is on the ground. A second means of measurement is using NASA Goddard's laser measurement system - all we really have to do for that is provide a retro-reflector on the spacecraft. They can do both position and velocity measurements out to the moon (they do this for LRO all the time), but I'll have to find out what their measurement and resolution limits are......
How much Force do you need a cubesat EMDrive to deliver? Knowing the Force desired then the needed Rf watts can be calculated. Your job to deliver those Rf watts and ensure there is enough primary power available. Can design to many dimensions knowing the Rf drive freq, which will need to real time track lowest VSWR or lowest reflected power to achieve and hold resonance. I assume it needs to fit inside 1 cube being 100mmx100mmx100mm?
To fit in a 12u cubesat, large dia can be up to 20cm with length up to 36cm. To accelerate a 10Kg cubesat at 10mm/s would take...what... 100mN? I'm guessing on the math here - too late at night - I'm probably off by some powers of 10... We can give you a KW for several minutes once per orbit, only limit is how hot the batteries get and how far we discharge them. More than a 20% depth of discharge will limit their life, but this is probably a limited life test anyway (not a multi-year mission) so we can maybe run them harder and/or pack in more batteries to give us more instantaneous power...
I'm not sure where you are going here, mm/s is a velocity, not an acceleration.
I have made my concerns about an amateur space test known previously. In my opinion, the disturbing orbital forces, thermal and EM effects on a satellite this small may not be appreciably smaller than the effects folks are trying to eliminate in the lab.
What would you conclude from a cubesat test that doesn't give detectable results?
Regarding disturbing forces, I calculate that the atmospheric drag that could be experienced by a satellite at 300 km altitude to be around 2 mN/m^2. (Assumes F10.7=150, Kp=5, Cd=2.2). At 400 km it would be down to 0.3 mN/m^2.
Those numbers look reasonable to me at first glance
This would be only about 0.5m^2 for the solar panels and generally they would be body mounted and kept normal to the sun, so they do contribute to the drag for part of the orbit. The satellite body for a 6u or 12u is 30cmx37cm so only about 0.1m^2 in cross section... (caution: ascii art follows )
___ ___ ___ _ ___ ___ ___ <-- solar arrays
| |
| | <-- satellite body ^
| | | sun vector
we do have a solar array drive available, and if we use it, then the bottom of the satellite can stay pointed at the Earth and the body rotates about the vertical axis (in the drawing) once per orbit. Gives us slightly higher power and provides constant earth pointing...
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#804 by Prunesquallor on 31 Oct, 2015 15:13
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I have made my credentials known, I'm not an amateur, and this would not be an amateur test. The change of velocity resulting from thrust causes the ground to see a Doppler shift in the rf carrier, detectable down to a deltaV of single digit mm/s. This change needs to occur in a pretty short period of time (minutes) to insure a significant signal to noise ratio in the rf shift (if it happens too slowly it can look like thermal drift of the S-Band amplifier). This means all the hard part (large, expensive) of the test and measurement equipment is on the ground. A second means of measurement is using NASA Goddard's laser measurement system - all we really have to do for that is provide a retro-reflector on the spacecraft. They can do both position and velocity measurements out to the moon (they do this for LRO all the time), but I'll have to find out what their measurement and resolution limits are......
How much Force do you need a cubesat EMDrive to deliver? Knowing the Force desired then the needed Rf watts can be calculated. Your job to deliver those Rf watts and ensure there is enough primary power available. Can design to many dimensions knowing the Rf drive freq, which will need to real time track lowest VSWR or lowest reflected power to achieve and hold resonance. I assume it needs to fit inside 1 cube being 100mmx100mmx100mm?
To fit in a 12u cubesat, large dia can be up to 20cm with length up to 36cm. To accelerate a 10Kg cubesat at 10mm/s would take...what... 100mN? I'm guessing on the math here - too late at night - I'm probably off by some powers of 10... We can give you a KW for several minutes once per orbit, only limit is how hot the batteries get and how far we discharge them. More than a 20% depth of discharge will limit their life, but this is probably a limited life test anyway (not a multi-year mission) so we can maybe run them harder and/or pack in more batteries to give us more instantaneous power...
