Author Topic: EM Drive Developments - related to space flight applications - Thread 3  (Read 1797815 times)

Offline WarpTech

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Just needs some vibration.

The EMDrive is an inertial ratchet. Push it on the small end and it will oppose that push, moving into Generator mode. Push it on the big end and it will support that push, moving into Motor mode.
...

Ha!... It doesn't exert any thrust due to the microwaves because Maxwell's equations say it can't. But it does store energy and that energy will have a back-reaction when you push it, which will be just as asymmetrical as the cavity attenuation.

Well done. I'll accept that.

Like your bike wheel example, once you flip it into Motor or Generator mode, it will stay there as long as there is an external force, which can be just simple vibration.

If you look at this slide, Shawyer clearly shows the momentum generates no external Force.

This diagram "slide" you keep showing is wrong, period. I spent a lot of time crunching numbers over the past week and I did a proper relativistic analysis of this diagram, 3 different ways! Using SR velocity addition/subtraction, using Lorentz Transformations and using Maxwell's equations. I took the walls into consideration as well as the 2 end plates.

In all 3 instances, pw = 0. There is no residual momentum transfer to the frustum with microwaves. Sorry, it just doesn't work this way. The "proof" it doesn't work this way is in this strange behavior you are aware of, that it will not thrust unless you give it a push. If it actually worked the way this diagram says it does, it would not require a push to get rolling.

It is possible that pushing it backwards offers resistance such that it appears more massive, where pushing it forward it appears less massive and tends to accelerate easier. But who's going to give a satellite a "push" in space?
Todd

Offline rfmwguy

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Offline wallofwolfstreet

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I have some interesting information to report that will be a bit of an interlude from the rigors of coding and FEM analysis.  This is purely background info that may or may not be interesting to some, and may or may not have been posted before. 

The oldest patent that Roger Shawyer has on emdrives is GB 2,229,865 (Electrical propulsion for spacecraft), which was filed on November 1st 1988, and is specifically for the design of a cylindrical cavity in which a dielectric is inserted at one end.  What interests me about this patent is that I always believed that Shawyer had only been thinking about these drives since around 2000.  This patent moves the beginnings of the emdrive all the way back to 1988.  Also intriguing is that failure to pay maintenance fees resulted in the patent becoming ineffective as of 1997, only one year before Shawyer filed for a second patent (for a conical frustum with dielectric insert).  Perhaps he found that the cylinder with dielectric insert wasn't effective?

Source: https://www.ipo.gov.uk/p-ipsum/Case/PublicationNumber/GB2229865 
Patent:  http://worldwide.espacenet.com/publicationDetails/originalDocument?CC=GB&NR=2229865A&KC=A&FT=D&ND=3&date=19901003&DB=EPODOC&locale=en_ES

In total, Shawyer seems to have applied for four emdrive related patents, including this 1988 one.  Three were granted, whilst one that was filed in 2011 has not yet been subjected to a first examination.  This last patent verifies that Shawyer believes curved endplates are the way to go, and I believe it has been posted here before.  If not, here is the link:  http://worldwide.espacenet.com/publicationDetails/originalDocument?CC=GB&NR=2493361A&KC=A&FT=D&ND=3&date=20130206&DB=EPODOC&locale=en_ES

After examining the patents, I did some digging specifically on SPR ltd to see if there was anything interesting there.  Using the Companies house database, we find the following:

1)  The company was originally incorporated on 27/10/2000.

2)  The corporate secretary is a Mr. Michael Kenneth Sheridan, who is a director of many (>15) companies that share the same headquarters address.  This is not uncommon for small companies.

3)  From the 2014 annual return, we see that Mr. Shawyer was born in 30/07/1947.  Just interesting to note it will be his 68th birthday next month.  If he reads this sub, it might be nice to wish him a happy birthday.

4)  Also from the 2014 annual return, we see that there are a total of 10 investors.  Mr. Shawyer has control with 62% of the shares, and Mr. Sheridan has the next greatest portion at 12%.  Each one of these shares was sold for a pound (at 62%, Shawyer only has 700 share himself).   

5)  From the 2014 total exemption small company accounts (also under filing history tab), we get to see some of the financials.  SPR is in debt to the tune of 240 thousand pounds.  With total assets valued at only 5 thousand pounds, SPR is on the hook for 235 thousand pounds with an almost non-existent cash position.  This financial picture might explain why Shawyer has so few patents, no employees and a very slow development path. 

