Author Topic: EM Drive Developments - related to space flight applications - Thread 2  (Read 2105129 times)

Offline matthewpapa

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Would one practical use, if they do work, be a satellite with clusters of EM drives on different axis used for station keeping?

Of how much practical use would they be in reality for interplanetary probes.

That, or have it use a gyroscope.
Since no propellant is emitted, this should be feasible I think. Could be really cool!

Could be great for interplanetary probes since they can just go from destination to destination. Worst case it has to come back to earth every once in a while for new fuel rods, but you essentially have unlimited delta-v. As long as the force of your EM drive output force is greater than any nearby gravity well you arent orbiting
« Last Edit: 02/19/2015 07:40 PM by matthewpapa »

Offline Rodal

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A question... is the Q-Thruster that was being worked by EagleWorks Lab similar to the EM Drive they tested? Are them completely different things with different principles? I have the vague notion of seeing a photo of it long ago (while the main subject of the article was in fact Dr White's Warp Drive experiments) and I donīt remember it having a cone similar to Shawyer's EM Drive, so I guess they are totally different principles? I wonder if the former is still being pursued? If it is "considered" an EM Drive? Maybe Paul March can clear this up (if noone else knows the answer)?

It appears that when METs, MLT, SFEs, Cannaes and Emdrives go through the doors of Eagleworks, they get rolled into the QVPT conjecture. In reality, they come from different sources, different inventors with different theories of operation. Dr. White, IMHO is right to try and unify these different types of "thrusters" under the same paradigm. I think they are all unified too under the same interaction, maybe not QVPT per se, but they share the QV as a common means of interaction.
https://www.linkedin.com/pub/hector-serrano/29/69b/9a5
https://xa.yimg.com/kq/groups/86787010/513081407/name/Eagleworks+Newsletter+2013.pdf
http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20110023492.pdf
http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20140009930.pdf

OK with Eagleworks doing that, but for this thread let's continue to keep the focus on EM Drive Developments - related to space flight applications, as per SpaceFLight Forum Admin., with EM Drive defined as microwave cavity resonators , of converging focusing type, as the Cannae pillbox and the truncated cones with flat ends at NASA, Shawyer (UK) and Juan Yang (China) or Shawyer's superconducting EM Drive with spherical ends.

Discussions of piezoelectric MET can be conducted in this thread:  http://forum.nasaspaceflight.com/index.php?topic=31037.460

so as to avoid getting into the problems suffered in Thread 1.
« Last Edit: 02/19/2015 09:53 PM by Rodal »

Offline tchernik

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Shawyer has seemed convinced that this drive is able to replace commercial airliner engines etc. Obviously as he is the main proponent of the drive so this might be taken with a pinch of salt or two but if the drive is proven to be real he definitely seems to be ahead of the curve with the technology.

And if we believe the Chinese results, the tech is squarely at the "useful for probes and satellite station-keeping/ re-positoning" phase now.

The current validation work at NASA, besides the potential synergies with other similar efforts, and even the talks of smart people from Internet forums (not me, I'm just happy to be here), should allow interested and currently acting people to perceive potential vectors in the space of improvement, resulting in increases of  the much sought Newtons per Watt ratio.

That's of the utmost importance, because the higher such ratio, the easier to show this phenomenon's existence without the shadow of a doubt.

Offline Mulletron

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I guess not everyone realizes that a resonant cavity can be represented as an LC circuit. They're all the same thing.

Challenge your preconceptions, or they will challenge you. - Velik

Offline Rodal

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I guess not everyone realizes that a resonant cavity can be represented as an LC circuit. They're all the same thing.


It can be represented by a simple LC circuit only for simple uniform cavities, with uniform cross-sections, as for example the rectangular cross section cavity or the cylindrical cavity. 

The truncated cone (frustum) shape used by NASA, Shawyer in the UK and Prof. Juan Yang in China displays degenerate modes that go from resonant to evanescent, and it displays modes that do not conform to the same TEmnp or TMmnp designation as in cylindrical cavities.  Actually in reviewing the mode shapes assigned in the COMSOL study for NASA I am now reviewing some interesting cases (the frequencies and images computed by COMSOL are excellent, but the designation of some of the modes is not straightforward, as the NASA engineer realized when designating some of the modes as "X").

