### Author Topic: EM Drive Developments - related to space flight applications - Thread 2  (Read 2603197 times)

#### Rodal

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##### Re: EM Drive Developments - related to space flight applications - Thread 2
« Reply #1660 on: 04/06/2015 01:10 pm »
Modeling a plane wave striking an absorbing surface is a different problem than modeling the standing waves in a resonating cavity like the EM Drive.

I was referring to images like these ones, that you posted some time ago:

The electromagnetic fields in that image don't look like the electromagnetic fields in the EM Drive, indicating that there was something wrong with your model of the EM Drive.  Since electromagnetic forces are due to the electromagnetic fields, if one doesn't get the electromagnetic fields correctly, then it stands to reason that the calculations of electromagnetic forces in the EM Drive cannot be correct either.

Wasn't that particular simulation modeling the EM Drive without openings, which in turn showed us how important the openings are to the overall operation of the drive (at least in the simulation)?
If a numerical model cannot get the electromagnetic fields correctly for the EM Drive in that simpler case, one cannot derive from such a model valid conclusions on the importance of "the openings are to the overall operation of the drive" or to the validity of forces that are based on derivatives of the fields.

One should not extrapolate that a two-dimensional (2D) model of the EM Drive that ignores its circular cross-section and three-dimensional field effects can be used to show valid conclusions on the importance of "the openings are to the overall operation of the drive" of the physical three-dimensional (3D) EM Drive.

A flat 2D model like this one, completely ignores for example the main electromagnetic field in the TM (transverse magnetic) 212 mode presently being tested by NASA Eagleworks.  The transverse magnetic field occurs out of the plane shown in the figure, in the azimuthal direction and it has 2 full wave patterns in that circumferential direction.  None of this is being modeled by this 2D Finite Difference simulation.

« Last Edit: 04/06/2015 02:20 pm by Rodal »

#### Rodal

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##### Re: EM Drive Developments - related to space flight applications - Thread 2
« Reply #1661 on: 04/06/2015 01:58 pm »
Modeling a plane wave striking an absorbing surface is a different problem than modeling the standing waves in a resonating cavity like the EM Drive.

I was referring to images like these ones, that you posted some time ago:

The electromagnetic fields in that image don't look like the electromagnetic fields in the EM Drive, indicating that there was something wrong with your model of the EM Drive.  Since electromagnetic forces are due to the electromagnetic fields, if one doesn't get the electromagnetic fields correctly, then it stands to reason that the calculations of electromagnetic forces in the EM Drive cannot be correct either.

Wasn't that particular simulation modeling the EM Drive without openings, which in turn showed us how important the openings are to the overall operation of the drive (at least in the simulation)?
If a numerical model cannot get the electromagnetic fields correctly for the EM Drive in that simpler case, one cannot derive from such a model valid conclusions on the importance of "the openings are to the overall operation of the drive" or to the validity of forces that are based on derivatives of the fields.

One should not extrapolate that a two-dimensional (2D) model of the EM Drive that ignores its circular cross-section and three-dimensional field effects can be used to show valid conclusions on the importance of "the openings are to the overall operation of the drive" of the physical three-dimensional (3D) EM Drive.

A flat 2D model like this one, completely ignores for example the main electromagnetic field in the TM (transverse magnetic) 212 mode presently being tested by NASA Eagleworks.  The transverse magnetic field occurs out of the plane shown in the figure, in the azimuthal direction and it has 2 full wave patterns in that circumferential direction.  None of this is being modeled by this 2D Finite Difference simulation.
I had asked (at a time that I didn't know that this was a 2D instead of a 3D model) whether the figure represented a component of (or the norm of) the electric or the magnetic field.

Do you have an intuition for what this 2D model represents?  For cyl. transverse magnetic (TM) modes the magnetic field is a directionless scalar.  For cyl. transverse electric (TE) modes the electric field is a directionless scalar.

In such a two dimensional model, where the magnetic field component direction and variation in the circumferential (azimuthal) direction is completely ignored,  what do you have for the magnetic fields?  The magnetic fields become just a scalar, the magnetic field is not longer a vector.