Source:  https://beta.companieshouse.gov.uk/company/04097991
Source for 2014 returns:  https://beta.companieshouse.gov.uk/company/04097991/filing-history
« Last Edit: 06/24/2015 06:42 PM by wallofwolfstreet »

Online Rodal

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...
4)  Also from the 2014 annual return, we see that there are a total of 10 investors.  Mr. Shawyer has control with 62% of the shares, and Mr. Sheridan has the next greatest portion at 12%.  Each one of these shares was sold for a pound (at 62%, Shawyer only has 700 share himself).   

5)  From the 2014 total exemption small company accounts (also under filing history tab), we get to see some of the financials.  SPR is in debt to the tune of 240 thousand pounds.  With total assets valued at only 5 thousand pounds, SPR is on the hook for [/b]235 thousand pounds[/b] with an almost non-existent cash position.  This financial picture might explain why Shawyer has so few patents, no employees and a very slow development path. 

Source:  https://beta.companieshouse.gov.uk/company/04097991
Source for 2014 returns:  https://beta.companieshouse.gov.uk/company/04097991/filing-history

Very interesting information.  According to the above information, Shawyer's company appears to be in a very weak financial position: the almost non-existent cash position, and total assets valued at only 5 thousand pounds is particularly alarming to investors.

What would be of value to investors to compensate for your reported "235 thousand pounds" in debt would be his patents and technology, but his 3 granted patents appear to be Great Britain patents, instead of European patents or US patents.  GB patents are only enforceable in the UK, is that right?

Don't you need a US patent to enforce a patent in the US?

It looks like he has a lot riding in his later paper that TheTraveller says is under peer-review, and to demonstrate the practical success of this technology.
« Last Edit: 06/24/2015 06:33 PM by Rodal »

Offline graybeardsyseng

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[...
Indeed, in the UK when the background force changes were eliminated, in an effort
to improve force measurement resolution, no EmDrive force was measured.
This
was clearly a result of attempting to measure the forces on a fully static thruster,
where T and R cancel each other.

...

So, with the EM Drive in deep space, or at a Lagrangian point, where there are no external background forces, the EM Drive would be unable to exert a force on the spaceship and it would just sit still?

Why do you always go to the extreme point?

There is ALWAYS vibration in any ship. Pumps, motors, compressors, etc. If needed simple to rig up a vibrator to kick things off.

If you tell the design engineer it needs an external vibrators source at switch on, no problems. Gets designed into the EMDrive support systems.

Wait. Did you just say that they have to smack it with a hammer to get it to work?

I was thinking of something similar to the Coffman starters used on large piston engines in aircraft in WW2 (aka Shotgun Starter)  - good example in movie "Flight of the Phoenix".

So for our spaceship it would be something like - A) Insert new cartridge in the "impulse engine" - small tube heading aft,  B) Engage EMDRIVE,  C) Fire Cartridge and nudge ship, D) Ahead Warp One.

Seriously though - there are a lot of devices that need a nudge to start or move them out of a metastable state.

Herman

EMdrive - finally - microwaves are good for something other than heating ramen noodles and leftover pizza ;-)

Offline flux_capacitor

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@wallofwolfstreet, your link to the last patent returns a blank screen, so I repost all the links for the four Shawyer's patents below:

GB application 2229865, Shawyer, Roger John, "Electrical propulsion unit for spacecraft", filed 1988-11-01, published 1990-10-03
GB application 2334761, Shawyer, Roger John, "Microwave thruster for spacecraft", filed 1998-04-29, published 1999-09-01
GB application 2399601, Shawyer, Roger John, "Thrust producing device using microwaves", filed 2003-03-13, published 2004-09-22
GB application 2493361, Shawyer, Roger John, "A high Q microwave radiation thruster", filed 2011-08-01, published 2013-02-06

And since the original web site for patents is not really user-friendly, I attached the PDF versions to this message, much easier to read :)

