Author Topic: EM Drive Developments - related to space flight applications - Thread 3  (Read 1804900 times)

Offline rfmwguy

  • EmDrive Builder (retired)
  • Senior Member
  • *****
  • Posts: 2165
  • Liked: 2681
  • Likes Given: 1124
Move along...nothing to see here: https://www.jannaf.org/mtgs/June2015/pages/sps.html

Actually, there is... ;)
Or to put it another way - no EmDrive, anywhere
Think the name emdrive is a no-no with this crowd (don't acknowledge shawyer's device?). Q thruster is the word o' the day which also doesn't appear. However, there are several other specific and several "foggy" Propellantless topics. Battle of the solar sail advocates (like Bill Nye) versus the world it appears.

Key here is jannaf exists and is a VERY high level org. Secondly, they have "propellantless" on their agenda. Thirdly, it is highly restrictive to attend and present. Fourthly (is that a word ;) ), nothing will be made public on presentations, some are classified. Its a dark-dark world we live in.

Takes no conspiracy theorist to acknowledge propellantless propulsion is in a buzz role right now and rocket men must be taking note. I would if I ran a company active in propulsion technology.
« Last Edit: 06/26/2015 04:07 PM by rfmwguy »

Offline Star One

  • Senior Member
  • *****
  • Posts: 8020
  • UK
  • Liked: 1281
  • Likes Given: 168
He might well be leaving bread crumbs but who is going to bother following them now?
« Last Edit: 06/26/2015 04:05 PM by Star One »

Offline Rodal

  • Senior Member
  • *****
  • Posts: 5845
  • USA
  • Liked: 5925
  • Likes Given: 5269
I would like to say, that I appreciate @TheTraveller's enthusiasm for Mr. Shawyer's work (not to mention the value of his personal relationship to him) and hope he returns to the discussion.  He has for sure, provided unique data points to this forum, Reddit, and in particular the wiki (I'm the guy who set it up).

We can probably all agree that Mr. Shawyer appears to be in a difficult position, where any desire he may have to announce details (theoretical or experimental) would  be at odds with any existing licensing agreements.  The various DIY'ers here thankfully don't have that problem (yet!). 

Any crumbs dropped in the meantime (see: @TheTraveller, Paul March, etc.) will continue to be insufficient to satisfy the audience in one way or another, no matter what they were.  Perhaps we could crowdsource some marketing consultants for SPR Ltd. to help manage the public expectations better?  :)

If the phenomenon is real, the huge possibilities here, mean this vacuum is filled with speculation; unfortunately some of this drifts into personal attacks.  I do hope @TheTraveller disregards these and rejoins the conversation.

-Rolf

Rolf, I just wanted to address a specific part of your quote, namely:

Quote
We can probably all agree that Mr. Shawyer appears to be in a difficult position, where any desire he may have to announce details (theoretical or experimental) would  be at odds with any existing licensing agreements.

I have commented a few times, at least with my reddit posts, that I am very skeptical that any such licensing agreements actually exist.  I am also skeptical that there are many, if any at all, private companies working on this tech.  I know this goes against what we have heard from Shawyer, but I have reason to doubt what he says.

Simply put, All of Shawyer's patents are in the UK alone.  He claims that the west is not developing technology, and that "we need to think about the developing countries that don't have a vested interest in the long-haul aircraft market" (paraphrasing).  He claims that these mysterious countries/companies have licensing agreements, and this is the cause of his silence. (At least thetraveller was of this opinion, which he may have heard directly from Shawyer).

Here is the kicker though:  A foreign country/company, outside of the UK, has zero obligation to have an sort of licensing deal with SPR whatsoever.

SPR's patents are only in the UK.  China or India, or any organization therein, has zero need to license anything.  He has nothing they need.  They can go online and read his patents, or look at his papers, just like we can.  I see absolutely no reason why a private company would have a licensing agreement with SPR, it has no patents outside of the UK to license! 

Edit: Rodal already covered this above.

I am not sure if the attached has been covered on here before but it states "EmDrive Licence: 10 year exclusive master licence £100,000,000 comprised of
2 years development to Flight Qualified status @ £10m per year pro rata, plus
consultancy from Roger Shawyer to divest expertise.
Break clause at 2 years, if project fails to achieve FQ status all rights revert to SPR.
A further 3 year exclusive use of EmDrive @ £10m per annum.
After 3 years of exclusive use, master licensee is required to sub licence technology on
similar terms, if requested, to third parties.
For 10 years, royalties of £150k per space vehicle using EmDrive (equivalent to 10% of
the saving on build cost).
After 10 years, master licensee has first right of refusal on renewing master licence"


I know this possibly quite old but may be of interest.

