Author Topic: EM Drive Developments - related to space flight applications - Thread 3  (Read 1799956 times)

Offline SeeShells

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See this article on a holey waveguide analysis with Meep:

http://ab-initio.mit.edu/wiki/index.php/Meep_Tutorial/Band_diagram,_resonant_modes,_and_transmission_in_a_holey_waveguide

If anybody attempts to model the bases with holes in Meep, please note that this would involve a greater number of FD nodes that at present in the circular cross-section, and therefore the number of FD nodes in the circular cross section would end up  being greater than in the longitudinal direction (unless those are also increased).  If the FD cell defined by a number of FD nodes is too distorted (a long rectangle instead of an ideal square, or worse a geometrical figure with very different inscribed angles) numerical issues ensue, so please look into acceptable Finite Difference mesh distortion before meshing and calculating.
I bow to your expertise in this. Whatcha need from the sleepless girl in the hot tub?

Offline SeeShells

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See this article on a holey waveguide analysis with Meep:

http://ab-initio.mit.edu/wiki/index.php/Meep_Tutorial/Band_diagram,_resonant_modes,_and_transmission_in_a_holey_waveguide

If anybody attempts to model the bases with holes in Meep, please note that this would involve a greater number of FD nodes that at present in the circular cross-section, and therefore the number of FD nodes in the circular cross section would end up  being greater than in the longitudinal direction (unless those are also increased).  If the FD cell defined by a number of FD nodes is too distorted (a long rectangle instead of an ideal square, or worse a geometrical figure with very different inscribed angles) numerical issues ensue, so please look into acceptable Finite Difference mesh distortion before meshing and calculating.
Why don't I think of something tougher? Just read the article.

I wonder how they model a dish with perforations? Off to dig.

Shell

Offline TheTraveller

Wonder what would happen if I arrived at SpaceX reception, with several working 1N/kW EMDrive complete systems in tow and asked to see Elon Musk?
"As for me, I am tormented with an everlasting itch for things remote. I love to sail forbidden seas.
Herman Melville, Moby Dick

Offline SeeShells

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Wonder what would happen if I arrived at SpaceX reception, with several working 1N/kW EMDrive complete systems in tow and asked to see Elon Musk?
I would recommend the EMDrives towing you.

Offline TheTraveller

Wonder what would happen if I arrived at SpaceX reception, with several working 1N/kW EMDrive complete systems in tow and asked to see Elon Musk?
I would recommend the EMDrives towing you.

Have already started discussions with SPR to explore license conditions to sell commercial 1N/kW complete (EMDrive + 1kW Rf amp + CMS) EMDrive systems. Customer will only needs to supply power and a few commands to the CMS.

And no I'm not jumping the gun. It is all doable.
"As for me, I am tormented with an everlasting itch for things remote. I love to sail forbidden seas.
Herman Melville, Moby Dick

Offline RotoSequence

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And no I'm not jumping the gun. It is all doable.

I admire your confidence, but even as a hopeful and optimistic observer, you're really counting your chickens before they've hatched.  :-\
« Last Edit: 07/15/2015 11:05 AM by RotoSequence »

Offline TheTraveller

And no I'm not jumping the gun. It is all doable.

I admire your confidence, but even as a hopeful and optimistic observer, you're really counting your chickens before they've hatched.  :-\

No not really. You see I have no doubt the EMDrive works as Shawyer claims. My plan just engages known knowledge plus engineer $s and hours to achieve a desired end result. I have committed $20k to the 1st and 2nd stages.

1) Build EMDrive, CMS and rotary table to demo continual acceleration. SPR did this back in 2006 but their table could only turn a few revs due to cords. My table can turn an unlimited number of turns as it is cordless.

2) Build and distribute 7 x 100W EMDrive complete systems to Force verifiers.

Then commercial production of a 1kW Rf amp powered 1N/kW EMDrive becomes interesting. This system may be 2.45GHz or 5.8GHz or even 24GHz. Depends on test data.