The truncated cone and the Cannae pillbox effect also display very interesting attenuation and focusing effects not present in the uniform-cross section cavities.  These focusing effects may be very important for the EM Drive.
« Last Edit: 02/19/2015 08:36 PM by Rodal »


Offline Notsosureofit

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I guess not everyone realizes that a resonant cavity can be represented as an LC circuit. They're all the same thing.


It can be represented by a simple LC circuit only for simple uniform cavities, with uniform cross-sections, as for example the rectangular cross section cavity or the cylindrical cavity. 

The truncated cone (frustum) shape used by NASA, Shawyer in the UK and Prof. Juan Yang in China displays degenerate modes that go from resonant to evanescent, and it displays modes that do not conform to the same TEmnp or TMmnp designation as in cylindrical cavities.  Actually in reviewing the mode shapes assigned in the COMSOL study for NASA I am now reviewing some interesting cases (the frequencies and images computed by COMSOL are excellent, but the designation of some of the modes is not straightforward, as the NASA engineer realized when designating some of the modes as "X").

There is some flexibility.  I remember working on delay lines w/ parameters varying w/ length.

That was odd stuff, I wonder if it can make a resonant circuit that way?
« Last Edit: 02/19/2015 08:40 PM by Notsosureofit »

Offline Rodal

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I guess not everyone realizes that a resonant cavity can be represented as an LC circuit. They're all the same thing.


It can be represented by a simple LC circuit only for simple uniform cavities, with uniform cross-sections, as for example the rectangular cross section cavity or the cylindrical cavity. 

The truncated cone (frustum) shape used by NASA, Shawyer in the UK and Prof. Juan Yang in China displays degenerate modes that go from resonant to evanescent, and it displays modes that do not conform to the same TEmnp or TMmnp designation as in cylindrical cavities.  Actually in reviewing the mode shapes assigned in the COMSOL study for NASA I am now reviewing some interesting cases (the frequencies and images computed by COMSOL are excellent, but the designation of some of the modes is not straightforward, as the NASA engineer realized when designating some of the modes as "X").

There is some flexibility.  I remember working on delay lines w/ parameters varying w/ length.

That was odd stuff, I wonder if it can make a resonant circuit that way?

I agree, that's why I wrote "It can be represented by a simple LC circuit only".  Yes, with a circuit complicated enough we could probably simulate most electromagnetic wave phenomena, just like the few analog computers that still were being used at MIT Labs in the early 1970's to solve differential equations.  I remember those  :).   Reconfiguring the analog computer to solve a different equation required actual handwork unlike just writing software for digital computers :-)

« Last Edit: 02/19/2015 08:53 PM by Rodal »

Offline Notsosureofit

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I guess not everyone realizes that a resonant cavity can be represented as an LC circuit. They're all the same thing.


It can be represented by a simple LC circuit only for simple uniform cavities, with uniform cross-sections, as for example the rectangular cross section cavity or the cylindrical cavity. 

The truncated cone (frustum) shape used by NASA, Shawyer in the UK and Prof. Juan Yang in China displays degenerate modes that go from resonant to evanescent, and it displays modes that do not conform to the same TEmnp or TMmnp designation as in cylindrical cavities.  Actually in reviewing the mode shapes assigned in the COMSOL study for NASA I am now reviewing some interesting cases (the frequencies and images computed by COMSOL are excellent, but the designation of some of the modes is not straightforward, as the NASA engineer realized when designating some of the modes as "X").

There is some flexibility.  I remember working on delay lines w/ parameters varying w/ length.

That was odd stuff, I wonder if it can make a resonant circuit that way?

I agree, that's why I wrote "It can be represented by a simple LC circuit only".  Yes, with a circuit complicated enough we could probably simulate most electromagnetic wave phenomena, just like the few analog computers that still were being used at MIT Draper Labs in the early 1970's to solve differential equations.  I remember those  :).   Reconfiguring the analog computer to solve a different equation required actual handwork unlike just writing software for digital computers :-)

I guess I can't stop thinking about the 1/ f^3 in the thrust equation.

Dual 12at7's I think....
« Last Edit: 02/19/2015 08:54 PM by Notsosureofit »

Offline Rodal

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It can be represented by a simple LC circuit only for simple uniform cavities, with uniform cross-sections, as for example the rectangular cross section cavity or the cylindrical cavity. 