Mike.

The injection of 250,000 British Pounds equals the same old 250,000 pounds that WallofWolfStreet disclosed SPR presently owes.  So, unless this is a coincidence, it looks like the "injection" was really a LOAN, that SPR owes.  On the other side of the ledger WallofWolfStreet  disclosed that capital at the moment is only 5,000 pounds.

So nothing resembling the proposed Licensing agreement seems to have materialized.

Please note (bold for emphasis):

Quote
It is proposed to licence the technology on an exclusive
basis to an initial partner to take the product to a flight
qualification stage (18 – 24 months), to have them build and operate satellites using the
technology, and later to offer the technology on a sub-licence basis.
The minimum value of such a licence over 10 years would be in the region of £100,000,000
plus royalties.

This was a proposal.  If it would have materialized, SPR would have  £100,000,000 instead of owing £250,000 according to what WallofWolfStreet has uncovered.

Certainly a HUGE gap from what was proposed to be the Licensing agreement, and the reality,
as uncovered by WallofWolfStreet.

From the writing one has to wonder whether the << initial partner to take the product to a flight
qualification stage (18 – 24 months), to have them build and operate satellites using the
technology, and later to offer the technology on a sub-licence basis>> was supposed to be Boeing, as this could very well be a description for the Flight Thruster project.



« Last Edit: 06/26/2015 04:28 PM by Rodal »

Offline kdhilliard

  • Full Member
  • *
  • Posts: 171
  • Kirk
  • Tanstaa, FL
  • Liked: 162
  • Likes Given: 523
I am not sure if the attached has been covered on here before but it states

"EmDrive Licence: 10 year exclusive master licence £100,000,000 comprised of
2 years development to Flight Qualified status @ £10m per year pro rata, plus
consultancy from Roger Shawyer to divest expertise.
Break clause at 2 years, if project fails to achieve FQ status all rights revert to SPR.
A further 3 year exclusive use of EmDrive @ £10m per annum.
After 3 years of exclusive use, master licensee is required to sub licence technology on
similar terms, if requested, to third parties.
For 10 years, royalties of £150k per space vehicle using EmDrive (equivalent to 10% of
the saving on build cost).
After 10 years, master licensee has first right of refusal on renewing master licence"


I know this possibly quite old but may be of interest.

Mike.

Source: http://ind-tech.com/wp-content/uploads/2014/11/Investment-Memorandum-final.pdf
This is an Investment Memorandum.  The quote comes from section six "Financial Information", and is preceded by, "The company believes that in the next 9 months it can negotiate an exclusive licence and royalty structured in the following way."

~Kirk

Offline WarpTech

  • Full Member
  • ****
  • Posts: 1229
  • Do it!
  • Vista, CA
  • Liked: 1296
  • Likes Given: 1753
@WarpTech, @notsosureofit, and others...
....<snip>

The duty cycle would be:
- Pluck the string and give it some energy.
- Compress it on the side that "exposes less inertial mass".
- Re-expand it on the side that "exposes more inertial mass".
- Measure net velocity imparted to the system, and the energy of the wave in the string.
- Hopefully for CoE the kinetic energy gained will be related to the energy lost by the wave in the string.

Does this make sense as a thought experiment, or even as a physical experiment?
Or am I going completely off track and totally missed something?

I play guitar too, so I had the same idea! :) Vary the linear mass density by making the string gradually thicker. Waves will have different velocity on each end. As such, it does model the frustum. My conclusion is the same as well. When the standing wave reaches the ends of the string, at one end, the string has more mass and less velocity, at the other end it has less mass and higher velocity. The momentum striking each end, plus the change in momentum along the length of the string, results in a NET-0 momentum transfer to the string supports (bridge & nut).

If you push it from either end, it will do as you said, resist in one direction gain in the other. But since I was just schooled on this, I will school everyone here too. :-/ The issue is, when you push and it resists, the energy put in is then reflected toward the big end and when it is reflected at that end, whatever momentum was gained from the push is lost. Same thing happens in the other direction. NET momentum gained is zero!

The only way these things will work is to interact with an outside environment. I believe I've figured out that this mechanism is the finite conductivity of copper + heat, allowing voltage drop to form on the conductor, AKA "Ohm's Law". Where there is voltage and current there are volt-seconds, or magnetic flux that is passing through that open window. So heat and poor conductivity allow flux to escape (tunnel) through the copper. I've also found a mechanism to boost the force many times over that of a photon rocket, such that this little bit of energy that escapes may in fact be enough to cause the observed thrust.