In the real 3D EM Drive cavity the standing waves are such that the electric and magnetic fields are out of phase by 90 degrees, and therefore the energy is transferred from the electric field to the magnetic field back and forth.  What happens in this 2D model? The electric field energy from the electric vector field gets transferred into a scalar magnetic field ?

In 3D we have dot products and cross products. With a scalar magnetic field in 2D, there's no curl or divergence. We only have a gradient.  The "curl" of the electric field is a scalar in such a model.

The equation that says magnetic field lines form closed loops which never begin or end- the divergence of the magnetic field is always zero - (http://farside.ph.utexas.edu/teaching/302l/lectures/node78.html) vanishes. Hence magnetic monopoles exist in this 2D electromagnetic Flatland?

Can you show how the magnetic scalar field in this 2D model relates to the transverse magnetic field in the cyl. TM212 mode being tested at NASA?

How do the "two-dimensional forces" in such a 2D flatland relate to our 3D problem?

Some good-nature humor to make us think about the differences between flatland and our 3D space  :

« Last Edit: 04/06/2015 03:39 pm by Rodal »

#### aceshigh

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##### Re: EM Drive Developments - related to space flight applications - Thread 2
« Reply #1662 on: 04/06/2015 02:50 pm »
What QuantumG said. I'm sorry for being part of the digression. Let's focus on the EmDrive and its space-related flight applications.

not sure it was a digression, while itīs related on how to power EMDrive in spaceflight related applications.

itīs just like VASIMR thread... the power source is an important part of the thread.

but I agree that itīs futile to discuss it, itīs putting the cart in front of the horse (or a better analogy... cart is spaceship, horse is EM Drive and the carrot is the power source.)

#### spacenut

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##### Re: EM Drive Developments - related to space flight applications - Thread 2
« Reply #1663 on: 04/06/2015 04:09 pm »
Wouldn't argon be a better fuel for large EM drives, like for transfers to Mars with a lot of tonnage of equipment?  Say an in space only craft that would transfer cargo to Mars flyby, let the cargo have a chemical powered craft that would land equipment and the EM craft flys back to Earth say to L1 OR L2 to pick up more cargo?  Xenon is rare in comparison to argon.  If the craft were large enough, it could refuel at L1 with argon plus pick up or return a Mars cargo lander.  If the transfer time was fast enough, humans could also be transferred.

All that being said, with todays technology, how large would the solar panels be to say transfer 100 tons of cargo to and from Mars?  Would it be better to go chemical all the way?

#### aero

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##### Re: EM Drive Developments - related to space flight applications - Thread 2
« Reply #1664 on: 04/06/2015 04:42 pm »
@Rodal -
Are you telling me that an effect that shows in 2D  may not show in 3D, or that an effect that exists in 3D may not show in 2D? Or both?

I would prefer to have solutions in 3D myself, but I'm not going to get them with this computer system, the meep EM thruster cavity model is to large. Its not only long run times, but also memory requirements and even hard disk storage. I had one run bomb out because I ran out of disk space while writing the output files at the end of the run.

I am forced to operate on the hope and expectation that I will be able to confirm an effect that shows in 2D by making a 3D run targeted to that effect. If I can't do that, then I can't, but I certainly can not explore the parameter space by making 3D runs.
Retired, working interesting problems

#### Left Field

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##### Re: EM Drive Developments - related to space flight applications - Thread 2
« Reply #1665 on: 04/06/2015 04:49 pm »
Wouldn't argon be a better fuel for large EM drives, like for transfers to Mars with a lot of tonnage of equipment?  Say an in space only craft that would transfer cargo to Mars flyby, let the cargo have a chemical powered craft that would land equipment and the EM craft flys back to Earth say to L1 OR L2 to pick up more cargo?  Xenon is rare in comparison to argon.  If the craft were large enough, it could refuel at L1 with argon plus pick up or return a Mars cargo lander.  If the transfer time was fast enough, humans could also be transferred.

All that being said, with todays technology, how large would the solar panels be to say transfer 100 tons of cargo to and from Mars?  Would it be better to go chemical all the way?