The truncated cone (frustum) shape used by NASA, Shawyer in the UK and Prof. Juan Yang in China displays degenerate modes that go from resonant to evanescent, and it displays modes that do not conform to the same TEmnp or TMmnp designation as in cylindrical cavities.  Actually in reviewing the mode shapes assigned in the COMSOL study for NASA I am now reviewing some interesting cases (the frequencies and images computed by COMSOL are excellent, but the designation of some of the modes is not straightforward, as the NASA engineer realized when designating some of the modes as "X").

There is some flexibility.  I remember working on delay lines w/ parameters varying w/ length.

That was odd stuff, I wonder if it can make a resonant circuit that way?

I agree, that's why I wrote "It can be represented by a simple LC circuit only".  Yes, with a circuit complicated enough we could probably simulate most electromagnetic wave phenomena, just like the few analog computers that still were being used at MIT Draper Labs in the early 1970's to solve differential equations.  I remember those  :).   Reconfiguring the analog computer to solve a different equation required actual handwork unlike just writing software for digital computers :-)

I guess I can't stop thinking about the 1/ f^3 in the thrust equation.

Dual 12at7's I think....


gives thrust per photon:

T = (h/(2*L*f))*(c/(2*pi))^2*X^2*((1/Rs^2)-(1/Rb^2))

If the number of photons is (P/hf)*(Q/2*pi) then:

NT = P*Q*(1/(4*pi*L*f^3))*(c/(2*pi))^2*X^2*((1/Rs^2)-(1/Rb^2))
« Last Edit: 02/19/2015 09:04 PM by Rodal »

Offline Rodal

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...

I guess I can't stop thinking about the 1/ f^3 in the thrust equation.

Dual 12at7's I think....


gives thrust per photon:

T = (h/(2*L*f))*(c/(2*pi))^2*X^2*((1/Rs^2)-(1/Rb^2))

If the number of photons is (P/hf)*(Q/2*pi) then:

NT = P*Q*(1/(4*pi*L*f^3))*(c/(2*pi))^2*X^2*((1/Rs^2)-(1/Rb^2))

If the thrust really decreases as the cube of the frequency...wouldn't you get much less thrust operating your experiment in the X band? ( 8.0 to 12.0 GHz  instead of 2 GHz implies 64 to 216 times less thrust, of course that's with everything else being the same which is not going to be...)
« Last Edit: 02/19/2015 09:03 PM by Rodal »

Offline Notsosureofit

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...

I guess I can't stop thinking about the 1/ f^3 in the thrust equation.

Dual 12at7's I think....


gives thrust per photon:

T = (h/(2*L*f))*(c/(2*pi))^2*X^2*((1/Rs^2)-(1/Rb^2))

If the number of photons is (P/hf)*(Q/2*pi) then:

NT = P*Q*(1/(4*pi*L*f^3))*(c/(2*pi))^2*X^2*((1/Rs^2)-(1/Rb^2))

If the thrust really decreases as the cube of the frequency...wouldn't you get much less thrust operating your experiment in the X band? ( 8.0 to 12.0 GHz  instead of 2 GHz implies 64 to 216 times less thrust, of course that's with everything else being the same which is not going to be...)

L goes down as well, but then the x-band sources are usually not as efficient either. How much more sensitive is the Cavendish setup?

Offline Rodal

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...

I guess I can't stop thinking about the 1/ f^3 in the thrust equation.

Dual 12at7's I think....


gives thrust per photon:

T = (h/(2*L*f))*(c/(2*pi))^2*X^2*((1/Rs^2)-(1/Rb^2))

If the number of photons is (P/hf)*(Q/2*pi) then:

NT = P*Q*(1/(4*pi*L*f^3))*(c/(2*pi))^2*X^2*((1/Rs^2)-(1/Rb^2))

If the thrust really decreases as the cube of the frequency...wouldn't you get much less thrust operating your experiment in the X band? ( 8.0 to 12.0 GHz  instead of 2 GHz implies 64 to 216 times less thrust, of course that's with everything else being the same which is not going to be...)