More when I finish the paper...
Todd

Offline dustinthewind

  • Full Member
  • ****
  • Posts: 587
  • U.S. of A.
  • Liked: 228
  • Likes Given: 259
https://hal.archives-ouvertes.fr/jpa-00246781/document
On the other hand, the 60 mm length of this region corresponds to a delay time of 0.2 nsec of light in vacuum, this is clearly longer than the measured delay in the first 5 nsec duration of the pulse superluminal conditions are present both for the center of gravity and the maximum value of the electromagnetic packet. Furthermore this confirmes the correctness of the frequency domain data and the corresponding Fourier evaluation [2, 3]. The zerc-time traversal described in references [2] and [3] proves to be correct, I-e- there is no additional time delay caused by an additional length of the evanescent region.
<end quote>

I know group velocities can appear greater than the speed of light but because the wave form information was previously propagated at light speed.  I suspect that may be what is happening and maybe this is what this paper is also suggesting. 

https://scholar.google.com/scholar?cluster=3707515693059191286&hl=en&as_sdt=5,48&sciodt=0,48

It is an interesting question. 

hmm on a second maybe they are implying that group velocity can't explain the results? "Finally, we discussed a pos-sible interpretation of the results, favoring the argument that the group velocity cannot be interpreted as a tunneling ve-locity."  Fascinating.

I guess I am still skeptical that near field's can travel faster than light.  If that were so I don't know what would stop us from building a circular array and sending messages back in time.  That is actual signals that move faster than light would travel back in time like tachyons. 

Offline dustinthewind

  • Full Member
  • ****
  • Posts: 587
  • U.S. of A.
  • Liked: 228
  • Likes Given: 259

...I've also found a mechanism to boost the force many times over that of a photon rocket, such that this little bit of energy that escapes may in fact be enough to cause the observed thrust.

More when I finish the paper...
Todd

I would be interested to hear what component it could be that would multiply the thrust.  Would there be that much more radiation emitted? 

Online aero

  • Senior Member
  • *****
  • Posts: 2744
  • 92129
  • Liked: 705
  • Likes Given: 240
I found information about the original paper for Harminv, unfortuantely it is still behind a paywall. Here is the abstract.

Quote
Article
Harmonic inversion of time signals and its applications

    Vladimir A. Mandelshtam
    Vladimir A. Mandelshtam
    Howard S Taylor
    Howard S Taylor

Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Ángeles, California, United States
The Journal of Chemical Physics (Impact Factor: 3.12). 11/1997; 107(17):6756-6769. DOI: 10.1063/1.475324

ABSTRACT New methods of high resolution spectral analysis of short time signals are presented. These methods utilize the filter-diagonalization approach of Wall and Neuhauser [J. Chem. Phys. 102, 8011 (1995)] that extracts the complex frequencies ωk and amplitudes dk from a signal C(t) = ∑kdke−itωk in a small frequency interval by recasting the harmonic inversion problem as the one of a small matrix diagonalization. The present methods are rigorously adapted to the conventional case of the signal available on a sparse equidistant time grid and use a more efficient boxlike filter. Various applications are discussed, such as iterative diagonalization of large Hamiltonian matrices for calculating bound and resonance states, scattering calculations in the presence of narrow resonances, etc. For the scattering problem the harmonic inversion is directly applied to the signal cn = (χf,Tn(Ĥ)χi), generated by the dynamical system governed by a modified Chebyshev recursion, avoiding the usual recasting the problem to the time domain. Some challenging numerical examples are presented. The general filter-diagonalization method is shown to be stable and efficient for the extraction of thousands of complex frequencies ωk and amplitudes dk from a signal. When the model signal is “spoiled” by a moderate amount of an additive Gaussian noise the obtained spectral estimate is still superior to the conventional Fourier spectrum.

Of course for my purposes within Meep, Gaussian noise is added. Harminv runs for an infinite time when I try to use it without noise. And as mentioned previously the narrower the noise bandwidth the longer the run time.

It does appear, not suprisingly, as though the authors are quite proud of the technique.
Retired, working interesting problems

Offline D_Dom

  • Global Moderator
  • Full Member
  • *****
  • Posts: 456
  • Liked: 154
  • Likes Given: 105
I like thinking about standing waves. Whitewater kayakers can extract energy from the standing wave a rock causes midstream. Maybe not engineering "work" but certainly adrenaline pumping fun. No capability to model the turbulent flow I am more a hands-on type of guy. For many years I have been trying to learn enough to attempt my own build of a propellantless propulsion device.

 back to lurk mode
Space is not merely a matter of life or death, it is considerably more important than that!