This is like building a conventional Sterling Engine and Generator combo but this Sterling Engine doesn't need any heat input to generate output energy to turn the Generator.
« Last Edit: 07/15/2015 11:28 AM by TheTraveller »
"As for me, I am tormented with an everlasting itch for things remote. I love to sail forbidden seas.
Herman Melville, Moby Dick

Offline ElizabethGreene

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This is like building a conventional Sterling Engine and Generator combo but this Sterling Engine doesn't need any heat input to generate output energy to turn the Generator.

Tangent question:  Is there an off-the shelf source for a (preferably inexpensive) Sterling engine/generator combo?  I saw a kickstarter for one a few years ago but that's it.

I choose to ignore the high-quality perpetual motion machine bait. :)

Offline TheTraveller

This is like building a conventional Sterling Engine and Generator combo but this Sterling Engine doesn't need any heat input to generate output energy to turn the Generator.

Tangent question:  Is there an off-the shelf source for a (preferably inexpensive) Sterling engine/generator combo?  I saw a kickstarter for one a few years ago but that's it.

I choose to ignore the high-quality perpetual motion machine bait. :)

Not that I'm aware of but I haven't followed Sterling development / availability for a year or so.

Suspect problem is self limiting. No / little volume = high prices and limited availability.
« Last Edit: 07/15/2015 12:06 PM by TheTraveller »
"As for me, I am tormented with an everlasting itch for things remote. I love to sail forbidden seas.
Herman Melville, Moby Dick

Offline teitur

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This is like building a conventional Sterling Engine and Generator combo but this Sterling Engine doesn't need any heat input to generate output energy to turn the Generator.

Tangent question:  Is there an off-the shelf source for a (preferably inexpensive) Sterling engine/generator combo?  I saw a kickstarter for one a few years ago but that's it.

I choose to ignore the high-quality perpetual motion machine bait. :)

A friend of mine has one which is like a child's toy. You might find one in the toy store :)

Offline rfcavity

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And no I'm not jumping the gun. It is all doable.

I admire your confidence, but even as a hopeful and optimistic observer, you're really counting your chickens before they've hatched.  :-\

No not really. You see I have no doubt the EMDrive works as Shawyer claims. My plan just engages known knowledge plus engineer $s and hours to achieve a desired end result. I have committed $20k to the 1st and 2nd stages.

1) Build EMDrive, CMS and rotary table to demo continual acceleration. SPR did this back in 2006 but their table could only turn a few revs due to cords. My table can turn an unlimited number of turns as it is cordless.

2) Build and distribute 7 x 100W EMDrive complete systems to Force verifiers.

Then commercial production of a 1kW Rf amp powered 1N/kW EMDrive becomes interesting. This system may be 2.45GHz or 5.8GHz or even 24GHz. Depends on test data.

This is like building a conventional Sterling Engine and Generator combo but this Sterling Engine doesn't need any heat input to generate output energy to turn the Generator.
A 1kW RF amp that doesn't put any heat into the system... I wish! You could make a lot of money on just that alone if it were true.

Offline TheTraveller

A 1kW RF amp that doesn't put any heat into the system... I wish! You could make a lot of money on just that alone if it were true.

When did I say that?

In space apps, almost all the waste heat will be from the Rf amps.

As in this picture, space based EMDrives will need significant heat radiators to deal with their Rf amps waste heat output.
« Last Edit: 07/15/2015 01:33 PM by TheTraveller »
"As for me, I am tormented with an everlasting itch for things remote. I love to sail forbidden seas.
Herman Melville, Moby Dick

Offline wallofwolfstreet

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Todd

Todd,

Any EMDrive theory must show the direction of the dielectric generated Force (Small to Big) at 180 deg opposite the non dielectric case (Big to Small) and the dielectric Force to be much weaker than the non dielectric case.

Can your theory do that?

Traveller, is it true that a tapered waveguide with a dielectric insert in the small end will thrust towards the big end, and that the same tapered waveguide without the dielectric will thrust toward the small end?  Do I have that right?

With that in mind, how does Shawyer's variable group velocity ==> variable radiation pressure theory explain this flipping thrust direction? 