The point of this EmDrive is that it does not require a reaction mass, so no xenon nor any other gas would be used. In short, it is not an ion or a magnetoplasma drive. If you would like to learn more then here is the wiki page for starters:

http://en.wikipedia.org/wiki/EmDrive

#### seggybop

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##### Re: EM Drive Developments - related to space flight applications - Thread 2
« Reply #1666 on: 04/06/2015 04:57 pm »
I would prefer to have solutions in 3D myself, but I'm not going to get them with this computer system, the meep EM thruster cavity model is to large. Its not only long run times, but also memory requirements and even hard disk storage. I had one run bomb out because I ran out of disk space while writing the output files at the end of the run

I'm familiar with these 2D vs 3D issues and I agree 3D is necessary.
I or others here with access to more substantial hardware can probably run said simulations for you, provided you can package up the software for us.

#### birchoff

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##### Re: EM Drive Developments - related to space flight applications - Thread 2
« Reply #1667 on: 04/06/2015 04:59 pm »
Aces High:

The hot fusion candidates you mentioned all have one major problem.  That being that except for D-T fusion, no hot fusion scheme to date has ever demonstrated breakeven let alone enough energy gain over its input to make it a viable aerospace fusion reactor candidate.  (I believe that the UK D-T fusion reactor may have reached breakeven for a few minute run, but Lord, look at the neutron flux it generates, which is ~70% of a pure fission reactor for a given output power, a pure fission reactor that can be much smaller and lighter than any tokomak reactor can ever be.)  And after seeing what happened during the poly-well fusion reactor saga, I have great doubts as to the claims by any of the current crop of alternate fusion reactor concepts, L-M's optimistic claims about their fusion reactor design concept not withstanding.

Best, Paul M.

You're mentioning the Joint European Torus (JET) tokamak. But there are other possible paths for controlled fusion other than tokamaks. Besides Polywell and Lockheed-Martin reactors you've just cited, maybe another scheme could reach breakeven "soon" among the aneutronic p-B11 Dense Plasma Focus fusion from LPP, the (also aneutronic) Colliding Beam Fusion Reactor from Tri Alpha Energy, the colliding FRC Fusion Engine from Helion Energy, the MTF compressor from General Fusion, the MagLIF z-pinch from Sandia National Labs… None of them are based on tokamaks. Whatever, finding an appropriate energy source for the spaceship before proving the EmDrive does work is an interesting thought experiment (and perhaps mandatory for management) but it is a bit putting the cart before the horse in my opinion.

Does anyone actually believe that if we had a working EmDrive with the predicted thrust capabilities that we would have a problem finding power for it?

From my perspective if we have a EmDrive with the predicted performance that Paul mentioned. Then I see the following happening.

1. Develop a hybrid power system that leverages existing fuelcell technology and solar cells. This opens up exploration and permanent bases on the moon, cis-lunar mars and venus. Hell if we can increase the efficiency even more then we could potentially get permanent access to the asteroid belt.

2. Once the commercial side effects of space expansion have taken root. There i no way in this universe that anyone will be able to prevent nuclear technology in whatever form it is economically available from being used in the 2nd generation ships. At that point we should have the power needed to explore our solar system and start sending "Fast" probes to our nearest neighbors.

Hell if the Emdrive provided the ability to do lift off from earth for the right amount of energy in. I could see a variant of the space elevator idea being built. Where we beam via lasers or microwaves the energy needed to feed the EmDrives till they get to Space with their cargo. They would then dock and offload cargo and passengers.

So from where I am standing, power will not be an issue if the EmDrive is proven to deliver usable thrust. We as a species will find a way.
« Last Edit: 04/06/2015 05:04 pm by birchoff »

#### Rodal

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##### Re: EM Drive Developments - related to space flight applications - Thread 2
« Reply #1668 on: 04/06/2015 05:30 pm »
@Rodal -
Are you telling me that an effect that shows in 2D  may not show in 3D, or that an effect that exists in 3D may not show in 2D? Or both?

I would prefer to have solutions in 3D myself, but I'm not going to get them with this computer system, the meep EM thruster cavity model is to large. Its not only long run times, but also memory requirements and even hard disk storage. I had one run bomb out because I ran out of disk space while writing the output files at the end of the run.

I am forced to operate on the hope and expectation that I will be able to confirm an effect that shows in 2D by making a 3D run targeted to that effect. If I can't do that, then I can't, but I certainly can not explore the parameter space by making 3D runs.
The general answer to the first question is: "both".

For an example of a non-physical effect found in a flat 2D model, I gave the example that the 2D flat Maxwell model allows for magnetic monopoles which are not allowed in 3D Maxwell's equations.  The equation that says magnetic field lines form closed loops which never begin or end- the divergence of the magnetic field is always zero - (http://farside.ph.utexas.edu/teaching/302l/lectures/node78.html) vanishes in the flat 2D model.  Just as one cannot conclude, based on a 2D model that magnetic monopoles exist in our world, one should be similarly careful about the conclusions of a flat 2D model for a real EM Drive.

For an example of a physical effect in 3D that will not show in a 2D flat model, all we have to do is consider the mode presently tested by NASA Eagleworks: cyl. TM212.  The flat 2D model not only fails to model the loop that the magnetic field makes in the circumferential (azimuthal) direction but the 2D model cannot model the variation of the magnetic field in that direction (it cannot model for cyl. TM212 the harmonic motion shape of the magnetic field in the azimuthal direction).

This will affect the calculation of the momentum of the evanescent waves, and therefore affect the calculation of the force.

I was responding to @sghill, and warning other readers of the thread that may not be aware of the flat nature of your numerical model about the issues involved with a "flat" two dimensional numerical model and therefore not to jump to conclusions based on flat 2D model.
« Last Edit: 04/06/2015 06:02 pm by Rodal »

#### tchernik

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##### Re: EM Drive Developments - related to space flight applications - Thread 2
« Reply #1669 on: 04/06/2015 06:04 pm »
Does anyone actually believe that if we had a working EmDrive with the predicted thrust capabilities that we would have a problem finding power for it?

....

So from where I am standing, power will not be an issue if the EmDrive is proven to deliver usable thrust. We as a species will find a way.

I fully agree. Fretting about the energy source is a bit too much at this stage, when conclusively proving the existence of the phenomenon has yet to happen.

If this becomes a proven scientific fact, with a few more conclusive replications, finding a power source for it is just an engineering problem. That is, one based on the application of already known scientific and technical principles. We know nukes work and we have them, we know fuel cells work and we have them, the same as solar photovoltaics, etc.

Gee, if Emdrives are proven to work as H. White and Paul M. expect, we would be soon putting gasoil engines/generators to power them, and this for replacing turbofans/propellers for flying in the low atmosphere!
« Last Edit: 04/06/2015 06:05 pm by tchernik »

#### Star One

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##### Re: EM Drive Developments - related to space flight applications - Thread 2
« Reply #1670 on: 04/06/2015 06:55 pm »
Does anyone actually believe that if we had a working EmDrive with the predicted thrust capabilities that we would have a problem finding power for it?

....

So from where I am standing, power will not be an issue if the EmDrive is proven to deliver usable thrust. We as a species will find a way.

I fully agree. Fretting about the energy source is a bit too much at this stage, when conclusively proving the existence of the phenomenon has yet to happen.

If this becomes a proven scientific fact, with a few more conclusive replications, finding a power source for it is just an engineering problem. That is, one based on the application of already known scientific and technical principles. We know nukes work and we have them, we know fuel cells work and we have them, the same as solar photovoltaics, etc.

Gee, if Emdrives are proven to work as H. White and Paul M. expect, we would be soon putting gasoil engines/generators to power them, and this for replacing turbofans/propellers for flying in the low atmosphere!