Offline jmossman

  • Member
  • Posts: 72
  • San Jose, CA
  • Liked: 58
  • Likes Given: 173

I saw that in your information. I used traveller's spreadsheet, which is the only working spreadsheet publicly released, (many thanks Mr T.) and it came up with 185 mg of gram-force with a Q of 50K. Not expecting to see that type of Q, I scaled it back to 10K. Plug some numbers into the spreadsheet and see where gram force comes out. Your numbers would be far too small for EMDIYers to validate. Let me know.

That is the problem I have been having. My calculated values, by using experimental data found on the emdrive wiki, are far to small to be measured by the EMDIYer. So, I am a bit stuck on what to expect.

I don't have that kind of space to create what you have, so I have to figure out a smaller way of testing this thing.

If I achieve null results using the shawer inspired spreadsheet, then I would conclude his position is irrelevant. Reason I chose to follow it was its the only public tool I am aware of and its within a diyers measurement capability. Should nasa cough up a designers tool, which I highly doubt, I would consider it provided it doesn't require NIST to test the results.
But then, to be consistent with Shawyer, you have to use his mode shapes, Shawyer uses transverse ELECTRIC TE01 modes, just like Yang.  So you should choose the dimensions that give TE013 at 2.45GHz instead of the dimensions that give the transverse magnetic TM212 mode (used by NASA) at 2.45 GHz.

////////////////////////////////

bigDiameter = 11.01 inches;
smallDiameter = 6.25 inches;
axialLength = 10.2 inches;  NOTICE 10.2 inches -- in this case

with FLAT ENDs with a TRANSVERSE ELECTRIC MODE.  It resonates at 2.45044 GHz with TE013



////////////////////////////////

It would be inconsistent for you to use the  dimensions that give the transverse magnetic TM212 mode (used by NASA) at 2.45 GHz

@rfmwguy,

Please also keep in mind that to achieve the projected Q=50000 would likely require the use of spherically curved end plates.  (unless I misunderstood TheTraveller's description)

The use of flat end plates will result in a much smaller Q.  If I'm reading the emdrive.wiki correctly, I believe Shawyer's early attempt using flat end plates had a reported Q=5900.  I can't remember if the Q=5900 was with a tunable end plate, or if Q=45000 was the tunable end plate.

http://emdrive.wiki/Experimental_Results#cite_ref-Shawyer_Demonstrator_7-0
http://emdrive.wiki/Experimental_Results#cite_note-Shawyer_Demonstrator-7

In either case, I would suggest that anticipating a Q=10000 for your build is a bit....  optimistic.   :-[

Offline Rodal

  • Senior Member
  • *****
  • Posts: 5845
  • USA
  • Liked: 5925
  • Likes Given: 5269
https://hal.archives-ouvertes.fr/jpa-00246781/document
On the other hand, the 60 mm length of this region corresponds to a delay time of 0.2 nsec of light in vacuum, this is clearly longer than the measured delay in the first 5 nsec duration of the pulse superluminal conditions are present both for the center of gravity and the maximum value of the electromagnetic packet. Furthermore this confirmes the correctness of the frequency domain data and the corresponding Fourier evaluation [2, 3]. The zerc-time traversal described in references [2] and [3] proves to be correct, I-e- there is no additional time delay caused by an additional length of the evanescent region.
<end quote>

I know group velocities can appear greater than the speed of light but because the wave form information was previously propagated at light speed.  I suspect that may be what is happening and maybe this is what this paper is also suggesting. 

https://scholar.google.com/scholar?cluster=3707515693059191286&hl=en&as_sdt=5,48&sciodt=0,48

It is an interesting question. 

hmm on a second maybe they are implying that group velocity can't explain the results? "Finally, we discussed a pos-sible interpretation of the results, favoring the argument that the group velocity cannot be interpreted as a tunneling ve-locity."  Fascinating.

I guess I am still skeptical that near field's can travel faster than light.  If that were so I don't know what would stop us from building a circular array and sending messages back in time.  That is actual signals that move faster than light would travel back in time like tachyons.
I used to be not just skeptical, but, Ahem, hostile, to this idea of superluminal transmission, because of violation of causality, and the appearance that a tachyonic telephone could be constructed.