I'm not sure where you are going here, mm/s is a velocity, not an acceleration.
I have made my concerns about an amateur space test known previously. In my opinion, the disturbing orbital forces, thermal and EM effects on a satellite this small may not be appreciably smaller than the effects folks are trying to eliminate in the lab.
What would you conclude from a cubesat test that doesn't give detectable results?
Regarding disturbing forces, I calculate that the atmospheric drag that could be experienced by a satellite at 300 km altitude to be around 2 mN/m^2. (Assumes F10.7=150, Kp=5, Cd=2.2). At 400 km it would be down to 0.3 mN/m^2.
Those numbers look reasonable to me at first glance
This would be only about 0.5m^2 for the solar panels and generally they would be body mounted and kept normal to the sun, so they do contribute to the drag for part of the orbit. The satellite body for a 6u or 12u is 30cmx37cm so only about 0.1m^2 in cross section... (caution: ascii art follows )
___ ___ ___ _ ___ ___ ___ <-- solar arrays
| |
| | <-- satellite body ^
| | | sun vector
we do have a solar array drive available, and if we use it, then the bottom of the satellite can stay pointed at the Earth and the body rotates about the vertical axis (in the drawing) once per orbit. Gives us slightly higher power and provides constant earth pointing...
So the frontal area can vary from 0.1 to 0.6 m^2? So in the lower orbit, the drag could vary from 0.2 to 1.2 mN. We would want to establish that this is a good order of magnitude or two below the expected thrust. -
#805 by Star-Drive on 31 Oct, 2015 15:21
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Doesn't anyone here have any reply at all to the substance of this paper? Just throwing out insults without providing any justification for the insults isn't very persuasive.
As far as I can tell, the experiment is just measuring the Lorentz force on a device with a current running through it due to the Earth's magnetic field. They point out in the Appendix that due to different grounding points in the null and resonating cavity tests, the Lorentz force may not have been correctly accounted for in the Eagleworks experiment. This just adds one more possible explanation of experimental error that could be the real cause for the small thrust measured by Eagleworks.
This is a paper explaining why the emdrive thrust is just an error in the experiment design. It could use a bit more rigor in parts, but its point is to demonstrate that a significant source of error exists, not to precisely measure the magnitude, which would require them to have access to the original experiment equipment.
To reiterate, this paper claims (reasonably) that the measured thrust is an experimental error, and suggests an incorrect calibration of the Lorentz force effect on the setup as the cause of the error.
All:
I wish I could show you all the pictures I've taken on how we saluted and mitigated the issues raised by our EW Lab's Blue-Ribbon PhD panel and now Potomac-Neuron's paper, on the possible Lorentz force interactions. That being the Lorentz Interactions with the dc currents on the EW torque pendulum (TP) with the stray magnetic fields from the torque pendulum's first generation open-face magnetic damper and the Earth's geomagnetic field, but I can't due to the restrictive NASA press release rules now applied to the EW Lab.
However since I still can't show you this supporting data until the EW Lab gets our next peer-reviewed lab paper published, I will tell you that we first built and installed a 2nd generation, closed face magnetic damper that reduced the stray magnetic fields in the vacuum chamber by at least an order of magnitude and any Lorentz force interactions it could produce. I also changed up the torque pendulum's grounding wire scheme and single point ground location to minimize ground loop current interactions with the remaining stray magnetic fields and unbalanced dc currents from the RF amplifier when its turned on. This reduced the Lorentz force interaction to less than 2 micro-Newton (uN) for the dummy load test. Finally we rebuilt the copper frustum test article so that it is now fully integrated with the RF VCO, PLL, 100W RF amp, dual directional coupler, 3-stub tuner and connecting coax cables, then mounted this integrated test article at the opposite end of the torque pendulum, as far away as possible from the 2nd generation magnetic damper where only the required counterbalance weights now reside. Current null testing with both the 50 ohm dummy load and with the integrated test article rotated 90 degrees with respect to the TP sensitive axis now show less than one uN of Lorentz forces on the TP due to dc magnetic interactions with the local environment even when drawing the maximum RF amp dc current of 12 amps.