L goes down as well, but then the x-band sources are usually not as efficient either. How much more sensitive is the Cavendish setup?

0.174 uN according to Wikipedia:

<<Cavendish's equipment was remarkably sensitive for its time.[9] The force involved in twisting the torsion balance was very small, 1.74 x 10–7 N,[11] about 1/50,000,000 of the weight of the small balls[12] or roughly the weight of a large grain of sand.[13] To prevent air currents and temperature changes from interfering with the measurements, Cavendish placed the entire apparatus in a wooden box about 2 feet (0.61 m) thick, 10 feet (3.0 m) tall, and 10 feet (3.0 m) wide, all in a closed shed on his estate. Through two holes in the walls of the shed, Cavendish used telescopes to observe the movement of the torsion balance's horizontal rod. The motion of the rod was only about 0.16 inches (4.1 mm).[14] Cavendish was able to measure this small deflection to an accuracy of better than one hundredth of an inch using vernier scales on the ends of the rod>>
« Last Edit: 02/19/2015 09:56 PM by Rodal »

Offline Flyby

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Not really my expertise field.............
Welcome to the group. This is very much a multidisciplinary effort. What are you good at?
Well, mmm...  of formation, I'm an architect, but always had a strong interest in what happening on the nuclear science field and spaceflight development. But the last 25 years I've specialized in 3D visualizations, 3Dmodeling and 3Dprinting (8 years).
I fear that on the real hard science level, i might have little to nothing to add to the high standards here, but if there is anything I can do as far as visual communication goes, I might be of help or assistance, if needed...
I also have considerable experience modeling for and working with a powder 3Dprinter, but I suppose NASA has much more advanced systems to their disposal.
And  ofc, If any of the DIY builders here would require assistance in building 3Dmodels for 3dprinting i'll gladly assist.

Offline Rodal

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Not really my expertise field.............
Welcome to the group. This is very much a multidisciplinary effort. What are you good at?
Well, mmm...  of formation, I'm an architect, but always had a strong interest in what happening on the nuclear science field and spaceflight development. But the last 25 years I've specialized in 3D visualizations, 3Dmodeling and 3Dprinting (8 years).
I fear that on the real hard science level, i might have little to nothing to add to the high standards here, but if there is anything I can do as far as visual communication goes, I might be of help or assistance, if needed...
I also have considerable experience modeling for and working with a powder 3Dprinter, but I suppose NASA has much more advanced systems to their disposal.
And  ofc, If any of the DIY builders here would require assistance in building 3Dmodels for 3dprinting i'll gladly assist.
Great  :), we needed (and we still need) help with estimating dimensions of test articles from photographs that often have parallax problems and undimensioned drawings (technical authors often fail to detail the dimensions in their technical papers).   We are very fortunate that Paul March was kind enough to supply the dimensions of the NASA EM Drive truncated cone, but we will need help to estimate other devices from the UK, China and the USA.  Still @aero and @Mulletron did a fantastic job in estimating the NASA EM Drive dimensions just from the photographs.

Perhaps when we are ready to calculate expressions again for other devices, you can help us (at that time in the future).   :)

Thanks

Offline Flyby

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Shawyer has seemed convinced that this drive is able to replace commercial airliner engines etc. Obviously as he is the main proponent of the drive so this might be taken with a pinch of salt or two but if the drive is proven to be real he definitely seems to be ahead of the curve with the technology.

Shawyer has yet to prove that the performance of his "engine" scales linear with a dramatically increased Q.

Personally, I have my doubts his supercooled 2nd generation engine will scale to such a point that it creates 1ton of thrust from 1kW, as he claims...'sounds too good to be true...
But.. only time will tell, i suppose...



Offline Rodal

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Shawyer has yet to prove that the performance of his "engine" scales linear with a dramatically increased Q.

..