However, upon examining the papers in detail, there is no doubt in my mind that it is impossible to send information using this superluminal transmission.  It has been shown a number of times, by different authors that this is impossible, just as it is impossible to use the coherence phenomenon of instantaneous action at a distance to send information.  This is precluded by quantum mechanics, in both cases.  There is nothing deterministic about the superluminal evanescent wave transmission that can be used to send any information superluminally, as what will be received superluminally will be scrambled up randomly in a non-deterministic way.  The signal received at the other end would be incomprehensible and contain no information.

Hence I no longer have any problem with this type of superluminal action.  Besides the impossibility to use it to send information, the superluminal aspect is restricted to the group velocity and not to the phase velocity, so one has to be careful about the physical interpretation of this superluminal effect.
« Last Edit: 06/26/2015 05:24 PM by Rodal »

Offline vulture4

  • Full Member
  • ****
  • Posts: 987
  • Liked: 305
  • Likes Given: 89
but name a breakthrough...ion engines aside. There have been none.
Giant magnetoresistance, which multiplied hard drive capacity from a megabyte to a terabyte? If you mean spacecraft propulsion, the physics is somehat understood but the engineering and economics are changing radically.
Quote
We have enough accepted theories without solid experimental evidence, lets get some proof and let the theories catch up.../end ramble
* https://en.wikipedia.org/wiki/Role_of_chance_in_scientific_discoveries
The primary point of the Wikipedia article is that rigourous observation may yield unexpected information. In this case an unexpected effect has been postulated without observation.
« Last Edit: 06/26/2015 05:22 PM by vulture4 »

Offline hhexo

  • Member
  • Posts: 31
  • An Italian in the UK
  • Liked: 24
  • Likes Given: 1
I play guitar too, so I had the same idea! :) Vary the linear mass density by making the string gradually thicker. Waves will have different velocity on each end. As such, it does model the frustum. My conclusion is the same as well.
<snip>
But since I was just schooled on this, I will school everyone here too. :-/ The issue is, when you push and it resists, the energy put in is then reflected toward the big end and when it is reflected at that end, whatever momentum was gained from the push is lost. Same thing happens in the other direction. NET momentum gained is zero!

I see!
Thanks a lot Todd! Even if the theory has then been schooled as you say, and there is no net gained momentum at the end, at least now I have in my mind a visualization of how this theory worked, which I previously found hard due to the complexity of EM waves versus acoustic waves. The acoustic case is easier to understand, at least for me.

And in fact... since such a string (great idea about the variable thickness!) models the frustum, at least for the waves at resonance... Could we use it as a physical experiment to prove whether the EmDrive effect can be due to the waves at resonance or to the waves NOT at resonance?
I.e. if the effect is due to the standing waves, then it must hold for the acoustic case as well, right?
We'd have a semi-decidable situation: if the string shows NO effect, then we do know that standing waves aren't involved (because they must behave the same in the frustum). If the string does show an effect however, we don't know if the experimental result would be valid for the frustum because the string does not really fully model the frustum.

It strikes me that a string with variable thickness is easier to manufacture and much safer to use than DIY cavities and magnetrons...
... unless one manages to strangle themselves with the string, but I think it's unlikely. :D

Quote
The only way these things will work is to interact with an outside environment.
...
So heat and poor conductivity allow flux to escape (tunnel) through the copper. I've also found a mechanism to boost the force many times over that of a photon rocket, such that this little bit of energy that escapes may in fact be enough to cause the observed thrust.

More when I finish the paper...
Todd

Looking forward to it.

Offline wallofwolfstreet

  • Full Member
  • *
  • Posts: 165
  • Liked: 169
  • Likes Given: 436
I am not sure if the attached has been covered on here before but it states "EmDrive Licence: 10 year exclusive master licence £100,000,000 comprised of
2 years development to Flight Qualified status @ £10m per year pro rata, plus
consultancy from Roger Shawyer to divest expertise.
Break clause at 2 years, if project fails to achieve FQ status all rights revert to SPR.
A further 3 year exclusive use of EmDrive @ £10m per annum.
After 3 years of exclusive use, master licensee is required to sub licence technology on
similar terms, if requested, to third parties.
For 10 years, royalties of £150k per space vehicle using EmDrive (equivalent to 10% of
the saving on build cost).
After 10 years, master licensee has first right of refusal on renewing master licence"


I know this possibly quite old but may be of interest.

Mike.

Wow Mike, great find.  How did you come across this if you don't mind me asking?  Do you know what year was this made so we can verify the accuracy of the financial statements?

I want to address this quote first:

Quote
Philip Owen and Brian Milnes have been retained to negotiate the sale of a licence to
develop and use EmDrive technology. They are approaching the European and American
markets and the Chinese and Oceanic markets respectively.