Offline SeeShells

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Momentum, spin, force, acceleration, mass, magnetic, electric forces of light, light is even a particle and a wave that exhibits quantum effects (slit experiment) and spooky actions of entanglement with superluminal instantaneous actions across long distances, evanescent waves like a stripped down version of a wave that can impart first order forces and control the movement of small particles. All of these forces and actions are carried in a wave. I keep remembering Einstein's equation E=MC2 and remind myself that light (energy) is simply a form of the forces that make matter what it is. If there is a formula for controlling mass and acceleration and warping spacetime like matter does it is in the waves (energy) on the other side of the equation. Making all this work like it does is the Quantum Vacuum of space-time.
There are about 12 theories out there and each has pluses and minuses understanding how the fundamental makeup of light (RF shoved into in the EMDrive) can be modified to give us an effect that takes us places with out thrust. We really are not violating anything but using what mother nature gave us in E=MC2.

So why is light massless?

Einstein's special relativity says E2=p2c2+m2c4 and if E=pc, then we're all okay (? Ha) with zero mass... nonvanishing energy and momentum... my head spins.

My hat is off to you here who can find the Betty Crocker ingredients in a photon to rip and cajole out mass and momentum.

Shell

Note to self. quit playing physics. Because some neutrinos are not massless.

Another note: What Betty Crocker mix makes some neutrinos show mass and some not?

Final note and mod: Nobody need to answer this because the answers are online. I just had a dream this morning I was in the kitchen (I do go there) with a beater made of EM microwaves stirring a bowl shaped like a EMDrive, weird huh? I think I'll go sit in the hot tub.
« Last Edit: 07/15/2015 03:18 PM by SeeShells »

Offline leomillert

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How to help scientists gather data and study the EMDrive, even if you are an absolute novice.

If you are excited about the EMDrive and wants to contribute to its research, but don't know how, this is a step-by-step guide that if performed correctly by anyone out there interested in helping would provide valuable information for the scientists to study and better understand the EMDrive behavior.

1. Install MEEP http://ab-initio.mit.edu/wiki/index.php/Meep (preferably from your package manager)
2. Download https://forum.nasaspaceflight.com/index.php?action=dlattach;topic=37642.0;attach=1042821 and rename it to NSF-1701.ctl
3. meep NSF-1701.ctl
4. Eventually, MEEP will output nine .h5 files. It may take a long time depending on your computer. Patience is a virtue.
5. h5totxt -t 13 -0 -y -0  ex.h5 > zCopper-exy.csv
6. Open your zCopper-exy.csv on a spread sheet and aero's zCopper-exy.csv on another. Open a third spread sheet that is one spread sheet minus the other, entry by entry. Check that highest entry (in absolute value). If it's negligible you are good to go. If it's a value too big, greater than 10^-6, your MEEP installation isn't in sync with ours, so it's no use.
7. Now you are good to go. Make a new directory to start the tests. Copy NSF-1701.ctl there.
8. Open NSF-1701.ctl in a text editor and change a single value. For example, (set! high 10.2) means the model is 10.2 inches high. Change the 10.2 to another value and save NSF-1701.ctl with this single change. This is called sensitivity analysis. One value at a time. (set! high 10.2) was just an example, change any value of interest
9. meep NSF-1701.ctl
10. h5totxt -t 13 -0 -y -0  ex.h5 > zCopper-exy.csv
11. Compare your new zCopper-exy.csv with your old one. See if there was any relevant change (do the spreadsheet comparison again). If there was no considerable change in values, it means the modification made doesn't impact the behavior of the EMDrive. This is an important information for scientists, so let us know. Otherwise, if there was a significant change, let us know if it was positive or negative and its intensity. If you don't know how, just upload the .h5 files somewhere and we will analyze it.