The shape of the EmDrive in the last patent, no longer a truncated cone, is interesting. Note also that the second patent (a truncated conical cavity with a dielectric inside) was filed ten years after the first (a cylindrical cavity with a dielectric inside) but was published slightly before! That could explain why Shawyer didn't bother to pay the fee to maintain a patent for an obsolete design (the cylinder) in favor of a more effective one (the frustum).
« Last Edit: 06/24/2015 06:52 PM by flux_capacitor »

Offline deltaMass

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Is there any actual physics behind this "get out and push to select a Mode" business?  8)

Offline wallofwolfstreet

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...
4)  Also from the 2014 annual return, we see that there are a total of 10 investors.  Mr. Shawyer has control with 62% of the shares, and Mr. Sheridan has the next greatest portion at 12%.  Each one of these shares was sold for a pound (at 62%, Shawyer only has 700 share himself).   

5)  From the 2014 total exemption small company accounts (also under filing history tab), we get to see some of the financials.  SPR is in debt to the tune of 240 thousand pounds.  With total assets valued at only 5 thousand pounds, SPR is on the hook for [/b]235 thousand pounds[/b] with an almost non-existent cash position.  This financial picture might explain why Shawyer has so few patents, no employees and a very slow development path. 

Source:  https://beta.companieshouse.gov.uk/company/04097991
Source for 2014 returns:  https://beta.companieshouse.gov.uk/company/04097991/filing-history

Very interesting information.  According to the above information, Shawyer's company appears to be in a very weak financial position: the almost non-existent cash position, and total assets valued at only 5 thousand pounds is particularly alarming to investors.

What would be of value to investors to compensate for your reported "235 thousand pounds" in debt would be his patents and technology, but his 3 granted patents appear to be Great Britain patents, instead of European patents or US patents.  GB patents are only enforceable in the UK, is that right?

Don't you need a US patent to enforce a patent in the US?

It looks like he has a lot riding in his later paper that TheTraveller says is under peer-review, and to demonstrate the practical success of this technology.

Yes, Patents are only enforceable in the country in which you have them.  Specifically, they give you the right to exclude others from:

1) Selling
2) Offering for sale
3) Manufacturing
4) Importing

within the country you have the patent.  Effectively, a company in the US can do whatever they want with the emdrive. 

Getting an aerospace patent only in the UK is a very strange practice, especially if you really believed you were sitting on a billion dollar opportunity.  A strong patent will have been filed in many countries, and the US is usually first on that list for any sort of high tech equipment.
« Last Edit: 06/24/2015 06:49 PM by wallofwolfstreet »

Online aero

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Somewhere I picked up the idea that international patents are an option.
Retired, working interesting problems

Online Rodal

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@Rodal

1- The frequency for the Brady-Rodal cavity, 2.14 GHz, was set for resonance. It resonates at a different frequency than does the Brady cavity, 1.95 GHz.

2- The output from the Meep runs depends on what I ask for in the control file. I have been asking for Ez, the z component of the electromagnetic field within the cavity. What the images show is the Ez component of the electromagnetic field as viewed from the x, y, and z directions. At any given time step you are viewing exactly the same field, just from a different angle.

The complete electromagnetic field, EMF = Ex + Ey + Ez + Hx + Hy + Hz as I understand it. These field components are output in Meep (Natural) units which assumes the speed lf light equals 1, and the distance scale factor equals 0.3 meters. Converting to SI units is not so meaningful in absolute terms as Meep automatically controls the drive power by some unknown means and the manuals don't clarify how. The Manuals do suggest that the Amplitude can be changed to calculate relative field strengths. That is two runs with MatLab data reduction.

If you want to see the complete E field, Ex + Ey + Ez, I believe I could output all of them from the same run, (same for H). They would be in their own individual files so again that would require some MatLab data combining and reduction in order to see viable results.

In any case you need to describe in detail what you want to see, then put it somewhere so that it won't get lost in the back thread as pages of posts are added here. Requests for information scattered throughout this very long thread just get lost as I don't have the time, skills or motivation to consolidate them into something meaningful.

1) Don't understand <<1- The frequency for the Brady-Rodal cavity, 2.14 GHz, was set for resonance. It resonates at a different frequency than does the Brady cavity, 1.95 GHz. >> QUESTION: are you exciting the pointy Brady cavity at 2.14 GHz?  or are you saying that it resonates at 2.14 GHz ?  (and if so, what is this resonance based on?)

2) I would better re-state your statement <<At any given time step you are viewing exactly the same field, just from a different angle.>> [it should say instead "exactly the same field component]" because what you are plotting is not the Electric Field as an invariant force vector object, what you are plotting is the Ez component which is based on the arbitrary orientation of your Cartesian coordinate system and the arbitrary choice of Cartesian coordinates.   Plotting Sqrt[[Ex^2+Ey^2+Ez^2] would be plotting the Electric Field, it would be the absolute value of the electric field independent of arbitrary choices of coordinate systems.

3) I would prefer to see the electric field vectors, in a vector field plot. Otherwise to plot contour plots of the absolute value of the electric and magnetic vectors: for the electric field vector: Sqrt[[Ex^2+Ey^2+Ez^2] and the magnetic field vector Sqrt[[Hx^2+Hy^2+Hz^2] separately. 

4) Not interested in the electromagnetic Energy Density for the time being.

5) If it is unwieldly to output and plot the electric field  Sqrt[[Ex^2+Ey^2+Ez^2] and the magnetic field  Sqrt[[Hx^2+Hy^2+Hz^2] separately, I would settle for seeing the Cartesian component Hx for the time being (the magnetic field in the longitudinal section, for a TE mode)

6) The most important thing at this point in time is to get NUMBERS, because at the moment we have no idea of the magnitude of Ez in the z view vs the x view.  One shows a very asymmetric contour plot from the antenna, and the other one shows a plot that looks more like what one expects the standing waves to look like.  Unless we get numbers we have no idea of whether one field is negligible in comparison to the other.

Viewers may incorrectly assume that you are plotting all the contour plots to the same range, while it is very likely that you are not plotting the same range, but instead you are plotting different magnitude ranges, betwen minimum and maximum in every case, so that a contour plot with very small numerical values may be misconstrued to be significant by an observer not aware of this fact.
« Last Edit: 06/24/2015 07:00 PM by Rodal »

Offline wallofwolfstreet

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Somewhere I picked up the idea that international patents are an option.

Kind of, but not really.  As of right now, there is no such thing as a patent that gives you protection in the entire world (while there is a system specific to some european countries).  The Patent Cooperation Treaty (PCT) creates a standardized filing option that allows you to define a single priority date for your application that then applies to all of your national filings.  It also decreases the cost of going from the PCT stage to the national stage compared to filing in each individual country.

In essence you file a single patent application with the PCT, and they give you 18 months to decide all the different countries you wish to individually file in.  You then pay national fees to get these nation specific patents, but it costs less because you paid some costs upfront when you applied through the PCT. 

If you only want your patent in one country, the PCT route would likely cost more.  If you want many patents in many countries, the PCT route saves time, money and streamlines the process.  It still requires you to obtain nation specific patents however.
« Last Edit: 06/24/2015 08:14 PM by wallofwolfstreet »

Online SeeShells

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Somewhere I picked up the idea that international patents are an option.
You can spend tons on global patents and then trying to protect them becomes another money pit. Even if you do all of that you'll see a knockoff pop up in Singapore of somewhere else where it's almost impossible to stop.
If you're smart you'll bury your IP behind a picket fence and not disclose the gory tell all tech details on how and why it works. If money is tight and you're trying to grow with debt and have little or no revenue stream, you publish (and even apply for a patent) a simplistic model of your idea, leaving out really what makes it work.
What RS needs is a little revenue stream to show a positive cash flow. I would not want to try what he is doing with so little.
Shell

Offline rfmwguy

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...
4)  Also from the 2014 annual return, we see that there are a total of 10 investors.  Mr. Shawyer has control with 62% of the shares, and Mr. Sheridan has the next greatest portion at 12%.  Each one of these shares was sold for a pound (at 62%, Shawyer only has 700 share himself).   

5)  From the 2014 total exemption small company accounts (also under filing history tab), we get to see some of the financials.  SPR is in debt to the tune of 240 thousand pounds.  With total assets valued at only 5 thousand pounds, SPR is on the hook for [/b]235 thousand pounds[/b] with an almost non-existent cash position.  This financial picture might explain why Shawyer has so few patents, no employees and a very slow development path. 

Source:  https://beta.companieshouse.gov.uk/company/04097991
Source for 2014 returns:  https://beta.companieshouse.gov.uk/company/04097991/filing-history

Very interesting information.  According to the above information, Shawyer's company appears to be in a very weak financial position: the almost non-existent cash position, and total assets valued at only 5 thousand pounds is particularly alarming to investors.

What would be of value to investors to compensate for your reported "235 thousand pounds" in debt would be his patents and technology, but his 3 granted patents appear to be Great Britain patents, instead of European patents or US patents.  GB patents are only enforceable in the UK, is that right?

Don't you need a US patent to enforce a patent in the US?

It looks like he has a lot riding in his later paper that TheTraveller says is under peer-review, and to demonstrate the practical success of this technology.

Well worth updating main wiki pages with prior patent/design information from 1988:

https://en.wikipedia.org/wiki/Roger_Shawyer and https://en.wikipedia.org/wiki/EmDrive

Online SeeShells

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Slower version of Y plot by Aero.
Will try a BW version.

Online aero

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@Rodal -  Resonance is as detected by Harminv. While  the frequency may not be the exactly correct value from the real world, or the analytical solutions, it is the frequency that gives "strong" field images. IF you want to see a cavity without a resonant drive frequency, well, it looks like a candle flame. Just hold a lighted candle in a slight breeze and watch it flicker.
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Online aero

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Slower version of Y plot by Aero.
Will try a BW version.

When I get a couple of hours to spare, I'll upload a set of .png files with finer time resolution. It's not difficult, just time consuming.
Retired, working interesting problems

Offline dustinthewind

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...

In other words, does accelerating the frustum in one direction change the resonance mode, while accelerating in the other does not? And will the resonance mode significantly resist being changed?
For that to happen, the mechanical acceleration would have to be huge, since the electromagnetic field frequency is in the GHz range.  But, on the contrary, the reported EM Drive accelerations instead of being huge, it is extremely tiny: in the only EM Drive experiment that experienced significant rigid body motion: Shawyer's Demo on an air bearing, it takes several minutes for the EM Drive to complete a circumference,  Extremely small acceleration.


Maybe it is possible there could be vibrations in the GHz range.  There is radiation pressure  and microwaves are in the GHz range.  We also have that pressure amplified by the Q of the cavity and possibly phase relationships inducing vibrations. 

Online Rodal

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@Rodal -  Resonance is as detected by Harminv. While  the frequency may not be the exactly correct value from the real world, or the analytical solutions, it is the frequency that gives "strong" field images. IF you want to see a cavity without a resonant drive frequency, well, it looks like a candle flame. Just hold a lighted candle in a slight breeze and watch it flicker.
I don't understand why you write << IF you want to see a cavity without a resonant drive frequency, well, it looks like a candle flame. Just hold a lighted candle in a slight breeze and watch it flicker.>>

I am not a mind reader :)  .  Previously you were referring to the excitation frequency, and you listed several frequencies at which it could resonate.

This time you are not saying what the excitation frequency from the antenna is.  This time instead of listing a number of resonant frequencies you are referring to a resonant frequency based on HarmInv.
« Last Edit: 06/24/2015 07:46 PM by Rodal »

Offline flux_capacitor

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Well worth updating main wiki pages with prior patent/design information from 1988:

https://en.wikipedia.org/wiki/Roger_Shawyer and https://en.wikipedia.org/wiki/EmDrive

Side note on this topic and my own advice: don't waste your time on Wikipedia. I tried to point to those patents once on the main EmDrive wikipedia page, but the links were immediately deleted because being "irrelevant". Actually any source from Shawyer (web page or PDF paper) is withdrawn from Wikipedia by people monitoring the page 24/7, as Shawyer's documents are considered orignal research and a primary source.

Even peer-reviewed papers published by secondary sources (Fernando Minotti, Mike McCulloch…) are immediately withdrawn because also being "irrelevant" (but not Dr White's papers or negative comments by John Baez or Sean M. Carroll, although not peer reviewed…). This has resulted in a very poor "Theory" section in the article. Wikipedia is not a place for groundbreaking science. It is a place for well established facts.

This forum is a place for groundbreaking science!

Offline rfmwguy

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Slower version of Y plot by Aero.
Will try a BW version.

Nice work shell, somewhere I had used a free movie program that "morphed" slides (pics) in sequential transition rather than hard jumping. I'll look for it at home, think it might make a good movie.

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