As has been discussed by Rodal and myself, this statement makes no sense.  If SPR truly has only UK patents, then they have no license to sell in any market outside of the UK.  Very strange. 

Now we come to this quote:

Quote
The company has been funded with the following:
Funds                                 Pounds
Director's Loans                   132,000
DTI awards                          126,000
External Investor                 250,000
           Total              508,000

The current remaining working capital is around 100,000 pounds and the current cash burn rate is 7,000 per month.

Hmmmm.  It looks likes this document must have been made before the demonstrator engine was completed, because they also write:

 
Quote
...a Demonstration Model which is on schedule.

Suffice to say, their financial picture is not so rosy anymore.  I have attached the last three years of financial returns (2012-2014).  I am interested in examining all of the returns since SPR was founded in 2000, and see if their balance sheet ever looked like what they claim it is in this document.  I will report the results here.  To summarize some recent annual returns, where brackets imply negative net assets (ie. they owe more than they own):

Year                               2011             2012           2013             2014
Net Assets (liabilities)      (222,634)     (237,035)    (236,247)     (234,768)

Here is the link to all the filing history if anyone else is interested. 
« Last Edit: 06/26/2015 05:35 PM by wallofwolfstreet »

Offline Rodal

  • Senior Member
  • *****
  • Posts: 5845
  • USA
  • Liked: 5925
  • Likes Given: 5269
I found information about the original paper for Harminv, unfortuantely it is still behind a paywall. Here is the abstract.

Quote
Article
Harmonic inversion of time signals and its applications

    Vladimir A. Mandelshtam
    Vladimir A. Mandelshtam
    Howard S Taylor
    Howard S Taylor

Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Ángeles, California, United States
The Journal of Chemical Physics (Impact Factor: 3.12). 11/1997; 107(17):6756-6769. DOI: 10.1063/1.475324

ABSTRACT New methods of high resolution spectral analysis of short time signals are presented. These methods utilize the filter-diagonalization approach of Wall and Neuhauser [J. Chem. Phys. 102, 8011 (1995)] that extracts the complex frequencies ωk and amplitudes dk from a signal C(t) = ∑kdke−itωk in a small frequency interval by recasting the harmonic inversion problem as the one of a small matrix diagonalization. The present methods are rigorously adapted to the conventional case of the signal available on a sparse equidistant time grid and use a more efficient boxlike filter. Various applications are discussed, such as iterative diagonalization of large Hamiltonian matrices for calculating bound and resonance states, scattering calculations in the presence of narrow resonances, etc. For the scattering problem the harmonic inversion is directly applied to the signal cn = (χf,Tn(Ĥ)χi), generated by the dynamical system governed by a modified Chebyshev recursion, avoiding the usual recasting the problem to the time domain. Some challenging numerical examples are presented. The general filter-diagonalization method is shown to be stable and efficient for the extraction of thousands of complex frequencies ωk and amplitudes dk from a signal. When the model signal is “spoiled” by a moderate amount of an additive Gaussian noise the obtained spectral estimate is still superior to the conventional Fourier spectrum.

Of course for my purposes within Meep, Gaussian noise is added. Harminv runs for an infinite time when I try to use it without noise. And as mentioned previously the narrower the noise bandwidth the longer the run time.

It does appear, not suprisingly, as though the authors are quite proud of the technique.

Instead of using a frequency domain solver, you  can simply run an equivalent time domain simulation with a continuous wave source, time-stepping until all transient effects from the RF source turn-on have disappeared,  and you have reached steady state oscillation.  Then, to find out the frequency, just plot the electromagnetic fields vs. time and determine the period of the resulting time variation.  Alternatively, you could run a FFT of the response to determine the frequency of the response.

Offline rfmwguy

  • EmDrive Builder (retired)
  • Senior Member
  • *****
  • Posts: 2165
  • Liked: 2681
  • Likes Given: 1124

I saw that in your information. I used traveller's spreadsheet, which is the only working spreadsheet publicly released, (many thanks Mr T.) and it came up with 185 mg of gram-force with a Q of 50K. Not expecting to see that type of Q, I scaled it back to 10K. Plug some numbers into the spreadsheet and see where gram force comes out. Your numbers would be far too small for EMDIYers to validate. Let me know.

That is the problem I have been having. My calculated values, by using experimental data found on the emdrive wiki, are far to small to be measured by the EMDIYer. So, I am a bit stuck on what to expect.

I don't have that kind of space to create what you have, so I have to figure out a smaller way of testing this thing.