I believe because of their extremely contentious nature & reputation to the majority in the scientific community it's not just a case of showing EM drives work but producing a rock solid case for why they work. Unfortunately there has been so many other claims of a similar nature that have been made over the years that have proved to be nonsense that it has severely muddied the waters leaving things such as the EM drive with incredibly high hurdles to clear before anyone gives them the time of day.
« Last Edit: 04/06/2015 06:59 pm by Star One »

#### Rodal

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##### Re: EM Drive Developments - related to space flight applications - Thread 2
« Reply #1671 on: 04/06/2015 06:56 pm »
I would prefer to have solutions in 3D myself, but I'm not going to get them with this computer system, the meep EM thruster cavity model is to large. Its not only long run times, but also memory requirements and even hard disk storage. I had one run bomb out because I ran out of disk space while writing the output files at the end of the run

I'm familiar with these 2D vs 3D issues and I agree 3D is necessary.
I or others here with access to more substantial hardware can probably run said simulations for you, provided you can package up the software for us.
Even in the 2D flat model the finite difference mesh is coarse enough that one can see a fractal nature of the solution in these images:

compare this fractal looking images of the finite difference solution model with the continuous, much smoother solution provided by the COMSOL Finite Element solution:

The fractal nature of the electromagnetic fields inside the EM Drive look wrong.

This fractal nature is an artifact of the finite difference mesh discretization.  The electromagnetic fields are known to be continuous and not fractal.  The forces due to evanescent waves are primarily due to the gradient of the electromagnetic fields.   Due to the discontinuous fractal nature of the finite difference discretization coarse mesh, the gradient of the electromagnetic fields, and therefore the computed force is going to be significantly more inaccurate.  A 3D finite difference model would encounter severe mesh discretization issues.

If there are problems modeling the standing waves in the EM Drive by this finite difference model, just imagine the challenge to model evanescent waves with the numerical solution method. The evanescent wave is a small-scale feature which rapidly decays away from a material interface.

To compute the force, one needs to compute the gradient of the electromagnetic field.  Due to the exponential nature of the decay, significant numerical errors may occur when calculating the gradient, and hence when calculating the force.

It can be shown that the decay in the direction perpendicular to the interface is exponential and thus can lead to a very high gradient of the evanescent wave solution in that direction. In the direction along the interface, the evanescent solution oscillates.

Thus, capturing in a numerical computation the evanescent wave may require a fine mesh along the interface, even when the wave number is low enough that a coarser mesh suffices for other purposes.
« Last Edit: 04/06/2015 08:35 pm by Rodal »

#### birchoff

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##### Re: EM Drive Developments - related to space flight applications - Thread 2
« Reply #1672 on: 04/06/2015 08:35 pm »
Does anyone actually believe that if we had a working EmDrive with the predicted thrust capabilities that we would have a problem finding power for it?

....

So from where I am standing, power will not be an issue if the EmDrive is proven to deliver usable thrust. We as a species will find a way.

I fully agree. Fretting about the energy source is a bit too much at this stage, when conclusively proving the existence of the phenomenon has yet to happen.

If this becomes a proven scientific fact, with a few more conclusive replications, finding a power source for it is just an engineering problem. That is, one based on the application of already known scientific and technical principles. We know nukes work and we have them, we know fuel cells work and we have them, the same as solar photovoltaics, etc.

Gee, if Emdrives are proven to work as H. White and Paul M. expect, we would be soon putting gasoil engines/generators to power them, and this for replacing turbofans/propellers for flying in the low atmosphere!

I believe because of their extremely contentious nature & reputation to the majority in the scientific community it's not just a case of showing EM drives work but producing a rock solid case for why they work. Unfortunately there has been so many other claims of a similar nature that have been made over the years that have proved to be nonsense that it has severely muddied the waters leaving things such as the EM drive with incredibly high hurdles to clear before anyone gives them the time of day.

I somewhat agree with you. Mainly because I do not believe that a proven (not necessarily accepted) theory of how EmDrive's work is a show stopper. If someone gave us a blackbox space rated emdrive thruster were all we had to do was plug it in to an electrical energy source. I doubt any lay person or physicist would doubt that the drive works. Which means that the only reason we need an accepted theory is because it will increase the availability of funding. That said, if Eagleworks builds a replication kit that works every time I would argue that you can get the same increase in funding availability. So there are two avenues one can pursue; one can build a working, easily replicated experiment. And or they can work on developing a proven theory and work on getting it accepted.