Given all of the above TP wiring and test article modifications with respect to our 2014 AIAA/JPC paper design baseline needed to address these Lorentz force magnetic interaction issues, we are still seeing over 100uN of force with 80W of RF power going into the frustum running in the TM212 resonant mode, now in both directions, dependent on the direction of the mounted integrated test article on the TP. However these new plus and minus thrust signatures are still contaminated by thermally induced TP center of gravity (cg) zero-thrust baseline shifts brought on by the expansion of the copper frustum and aluminum RF amp and its heat sink when heated by the RF, even though these copper and aluminum cg shifts are now fighting each other. (Sadly these TP cg baseline shifts are ~3X larger in-vacuum than in-air due to the better insulating qualities of the vacuum, so the in-vacuum thrust runs look very thermally contaminated whereas the in-air run look very impulsive.) So we have now developed an analytical tool to help separate the EM-Drive thrust pulse waveform contributions from the thermal expansion cg induced baseline shifts of the TP. Not being satisfied with just this analytical impulsive vs thermal signal separation approach, we are now working on a new integrated test article subsystem mounting arrangement with a new phase-change thermal management subsystem that should mitigate this thermally induced TP cg baseline shift problem once and for-all.
And yet the anomalous thrust signals remain...
Best, Paul March -
#806 by Prunesquallor on 31 Oct, 2015 15:32
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...
And yet the anomalous thrust signals remain...
Best, Paul March
Excelsior! -
#807 by Blaine on 31 Oct, 2015 15:56
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High quality indeed! Good things are to come. I can feel it.
...
And yet the anomalous thrust signals remain...
Best, Paul March
Excelsior! -
#808 by Star-Drive on 31 Oct, 2015 16:00
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Vax,
Your 10mN at 35W max input power requirements appears to be doable. Going to pulsed op at upto 50mN seems doable. 3kg is heaps of mass budget. All the electronics would be on one cubesat pcb with the frustum mounted and secured to the 1u modules frame. What g and vibration freq rates will the thruster and mounting system need to be designed to handle?
What are the processes to move forward, what are the precursor qualification requirements and what are the time frames as an overview?
Yes of course I need to do the rotary demo rig. That is a unspoken given requirement. Despite others opinion here, the EMDrive does work and this cubesat thruster is really doable.
It is my intention to start commercial sales of EMDrives, so the cubesat project will be done with commercial sales as the objective. It will be a high quality and high fidelity build.
Traveler:
We looked at using a 3U CubeSat as a means of validating the EmDrive physics, but the cost just for the required parts to build it is still well beyond our current means, even considering that the EW Lab could get a semi-free ride into orbit on one of the ISS resupply runs. (The ISS can and does launch 3U CubeSats from the ISS Japanese lab module.) Since you are considering selling CubeSats commercially, have you priced out how much a 3U at 3kg, 6U at 6kg and 12U at 12kg CubeSat would cost to have it put into orbit even using secondary payload status on flights of opportunity?
I'm curious...
Best, Paul March -
#809 by Eer on 31 Oct, 2015 16:08
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All:
I wish I could show you all the pictures I've taken ... but I can't due to the restrictive NASA press release rules now applied to the EW Lab.
However since I still can't show you this supporting data ...
...
And yet the anomalous thrust signals remain...
Best, Paul March
Thank you so much for this very informative non-report. I REALLY hope no one gets cross-wise with you.
It's heartening to hear that suspense remains and has not, yet, been quenched. -
#810 by Corlock Striker on 31 Oct, 2015 16:48
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Given all of the above TP wiring and test article modifications with respect to our 2014 AIAA/JPC paper design baseline needed to address these Lorentz force magnetic interaction issues, we are still seeing over 100uN of force with 80W of RF power going into the frustum running in the TM212 resonant mode, now in both directions, dependent on the direction of the mounted integrated test article on the TP. However these new plus and minus thrust signatures are still contaminated by thermally induced TP center of gravity (cg) zero-thrust baseline shifts brought on by the expansion of the copper frustum and aluminum RF amp and its heat sink when heated by the RF, even though these copper and aluminum cg shifts are now fighting each other. (Sadly these TP cg baseline shifts are ~3X larger in-vacuum than in-air due to the better insulating qualities of the vacuum, so the in-vacuum thrust runs look very thermally contaminated whereas the in-air run look very impulsive.) So we have now developed an analytical tool to help separate the EM-Drive thrust pulse waveform contributions from the thermal expansion cg induced baseline shifts of the TP. Not being satisfied with just this analytical impulsive vs thermal signal separation approach, we are now working on a new integrated test article subsystem mounting arrangement with a new phase-change thermal management subsystem that should mitigate this thermally induced TP cg baseline shift problem once and for-all.