If I achieve null results using the shawer inspired spreadsheet, then I would conclude his position is irrelevant. Reason I chose to follow it was its the only public tool I am aware of and its within a diyers measurement capability. Should nasa cough up a designers tool, which I highly doubt, I would consider it provided it doesn't require NIST to test the results.
But then, to be consistent with Shawyer, you have to use his mode shapes, Shawyer uses transverse ELECTRIC TE01 modes, just like Yang.  So you should choose the dimensions that give TE013 at 2.45GHz instead of the dimensions that give the transverse magnetic TM212 mode (used by NASA) at 2.45 GHz.

////////////////////////////////

bigDiameter = 11.01 inches;
smallDiameter = 6.25 inches;
axialLength = 10.2 inches;  NOTICE 10.2 inches -- in this case

with FLAT ENDs with a TRANSVERSE ELECTRIC MODE.  It resonates at 2.45044 GHz with TE013



////////////////////////////////

It would be inconsistent for you to use the  dimensions that give the transverse magnetic TM212 mode (used by NASA) at 2.45 GHz

@rfmwguy,

Please also keep in mind that to achieve the projected Q=50000 would likely require the use of spherically curved end plates.  (unless I misunderstood TheTraveller's description)

The use of flat end plates will result in a much smaller Q.  If I'm reading the emdrive.wiki correctly, I believe Shawyer's early attempt using flat end plates had a reported Q=5900.  I can't remember if the Q=5900 was with a tunable end plate, or if Q=45000 was the tunable end plate.

http://emdrive.wiki/Experimental_Results#cite_ref-Shawyer_Demonstrator_7-0
http://emdrive.wiki/Experimental_Results#cite_note-Shawyer_Demonstrator-7

In either case, I would suggest that anticipating a Q=10000 for your build is a bit....  optimistic.   :-[

Thanks...quite confusing, I must admit in the early stages of this project...9.0 vs 10.2"L. Suppose the logical way to go is 10.2 since it will be far easier to reduce length than to add it. Rodal says 10.2, Aero sees resonance at 9.0. Dielectric or no dielectric? My instincts tell me 9.0L with dielectric is equal to 10.2L without, or thereabouts.

Dielectrics decrease size and lower Q in my experience, which I want to keep as high as possible to avoid wasted energy in the forms of standing waves and heat (small as it may be @8W). Dielectrics add another variable, potential contamination in the form of outgassing at higher temperatures.

One variable I am interested in besides the copper is graphene film on endplates: http://arxiv.org/ftp/arxiv/papers/1210/1210.3444.pdf

Offline Rodal

  • Senior Member
  • *****
  • Posts: 5845
  • USA
  • Liked: 5925
  • Likes Given: 5269
...
Quote
Philip Owen and Brian Milnes have been retained to negotiate the sale of a licence to
develop and use EmDrive technology. They are approaching the European and American
markets and the Chinese and Oceanic markets respectively.

As has been discussed by Rodal and myself, this statement makes no sense.  If SPR truly has only UK patents, then they have no license to sell in any market outside of the UK.  Very strange.  ...
I have been involved in License Negotiation and License Renewal for technologies were NO patents are involved, but instead what is involved are trade secrets.  This would not be unusual, and it is actually quite prevalent for technology involving manufacturing technology (as opposed to design technology).  While for design technology it is always a better idea to patent (because obviously a design is apparent and obvious to anybody buying or seeing the product), that is not the case for manufacturing technology.  Manufacturing is only known to people involved in manufacturing and not to the customer.  Hence it is often better to keep such manufacturing technology as a trade secret, because although Patents expire, trade secrets have no expiration.  Also it is very difficult, onerous, expensive, almost impossible to police violation of manufacturing patents. So it would be difficult to enforce such manufacturing patents.

However, a conscious effort has to be made to keep such trade secret know-how truly secret.  If the "secret" gets out due to lack of proper care, one has lost all recourse (unless the trade secret was misappropriated).

The problem with contemplating such a license for the EM Drive, is that to my knowledge, there is no "there" there.  The licensing agreements involving royalties I was familiar with, involved successful products in the marketplace that were bringing in reall $$$ in sales and profits.  Here with the EM Drive we have no sales, no markets, and it is very controversial whether there is even thrust produced by the EM Drive.
« Last Edit: 06/26/2015 06:13 PM by Rodal »

Offline Rodal

  • Senior Member
  • *****
  • Posts: 5845
  • USA
  • Liked: 5925
  • Likes Given: 5269
...