#### birchoff

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##### Re: EM Drive Developments - related to space flight applications - Thread 2
« Reply #1673 on: 04/06/2015 08:37 pm »
Given the figures the predicted thrust that paul march provided us. Anyone mind educating this lay person on how a single EmDrive thruster would perform vs our current rockets.

#### Chrochne

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##### Re: EM Drive Developments - related to space flight applications - Thread 2
« Reply #1674 on: 04/06/2015 08:55 pm »
Does anyone actually believe that if we had a working EmDrive with the predicted thrust capabilities that we would have a problem finding power for it?

....

So from where I am standing, power will not be an issue if the EmDrive is proven to deliver usable thrust. We as a species will find a way.

I fully agree. Fretting about the energy source is a bit too much at this stage, when conclusively proving the existence of the phenomenon has yet to happen.

If this becomes a proven scientific fact, with a few more conclusive replications, finding a power source for it is just an engineering problem. That is, one based on the application of already known scientific and technical principles. We know nukes work and we have them, we know fuel cells work and we have them, the same as solar photovoltaics, etc.

Gee, if Emdrives are proven to work as H. White and Paul M. expect, we would be soon putting gasoil engines/generators to power them, and this for replacing turbofans/propellers for flying in the low atmosphere!

I fully agree with you. Especially on the last part. If it will do, what it looks like it may, we stand on the verge of unprecedented change to the world. And of course not only that. It is a dream for many to reach Europa (moon) and dig in. We could even make a base there.

Of course for us down here on Earth it would mean revolution in the transportation as Roger Shawyer predicted. It is even more far reaching than that. We would not be discussing this here, if not for this man. He was pushing for this for decades and the critics were just demolishing each move he done. I am so glad he did not give up.

Mr. Shawyer, if you are reading this I want to say thank you for not giving up.

What will results show I leave to brilliant minds of scientists and engineers here, but I am glad for this great debate.
« Last Edit: 04/06/2015 08:58 pm by Chrochne »

#### Abyss

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##### Re: EM Drive Developments - related to space flight applications - Thread 2
« Reply #1675 on: 04/06/2015 09:17 pm »
When doing EM simulations you can model the transient propagation of radiation as it interacts with your model, which can be valuable to see exactly how it reflects and interacts with various features (like a groove, slit, etc).  In this case you model an incoming pulse, composed of many frequencies.

Another common simulation is to do a frequency domain simulation in which you compute the steady state solution of inputting a single frequency into the model.  But you have to be careful in how you interpret these results, because they are non intuitive, e.g. they don't show the propagation of radiation.

I know you can perform both types of simulation using COMSOL and CST.

I have a few questions that perhaps the emdrive experts here can answer.  Why don't we use much smaller cavities? I believe they would be easier to machine, and experimentally work with.  This would require scaling the wavelength, but what is the problem with that?

#### Star One

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##### Re: EM Drive Developments - related to space flight applications - Thread 2
« Reply #1676 on: 04/06/2015 09:37 pm »
One thing that has mystified me about this whole business is it not the fact that this effect has been known about for a number of years so why is it only in recent years that people have started looking into it?
« Last Edit: 04/06/2015 09:39 pm by Star One »

#### Abyss

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##### Re: EM Drive Developments - related to space flight applications - Thread 2
« Reply #1677 on: 04/06/2015 09:46 pm »
One thing that has mystified me about this whole business is it not the fact that this effect has been known about for a number of years so why is it only in recent years that people have started looking into it?

It's not clear, what effect are you referring to?

#### Rodal

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##### Re: EM Drive Developments - related to space flight applications - Thread 2
« Reply #1678 on: 04/06/2015 10:30 pm »
When doing EM simulations you can model the transient propagation of radiation as it interacts with your model, which can be valuable to see exactly how it reflects and interacts with various features (like a groove, slit, etc).  In this case you model an incoming pulse, composed of many frequencies.

Another common simulation is to do a frequency domain simulation in which you compute the steady state solution of inputting a single frequency into the model.  But you have to be careful in how you interpret these results, because they are non intuitive, e.g. they don't show the propagation of radiation.

I know you can perform both types of simulation using COMSOL and CST.

I have a few questions that perhaps the emdrive experts here can answer.  Why don't we use much smaller cavities? I believe they would be easier to machine, and experimentally work with.  This would require scaling the wavelength, but what is the problem with that?
Welcome to the forum

The smaller the cavity, the higher the natural frequencies.  Shawyer's and NASA Eagleworks first truncated cones with flat ends were literally "home made" from thin copper sheets.  Using a conventional magnetron used for microwave ovens (2.45 GHz) the size for Shawyer's (the first one to do these experiments) was mainly dictated by the frequency of the lowest natural frequencies. (One should take into account the cut-off frequency condition).

One of the main contributors to this thread (@Notsosureofit) has posted that he plans to run his own tests with a significantly smaller EM Drive geometry using a Gunn diode to excite the microwaves at a higher frequency (using the X band (8 to 12 GHz) ), as used in the older radar speed guns used by the highway patrolmen
« Last Edit: 04/06/2015 11:11 pm by Rodal »

#### aceshigh

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##### Re: EM Drive Developments - related to space flight applications - Thread 2
« Reply #1679 on: 04/06/2015 10:47 pm »
Does anyone actually believe that if we had a working EmDrive with the predicted thrust capabilities that we would have a problem finding power for it?

....

So from where I am standing, power will not be an issue if the EmDrive is proven to deliver usable thrust. We as a species will find a way.

I fully agree. Fretting about the energy source is a bit too much at this stage, when conclusively proving the existence of the phenomenon has yet to happen.

If this becomes a proven scientific fact, with a few more conclusive replications, finding a power source for it is just an engineering problem. That is, one based on the application of already known scientific and technical principles. We know nukes work and we have them, we know fuel cells work and we have them, the same as solar photovoltaics, etc.

Gee, if Emdrives are proven to work as H. White and Paul M. expect, we would be soon putting gasoil engines/generators to power them, and this for replacing turbofans/propellers for flying in the low atmosphere!

I believe because of their extremely contentious nature & reputation to the majority in the scientific community it's not just a case of showing EM drives work but producing a rock solid case for why they work. Unfortunately there has been so many other claims of a similar nature that have been made over the years that have proved to be nonsense that it has severely muddied the waters leaving things such as the EM drive with incredibly high hurdles to clear before anyone gives them the time of day.

which is why I replied to Paul on the issue of power source when he mentioned LERN.

the issue didnīt really started as a discussing about whatīs the best power source... I donīt really care what will the power source, nor am I interested in discussing here which power producing method has the most potential, whatever.

the issue I had here was how the scientific community looks at the EM Drive and the Eagleworks Lab experiments,which ARE fringe, and how will they look at what is already considered fringe physics if powerpoint presentations include LERN stuff...

Am I that wrong in those fears?

Given the figures the predicted thrust that paul march provided us. Anyone mind educating this lay person on how a single EmDrive thruster would perform vs our current rockets.

well, itīs about 1250 kN is about two times the thrust of a Merlin 1D engine from the Falcon 9...

he also mentioned 1 million of ISP... I guess thatīs like having the power of a Merlin 1D engine consuming the same fuel per second as an electric bycicle??

I GUESS a single one would be enough to counter gravity and take a Falcon 9 rocket to space. However, because of the Falcon 9 weight and the thrust equivalent of only 2 merlin engines, it would probably take longer to get to orbit (which as you know is a matter of speed, not height).

But considering the ISP of 1 million (so little fuel being consumed per second) it HAS THE TIME to accelerate to orbital speed in the vacuum, while a normal rocket doesnīt have it (fuel ends fast, if it hasnt reached orbital speed, it falls).

I guess you could use it at like 45 degrees angle... half of thrust to keep it in space vacuum while the other half is horizontal speed to gather orbital speed?

Once in orbit... a single motor with 1250 N of thrust and 1 million of ISP can do wonders. Anyone wants to calculate the acceleration possible with such motor and a ship the weight of a fully loaded Falcon 9? (after all, he asked how it compared to current rockets)

« Last Edit: 04/06/2015 11:01 pm by aceshigh »

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