« Last Edit: 07/15/2015 04:47 PM by leomillert »

Offline Rodal

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Continued from here:  http://forum.nasaspaceflight.com/index.php?topic=37642.msg1404893#msg1404893

Dissipation leads to decay of a wave form.  Dispersion leads to gradual separation of wave patterns into a train of oscillations This depends upon constructive and destructive interference of Fourier components.  Although many partial differential equations are nondispersive their Finite Difference approximations are almost invariably dispersive. Phase and group velocity analysis depend upon the problem being linear and nondissipative.  Thus this problem (EM Drive truncated cone with RF feed ON) is not as trivial as R. Shawyer makes it to be nor as its detractors make it to be.   The whole discussion about "phase vs. group velocity" is too simplistic for a truncated cone with the RF feed ON.
   

In a numerical scheme like Finite Differences (used by Meep) group velocity has more physical meaning than phase velocity.   On a periodic grid any Fourier mode can be represented in terms of infinitely many possible choices of  frequency and wavevector that are indistinguishable physically.   Each choice gives a different phase velocity.

One cannot tell how fast a pure complex exponential wave is moving if one sees it at only intermittent points in space or time for one wave crest is indistinguishable from another. By contrast the group velocity is well defined since it depends only on the slope which is a local property formula.

But if the problem entails dissipation as well dispersion, the discussion about phase vs. group velocity (and what they mean) approaches being moot, since such confining discussion would ignore the dissipation aspect of the problem.

« Last Edit: 07/15/2015 03:32 PM by Rodal »

Offline rfmwguy

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Momentum, spin, force, acceleration, mass, magnetic, electric forces of light, light is even a particle and a wave that exhibits quantum effects (slit experiment) and spooky actions of entanglement with superluminal instantaneous actions across long distances, evanescent waves like a stripped down version of a wave that can impart first order forces and control the movement of small particles. All of these forces and actions are carried in a wave. I keep remembering Einstein's equation E=MC2 and remind myself that light (energy) is simply a form of the forces that make matter what it is. If there is a formula for controlling mass and acceleration and warping spacetime like matter does it is in the waves (energy) on the other side of the equation. Making all this work like it does is the Quantum Vacuum of space-time.
There are about 12 theories out there and each has pluses and minuses understanding how the fundamental makeup of light (RF shoved into in the EMDrive) can be modified to give us an effect that takes us places with out thrust. We really are not violating anything but using what mother nature gave us in E=MC2.

So why is light massless?

Einstein's special relativity says E2=p2c2+m2c4 and if E=pc, then we're all okay (? Ha) with zero mass... nonvanishing energy and momentum... my head spins.

My hat is off to you here who can find the Betty Crocker ingredients in a photon to rip and cajole out mass and momentum.

Shell

Note to self. quit playing physics. Because some neutrinos are not massless.

Another note: What Betty Crocker mix makes some neutrinos show mass and some not?
Before particles began to mix things up, photonic energy was considered ripples in space-time itself...simply a resonance of the fabric so to speak. A ripple on the ocean contains only the ocean; a massless force that created the ripple.

So then came particles and the assumption of mass.

Offline SeeShells

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Momentum, spin, force, acceleration, mass, magnetic, electric forces of light, light is even a particle and a wave that exhibits quantum effects (slit experiment) and spooky actions of entanglement with superluminal instantaneous actions across long distances, evanescent waves like a stripped down version of a wave that can impart first order forces and control the movement of small particles. All of these forces and actions are carried in a wave. I keep remembering Einstein's equation E=MC2 and remind myself that light (energy) is simply a form of the forces that make matter what it is. If there is a formula for controlling mass and acceleration and warping spacetime like matter does it is in the waves (energy) on the other side of the equation. Making all this work like it does is the Quantum Vacuum of space-time.
There are about 12 theories out there and each has pluses and minuses understanding how the fundamental makeup of light (RF shoved into in the EMDrive) can be modified to give us an effect that takes us places with out thrust. We really are not violating anything but using what mother nature gave us in E=MC2.

So why is light massless?

Einstein's special relativity says E2=p2c2+m2c4 and if E=pc, then we're all okay (? Ha) with zero mass... nonvanishing energy and momentum... my head spins.

My hat is off to you here who can find the Betty Crocker ingredients in a photon to rip and cajole out mass and momentum.

Shell

Note to self. quit playing physics. Because some neutrinos are not massless.

Another note: What Betty Crocker mix makes some neutrinos show mass and some not?
Before particles began to mix things up, photonic energy was considered ripples in space-time itself...simply a resonance of the fabric so to speak. A ripple on the ocean contains only the ocean; a massless force that created the ripple.

So then came particles and the assumption of mass.
I know. The let there be light was a biggie but let there be mass is where we are now. I have on my bookshelf A brief history of time and The universe in a nutshell, I'll take out and re-read just to see a complex universe shown simply, that in itself is beautiful.

Offline TheTraveller

Todd

Todd,

Any EMDrive theory must show the direction of the dielectric generated Force (Small to Big) at 180 deg opposite the non dielectric case (Big to Small) and the dielectric Force to be much weaker than the non dielectric case.

Can your theory do that?

Traveller, is it true that a tapered waveguide with a dielectric insert in the small end will thrust towards the big end, and that the same tapered waveguide without the dielectric will thrust toward the small end?  Do I have that right?

With that in mind, how does Shawyer's variable group velocity ==> variable radiation pressure theory explain this flipping thrust direction?

The flipped Force direction is correct as per published experimental data from 4 experimenters as attached

As far as I know, Shawyer never addressed the dielectric results in his theory, other than in the 2 relevant UK patents attached.

So the field is wide open for you and others to have a go. Good luck.

BTW your claimed that Shawyer's claim that variable group velocity (variable Guide Wavelength) generates variable radiation Force is a theory is not correct. Cullen 15 (attached) and waveguide physics proves it is correct.

If you don't understand that please check out how Group Velocity and Group Wavelength are related Vg = c * (Lambda0 / Lambdag) Lambdag is the Guide Wavelength and it changes as the tapered waveguide diameter changes as the EM wave passes along the tapered waveguide.
"As for me, I am tormented with an everlasting itch for things remote. I love to sail forbidden seas.
Herman Melville, Moby Dick

Offline TheTraveller

Continued from here:  http://forum.nasaspaceflight.com/index.php?topic=37642.msg1404893#msg1404893

Dissipation leads to decay of a wave form.  Dispersion leads to gradual separation of wave patterns into a train of oscillations This depends upon constructive and destructive interference of Fourier components.  Although many partial differential equations are nondispersive their Finite Difference approximations are almost invariably dispersive. Phase and group velocity analysis depend upon the problem being linear and nondissipative.  Thus this problem (EM Drive truncated cone with RF feed ON) is not as trivial as R. Shawyer makes it to be nor as its detractors make it to be.   The whole discussion about "phase vs. group velocity" is too simplistic for a truncated cone with the RF feed ON.
   

In a numerical scheme like Finite Differences (used by Meep) group velocity has more physical meaning than phase velocity.   On a periodic grid any Fourier mode can be represented in terms of infinitely many possible choices of  frequency and wavevector that are indistinguishable physically.   Each choice gives a different phase velocity.

One cannot tell how fast a pure complex exponential wave is moving if one sees it at only intermittent points in space or time for one wave crest is indistinguishable from another. By contrast the group velocity is well defined since it depends only on the slope which is a local property formula.

But if the problem entails dissipation as well dispersion, the discussion about phase vs. group velocity (and what they mean) approaches being moot, since such confining discussion would ignore the dissipation aspect of the problem.

Here is the simple bit.

In a waveguide Group Velocity is below c and is the speed that info, energy and momentum travels inside a waveguide. Phase Velocity, inside a waveguide, is above c. Nothing travels at Phase Velocity inside a waveguide.

So learn to deal with variable Group Velocity (Guide Wavelength), driven by waveguide diameter changes, being the velocity that information, energy and momentum travels inside a waveguide or go up against waveguide physics and reality.

Cullen is correct. Shawyer is correct. Prof Yang is correct.

Your theory that Group Velocity is not the velocity of momentum inside a waveguide and that the Group Velocity doesn't vary with diameter change is not correct.
« Last Edit: 07/15/2015 03:44 PM by TheTraveller »
"As for me, I am tormented with an everlasting itch for things remote. I love to sail forbidden seas.
Herman Melville, Moby Dick

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