Good point, on the other hand all theoretical formulas so far scale linearly with Q:

@Notsosureoit:  http://forum.nasaspaceflight.com/index.php?topic=36313.msg1332746#msg1332746

McCulloch MiHsC :  http://physicsfromtheedge.blogspot.com/2015/02/mihsc-vs-emdrive-data-3d.html

Shawyer:   http://www.emdrive.com/IAC-08-C4-4-7.pdf

Notice particularly the table in  McCulloch MiHsC :  http://physicsfromtheedge.blogspot.com/2015/02/mihsc-vs-emdrive-data-3d.html

There is a huge range of Q from Q= 5900 all the way to Cannae's Superconducting which has Q=11000000 
that is a range differing by a factor of almost 2000 from Min to Max


The big problem is delivering a high enough thrust/InputPower, for the reasons we have been discussing (starting with whether the results are an artifact, to thermal distortion, difficulty with keeping the EM Drive at the Q peak, etc etc).  We will not know until experiments demonstrate it.
« Last Edit: 02/19/2015 11:25 PM by Rodal »

Offline Notsosureofit

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Shawyer has yet to prove that the performance of his "engine" scales linear with a dramatically increased Q.

..

Good point, on the other hand all theoretical formulas so far scale linearly with Q:

@Notsosureoit:  http://forum.nasaspaceflight.com/index.php?topic=36313.msg1332746#msg1332746

....

I keep checking back and ..... there's another bloody typo !     N=P*Q/(2*pi*h*f^2)         [ f^2 NOT f ]

If I could type I'd be dangerous !

Going back and scaling term by term it looks like (at constant power) only Q and X, everything else is  a wash between distances and freq.
« Last Edit: 02/20/2015 12:22 AM by Notsosureofit »

Offline Rodal

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Shawyer has yet to prove that the performance of his "engine" scales linear with a dramatically increased Q.

..

Good point, on the other hand all theoretical formulas so far scale linearly with Q:

@Notsosureoit:  http://forum.nasaspaceflight.com/index.php?topic=36313.msg1332746#msg1332746

....

I keep checking back and ..... there's another bloody typo !     N=P*Q/(2*pi*h*f^2)         [ f^2 NOT f ]

If I could type I'd be dangerous !

Going back and scaling term by term it looks like (at constant power) only Q and X, everything else is  a wash between distances and freq.

That makes perfect sense because both Q and X are the only non-dimensional parameters in your equation.

Actually, now that you mention it we should non-dimensionalize all the equations (yours, Shawyer's and McCulloch's) in order to express them in term of non-dimensional parameters (Buckingham Pi theorem:   if there is a physically meaningful equation involving a certain number, n, of physical variables, and k is the rank of the dimensional matrix, then the original expression is equivalent to an equation involving a set of p = n − k  dimensionless parameters)
« Last Edit: 02/20/2015 12:50 AM by Rodal »

Offline Star-Drive

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those mission parameters presupposed electrical power from solar panels? I guess that some good fission or fusion reactors (whenever fusion is available) would allow the addition of even more EM Drives and cut that mission time several times.

Aceshigh:

When it comes to manned solar electric propulsion missions, the largest to date proposed photovoltaic arrays for a human crewed missions are in the 300 kilowatt electric (kW-e) power range.  However most of the Q-Thruster solar system based mission analysis we did last year assumed using a U235 fission based reactor with a closed-cycle brayton or rankine thermal to electrical power conversion cycle system in the 1.0-to-2.0 Megawatt electric (MW-e) class output with at least a 10 year lifetime.  Now it's true that such a space based nuclear power reactor system has never been fielded, but that was due to a lack of a funded mission for same like sending humans to Mars, but more importantly, the lack of the political will to do so.  However building such a space-based closed cycle electrical power reactor is technologically feasible and has been since the 1980s. 

Now like all naval  propulsion system, once you've established the viability of a propulsion technique like the EM-Drive, and have an urgent need to do so, what comes next is developing the long lead items needed to power it.  And all these electric space propulsion concepts for deep-space human missions, be they conventional ion, Hall or VASMIR type plasma rocket thrusters, or Q-thruster like space drives, go begging for an already developed nuclear power plant that is sized from 1.0 MWe up to 100 MWe output dependent on the mission scenario.  I know that this sounds like a lot of power to the space community, but when it's compared to what the US Navy already builds for its nuclear submarine fleet like its "Boomer' Ohio class ICBM vehicles, which sport the 220 MW-thermal (MW-t) S8G reactor that fits in a 42 foot diameter by 55 feet long container and lasts for up to 30 years between refueling, its not a lot to ask technically if we just had the real need to do so.  And that will always be a political and business decision, not a technical one.

Best, Paul M.

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