And yet the anomalous thrust signals remain...
Best, Paul March
Paul,
That's wonderful news! I am super excited for you.
I do have a question, however. This is going to take a while to ask, so bare with me for a moment.
I started following this topic back during thread 2. Then sort of missed out on threads three and four. During thread 2, someone posted a paper published in the 1950's by A. L. Cullen who was studying the behavior of microwaves bouncing around within closed metal containers. He did this with containers of a constant profile, rather than ones of a varying profile such as those used in an EmDrive. However, he ran into the issue of the containers heating up and generating thermal lift. He solved this by placing a ring reflector on each end of his containers, as shown in fig. 12 on page 8 in his paper. The microwaves continued to bounce around within the container, but the issue of thermal lift was no longer a problem.
My question is this: In order to solve the thermal lift issue, why hasn't anyone attempted using ring reflectors on the ends of their EmDrives, as Cullen showed that was a viable solution, to this exact issue, without a need to use a vacuum chamber in the 1950's? -
#811 by Notsosureofit on 31 Oct, 2015 17:43
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Great Paul !
100microN, 80W, TM212, should only need Q ~ 12,000 to stay within "No new physics required"
Do you have a Q measurement you can share ?
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#812 by SeeShells on 31 Oct, 2015 17:44
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Paul,Doesn't anyone here have any reply at all to the substance of this paper? Just throwing out insults without providing any justification for the insults isn't very persuasive.
All:
And yet the anomalous thrust signals remain...
Best, Paul March
That's not only good news, but it is great news. Beautiful engineering work by your team, simply beautiful. I like the way you're systematically dialing out the other factors other then the anomalous thrust. Far better than I could do in my DTI. That said I can try to raise the anomalous thrust further out of the noise and prove that increased thrust gain is possible and add to the pool of data which I'm happy to do.
Shell -
#813 by meberbs on 31 Oct, 2015 18:28
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100microN, 80W, TM212, should only need Q ~ 12,000 to stay within "No new physics required"
Any thrust greater than 3.33 nano-Newtons per Watt would require new physics. I'm always hoping for new physics since it could revolutionize space travel, but unfortunately solid new physics results are pretty rare.
Paul March,
Some people on this thread have been having trouble accepting that the emDrive requires new physics to explain its thrust if it is not experimental error. Could you please clarify for them that explanations such as this page are accurate descriptions of electrodynamics, and something else (quantum vacuum, gravitational warping, dark matter, or other effects not recorded to date) would be required to explain any anomylous thrust? I think this would help discussion on the emDrive to be much more productive.
Thank you.
Also, I am glad you are making progress on eliminating sources of error. -
#814 by Star-Drive on 31 Oct, 2015 18:43
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Given all of the above TP wiring and test article modifications with respect to our 2014 AIAA/JPC paper design baseline needed to address these Lorentz force magnetic interaction issues, we are still seeing over 100uN of force with 80W of RF power going into the frustum running in the TM212 resonant mode, now in both directions, dependent on the direction of the mounted integrated test article on the TP. However these new plus and minus thrust signatures are still contaminated by thermally induced TP center of gravity (cg) zero-thrust baseline shifts brought on by the expansion of the copper frustum and aluminum RF amp and its heat sink when heated by the RF, even though these copper and aluminum cg shifts are now fighting each other. (Sadly these TP cg baseline shifts are ~3X larger in-vacuum than in-air due to the better insulating qualities of the vacuum, so the in-vacuum thrust runs look very thermally contaminated whereas the in-air run look very impulsive.) So we have now developed an analytical tool to help separate the EM-Drive thrust pulse waveform contributions from the thermal expansion cg induced baseline shifts of the TP. Not being satisfied with just this analytical impulsive vs thermal signal separation approach, we are now working on a new integrated test article subsystem mounting arrangement with a new phase-change thermal management subsystem that should mitigate this thermally induced TP cg baseline shift problem once and for-all.
And yet the anomalous thrust signals remain...
Best, Paul March
Paul,
That's wonderful news! I am super excited for you.
I do have a question, however. This is going to take a while to ask, so bare with me for a moment.
I started following this topic back during thread 2. Then sort of missed out on threads three and four. During thread 2, someone posted a paper published in the 1950's by A. L. Cullen who was studying the behavior of microwaves bouncing around within closed metal containers. He did this with containers of a constant profile, rather than ones of a varying profile such as those used in an EmDrive. However, he ran into the issue of the containers heating up and generating thermal lift. He solved this by placing a ring reflector on each end of his containers, as shown in fig. 12 on page 8 in his paper. The microwaves continued to bounce around within the container, but the issue of thermal lift was no longer a problem.
My question is this: In order to solve the thermal lift issue, why hasn't anyone attempted using ring reflectors on the ends of their EmDrives, as Cullen showed that was a viable solution, to this exact issue, without a need to use a vacuum chamber in the 1950's?
Corelock:
I believe that RFMWGuy tried a form of Cullen's porous reflector solution to mitigate the frustum thermal lift issue in-air when he built his frustum out of copper screen mesh. That solution mitigated some of the thermal lift in-air problems, at the price of a low Q-factor if memory serves. Dependent on the desired E&M resonant mode (TE or TM) to be excited, since TM modes require radial currents in the end-caps and longitudinal currents in the frustum walls, while the TE modes require circular currents in the end caps and side walls of the frustum, one should at least use the copper mesh with enough electrically bonded radial and longitudinal copper rods on the frustum walls for the TM modes and circular copper hoops on the end-caps and the frustum's slanted walls to minimize Q-factor losses while still allowing sufficient air to pass through needed to provide frustum cooling.
Best, Paul M. -
#815 by Notsosureofit on 31 Oct, 2015 18:46
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Any thrust greater than 3.33 nano-Newtons per Watt would require new physics. I'm always hoping for new physics since it could revolutionize space travel, but unfortunately solid new physics results are pretty rare.
Glad to see we agree in principle. Where is your calculation of 3.33 nano-Newtons per Watt ? -
#816 by flux_capacitor on 31 Oct, 2015 18:53
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Paul March,
Some people on this thread have been having trouble accepting that the emDrive requires new physics to explain its thrust if it is not experimental error. Could you please clarify for them that explanations such as this page are accurate descriptions of electrodynamics, and something else (quantum vacuum, gravitational warping, dark matter, or other effects not recorded to date) would be required to explain any anomylous thrust? I think this would help discussion on the emDrive to be much more productive.
Paul said in previous threads that Dr White, lead Eagleworks scientist, favors the Quantum Vacuum Fluctuation conjecture to explain the anomalous EmDrive thrust, implying virtual particles could be pushed on with Lorentz forces like a virtual magnetohydrodynamic drive (this is "new physics" in the sense that the accepted physics currently views the vacuum state as being immutable).
Also, Paul himself said several times here that he thinks the EmDrive thrust could originate from a Mach effect. I let you judge if this should be considered as "new physics" or more like some "upgraded old physics" as Mach's principle can be integrated into the "plain vanilla" general theory of relativity without referring to any quantum field like QVF. However, GRT with Mach's principle indeed requires an "action at a distance" field, a flavor of advanced/retarded waves of the Wheeler–Feynman absorber theory.
Personally I like this M-E theory more than QVF since it is CoM-savvy, as momentum transferred to the drive here is exchanged with the chiefly distant matter there (in the rest of the universe, through the gravinertial advanced/retarded Wheeler-Feynman field): CoM is preserved. Whereas with QFV, CoM seems broken since you are pushing off virtual particles that completely disappear after they have been pushed on. -
#817 by meberbs on 31 Oct, 2015 19:01
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Any thrust greater than 3.33 nano-Newtons per Watt would require new physics. I'm always hoping for new physics since it could revolutionize space travel, but unfortunately solid new physics results are pretty rare.
Glad to see we agree in principle. Where is your calculation of 3.33 nano-Newtons per Watt ?
That is just the efficiency of a photon rocket. I don't feel like typing Greek letters, so the derivation is here. (Note that calculation is for a mirror, so it has double the result.) -
#818 by Star-Drive on 31 Oct, 2015 19:07
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100microN, 80W, TM212, should only need Q ~ 12,000 to stay within "No new physics required"
Any thrust greater than 3.33 nano-Newtons per Watt would require new physics. I'm always hoping for new physics since it could revolutionize space travel, but unfortunately solid new physics results are pretty rare.
Paul March,
Some people on this thread have been having trouble accepting that the emDrive requires new physics to explain its thrust if it is not experimental error. Could you please clarify for them that explanations such as this page are accurate descriptions of electrodynamics, and something else (quantum vacuum, gravitational warping, dark matter, or other effects not recorded to date) would be required to explain any anomylous thrust? I think this would help discussion on the emDrive to be much more productive.
Thank you.
Also, I am glad you are making progress on eliminating sources of error.
Notsosureofit:
The integrated copper frustum test article's -3dB loaded Q-factor for the 80W / ~100uN test runs or 1.25 uN/W was 7,100. That is 1.25 uN/W / 3.33 nano-Newton (nN) / Watt = ~375.4 times as much thrust as a 100% efficient E&M rocket can produce.
Meberbs:
"Some people on this thread have been having trouble accepting that the emDrive requires new physics to explain its thrust if it is not experimental error."
I concur with your position that Maxwell's Classical E&M can NOT explain the frustum test results we continue to see, because when you sum up ALL of the Maxwellpressurestress tensors in the frustum due to all the E&M fields bouncing around inside the cavity and their interactions with any interior components like the PE discs and the active copper layer in the frustum's end and side walls, the NET force answer has to be ZERO by definition. In other words classical E&M cannot provide an explanation for conservation of momentum for a closed E&M system that produces a net thrust. -
#819 by SeeShells on 31 Oct, 2015 19:37
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If anyone feels like beating their head on the desk and run through this chapter to prove that Paul is right, be my guest. To save you knots, I'll give you a clue it's not there. https://archive.org/stream/ClassicalElectrodynamics/Jackson-ClassicalElectrodynamics#page/n253/mode/2up100microN, 80W, TM212, should only need Q ~ 12,000 to stay within "No new physics required"
Any thrust greater than 3.33 nano-Newtons per Watt would require new physics. I'm always hoping for new physics since it could revolutionize space travel, but unfortunately solid new physics results are pretty rare.
Paul March,
Some people on this thread have been having trouble accepting that the emDrive requires new physics to explain its thrust if it is not experimental error. Could you please clarify for them that explanations such as this page are accurate descriptions of electrodynamics, and something else (quantum vacuum, gravitational warping, dark matter, or other effects not recorded to date) would be required to explain any anomylous thrust? I think this would help discussion on the emDrive to be much more productive.
Thank you.
Also, I am glad you are making progress on eliminating sources of error.
Notsosureofit:
The integrated copper frustum test article's -3dB loaded Q-factor for the 80W / ~100uN test runs or 1.25 uN/W was 7,100. That is 1.25 uN/W / 3.33 nano-Newton (nN) / Watt = ~375.4 times as much thrust as a 100% efficient E&M rocket can produce.
Meberbs:
"Some people on this thread have been having trouble accepting that the emDrive requires new physics to explain its thrust if it is not experimental error."
I concur with your position that Maxwell's Classical E&M can NOT explain the frustum test results we continue to see, because when you sum up ALL of the Maxwell pressure tensors in the frustum due to all the E&M fields bouncing around inside the cavity and their interactions with any interior components like the PE discs and the active copper layer in the frustum's end and side walls, the NET force answer has to be ZERO by definition. In other words classical E&M cannot provide an explanation for conservation of momentum for a closed E&M system that produces a net thrust.
So, there seems to be a hole, for something we don't quite understand...yet.
We do have to get the heat out somehow, but with the new GaN components they get really efficient and until you get to 100s of W of rf power it's not going to be much of a concern.