Thanks...quite confusing, I must admit in the early stages of this project...9.0 vs 10.2"L. Suppose the logical way to go is 10.2 since it will be far easier to reduce length than to add it. Rodal says 10.2, Aero sees resonance at 9.0. ...
Well, my reading is that @aero is not confused on this, as he (apparently, from his last message) understood that I had showed you that there is resonance at 9.0 inches and there is resonance at 10.2 inches.  So I don't understand why you state <<Rodal says 10.2, Aero sees resonance at 9.0>>  ???

The correct statement should read instead:

<<Rodal states resonance at L=9.0 inches and at L=10.2 inches, Aero sees resonance at L=9.0 inches and aero has not yet run L=10.2 inches>>

As far as I know @aero HarmInv has big issues with convergence, he has to add noise to get convergence in a finite time, and has to input a frequency very close to the answer to get an answer.  So he has to know the answer in order to get an answer.  And as far as I know he hasn't tried 10.2 inches yet, and he doesn't know what mode shape was his resonance at 9.0 inches. And to get resonance at 9.0 inches length, he had to input the same frequency and dimensions that I used to get resonance at 9.0 inches.  So where is the confusion?

To clarify @aero's result we must wait until he runs some more runs, so that he can see what mode shape he converged to, and to see what he gets with L=10.2 inches. 
« Last Edit: 06/26/2015 06:04 PM by Rodal »

Offline Star One

  • Senior Member
  • *****
  • Posts: 8020
  • UK
  • Liked: 1281
  • Likes Given: 168

...
Quote
Philip Owen and Brian Milnes have been retained to negotiate the sale of a licence to
develop and use EmDrive technology. They are approaching the European and American
markets and the Chinese and Oceanic markets respectively.

As has been discussed by Rodal and myself, this statement makes no sense.  If SPR truly has only UK patents, then they have no license to sell in any market outside of the UK.  Very strange.  ...
I have been involved in License Negotiation and License Renewal for technologies were NO patents are involved, but instead what is involved are trade secrets.  This would not be unusual, and it is actually quite prevalent for technology involving manufacturing technology (as opposed to design technology).  While for design technology it is always a better idea to patent (because obviously a design is apparent and obvious to anybody buying or seeing the product), that is not the case for manufacturing technology.  Manufacturing is only known to people involved in manufacturing and not to the customer.  Hence it is often better to keep such manufacturing technology as a trade secret, because although Patents expire, trade secrets have no expiration.  Also it is very difficult, onerous, expensive, almost impossible to police violation of manufacturing patents. So it would be difficult to enforce such manufacturing patents.

However, a conscious effort has to be made to keep such trade secret know-how truly secret.  If the "secret" gets out due to lack of proper care, one has lost all recourse (unless the trade secret was misappropriated).

The problem with contemplating such a license for the EM Drive, is that to my knowledge, there is no "there" there.  The licensing agreements involving royalties I was familiar with, involved successful products in the marketplace that were bringing in reall $$$ in sales and profits.  Here with the EM Drive we have no sales, no markets, and it is very controversial whether there is even thrust produced by the EM Drive.

Actually, some scientists, engineers and managers in aerospace have interpreted the NASA results as an outright nullification of Shawyer's and Yang's claims, because NASA obtained zero, nada, zilch thrust response when using no dielectric inserts, and because when using dielectric inserts (which Shawyer claims is not using any longer), NASA obtained force/PowerInput orders of magnitude smaller than what Shawyer is claiming.

Does it really matter how others have interpreted their results at this stage, surly all that matters is what EW make of them. Of which you, me and no one else outside of EW know the current position so I don't see that as a relevant point at this time.

Offline Rodal

  • Senior Member
  • *****
  • Posts: 5845
  • USA
  • Liked: 5925
  • Likes Given: 5269
...Does it really matter how others have interpreted their results at this stage, surly all that matters is what EW make of them. Of which you, me and no one else outside of EW know the current position so I don't see that as a relevant point at this time.
It most certainly matters, for what we are discussing here: Licensing Agreements.  Who is going to pay 100 million British Pounds Licensing Agreement for a technology that has only 3 British Patents, no Patents awarded outside the UK, and for which it now may be interpreted that NASA has nullified with their experiments???

The issue regarding Licensing Royalties  is not how "we" interpret anything, the issue is who is going to be willing to pay Royalties for something that is even controversial whether it works or not at this point in time, much less as to whether one is paying Royalties for something that has no sales yet and has not been demonstrated in the marketplace.

Licensing agreements and Royalties certainly don't easily work that way in the business world I live in.  It is much tougher than that.
« Last Edit: 06/26/2015 06:32 PM by Rodal »

Tags: