Author Topic: EM Drive Developments - related to space flight applications - Thread 2  (Read 2105862 times)

Offline Rodal

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In this report http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20110023492.pdf NASA's Dr. White wrote of his continuing "dialogue with the (International Space Station) ISS national labs office for an on orbit DTO (On Orbit Detailed Test Objectives)" of the EM Drive (which he calls "Q-Thruster"):


The "Q-Thruster" in this case appears to be a Woodward/ME device.

Quote
The "Q-Thruster" in this case appears to be a Woodward/ME device.   

Yes.  No.  Sort of.
....

1) The example of "Q-Thruster" pictured in the report is what's called by Woodward followers a "Mach-Lorentz thruster (MLT)".  As such, it is not a Woodward Mach Effect (Piezoelectric) device.  The  Mach-Lorentz thruster (MLT) uses a charging capacitor embedded in a magnetic field created by a magnetic coil. It is claimed that a Lorentz force, cross product between the electric field and the magnetic field, appears and acts upon the ions inside the capacitor dielectric. In such electromagnetic experiments, the power can be applied at frequencies of several megahertz, unlike piezoelectric PZT stack actuators where frequency is presently limited to tens of kilohertz.  This kind of Mach Lorentz thruster (MLT) was nullified by the experiments of Brito, Marini and Galian (who used a classic Cavendish type pendulum where all the power supply was self-contained with the MLT device).  The nullifying experiments of Brito Marini and Galian (http://enu.kz/repository/2009/AIAA-2009-5070.pdf) where repeated and published in a peer-reviewed AIAA journal (Journal of Propulsion and Power) (http://arc.aiaa.org/doi/abs/10.2514/1.46541?journalCode=jpp).  Woodward has instead concentrated on the Mach Effect (Piezoelectric) thruster.

2) To concentrate on spaceflight applications (the subject of this thread) it is of paramount importance the amount of power required to produce a given level of thrust. Notice that the force per power input reported by Woodward's Mach Effect thruster in their latest reported experiments (Fearn, Zachar, Woodward & Wanser) is several orders of magnitude lower than the "EM drives".  Actually it is barely (3.5 times higher) more than the force per power input of a photon rocket (using a military searchlight as a means of propulsion ! ):

reported measurement ForcePerPowerInput (milliNewtons/kW)

MICROWAVE (* Cannae Superconducting *)             761.9 to 952.4
MICROWAVE (* Prof. Juan Yang et.al. China*)            290
MICROWAVE (* Shawyer Demo *)                               80 to 243
MICROWAVE (* Shawyer Experimental *)                   18.82
MICROWAVE (* Brady c TE mode *)                             21.31
MICROWAVE (* Brady a TM mode*)                               5.396
MICROWAVE (* Brady b TM mode*)                               3.000
PIEZOELECTRIC (*Fearn, Zachar, Woodward & Wanser*) 0.01176

3) To understand what is important for spaceflight applications: how small is the force (for a given power input) produced by Woodward's (Fearn, Zachar, Woodward & Wanser) latest Mach Effect experiments: it takes 80000 times greater power to produce the same level of force with the Woodward's (Fearn, Zachar, Woodward & Wanser) device as the superconducting EM Drive.  Also for spaceflight applications comparison, notice that while Dr. White calculated that it would take 2 MW power input (nuclear power generation) for the microwave EM Drive at 0.4 N/kW missions to Mars and Titan/Enceladus, it would take 68 *(10 ^9) watts (68 Gigawatts) for Woodward's (Fearn, Zachar, Woodward & Wanser) device to produce the same thrust, given its tiny 0.00001176 N/kW thrust/PowerInput. (Fearn, Zachar, Woodward & Wanser device gives just 3.5 times the thrust/powerInput of a very inefficient classical-physics means of propellant-less propulsion: using a military searchlight as a photon-rocket ) . 

4) Thus, it is evident, that for spaceflight applications  (the subject of this thread) we should concentrate on the devices that require orders of magnitude (up to  80000 times) less power to produce a given level of thrust: the microwave EM Drives.

5) Dr. White used the term "Q-thruster" in general for all of these devices (including the MLT Thruster, Boeing's Serrano Effect Device and the microwave EM drives).  See the slide by Dr. White enclosed below.  For the above-pointed (and other) reasons, Dr. White at NASA Eagleworks has moved on and is presently concentrating on Microwave-Cavity Drives, as the reported experimental data shows that they are much more promising for spaceflight applications.  This makes sense.

6) The point is that Dr. White wrote that he has a dialogue with the (International Space Station) ISS national labs office for an on orbit DTO (On Orbit Detailed Test Objectives)" of the EM Drive (which he calls "Q-Thruster") and therefore his plan is to eventually test the EM Drive in the ISS: which would obviously constitute a spaceflight demonstration.

« Last Edit: 01/09/2015 05:10 PM by Rodal »

Offline tchernik

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Great posts by Rodal and Mulletron.

And I concur: the next step is to firmly cement the scientific nature of the mentioned thrusters (them being falsifiable), by providing additional replications and tests. Theories can come later, if empiric evidence is there.

It doesn't matter if H. White's theory is right or wrong, the same as Woodward's (or Shawyer's, which is most likely wrong). What matters is that the phenomena related to those theories would have evidence of being real.

Humanity has used real phenomena nobody can explain for millenia, and this way before even having complete formal descriptions/theories for them. We still do, as we don't know the provenance and nature of inertia and gravity, and they are part of our everyday lives and expected to work for a lot of technology to function as well.
« Last Edit: 01/09/2015 04:22 PM by tchernik »

Offline Star One

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Great posts by Rodal and Mulletron.

And I concur: the next step is to firmly cement the scientific nature of the mentioned thrusters (them being falsifiable), by providing additional replications and tests. Theories can come later, if empiric evidence is there.

It doesn't matter if H. White's theory is right or wrong, the same as Woodward's (or Shawyer's, which is most likely wrong). What matters is that the phenomena related to those theories would have evidence of being real.

Humanity has used real phenomena nobody can explain for millenia, and this way before even having complete formal descriptions/theories for them. We still do, as we don't know the provenance and nature of inertia and gravity, and they are part of our everyday lives and expected to work for a lot of technology to function as well.

All well & good unless it proves through theory they are doing some fundamental damage. Something raised in fiction by a Star Trek: The Next Generation & the use of warp drive damaging the universe.

Offline tchernik

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All well & good unless it proves through theory they are doing some fundamental damage. Something raised in fiction by a Star Trek: The Next Generation & the use of warp drive damaging the universe.

Well, it has happened in the past. For example, that's what happened with those first researching radioactive and nuclear phenomena in general. They first knew they had some new phenomena in their hands and they knew how to produce some of the effects, but they didn't know how bad it was to have it near you. Several people died of radiation poisoning, and some cases even documented by the victim, in a moving display of dedication to science.

These are not precisely universe-destroying dangers per se, but equally life-wrecking stuff.

And we also learned.

Offline Stormbringer

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 :D There is (however tenuously) a potential real world equivalent. collapse of the vacuum potential of the universe from mucking about with high energy collisions, quantum vacuums and warping space. the odds are about 2/3'rds in an infinity-1 gabbillion chance of it. but it could theoretically happen. :)

EDIT:  But then I think the *vacuum* potential is measured in micro-Hoover (TM) units.
« Last Edit: 01/10/2015 12:39 AM by Stormbringer »
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Offline Mulletron

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Big difference between figure 5 here: http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20110023492.pdf (same old Q-thruster paper we've been reading)

and figures 2/3 here: http://www.jhuapl.edu/techdigest/TD/td2804/McNutt.pdf (MPD thrusters/Nuclear power)

The difference between Jupiter transit times is astonishing. Not to mention you don't have to carry aloft ~75 percent of your mass as propellant. Disclaimer though, the empty mass of Jupiter mission spacecraft (fig. 2 McNutt) is ~4081 metric tons (why so massive? anybody know*? This is about half as much as of one of these metal monstrosities http://en.wikipedia.org/wiki/Ticonderoga-class_cruiser), compared to the 90 metric tons (fig. 5 White) (50mT payload,  propulsion mass 20 mT, 2MW power system 20 mT. I'm not sure what the author intended here. I'm assuming a spacecraft with a mass of at least 90 metric tons total though.)

Anybody have any idea how massive this is? http://en.wikipedia.org/wiki/High_beta_fusion_reactor

It would be interesting to put together an imaginary ship using say....a cluster of the Brady c TE mode articles @21.31 milliNewtons/kW + a Lockheed Martin 100MW miracle reactor -reasonable electrical power and RF efficiency losses, to see if anything interesting can be done. Is there even enough information for this to be do-able yet?

Edit: * Found the mass, (McNutt pg. 385) "For the types of systems envisioned in the calculations of Fig. 5, ~1700 t of mass is sufficient to cross from Earth to Neptune in ~2 years (assuming 0.1 kg/kWe and an exhaust speed of 200 km·s−1). The mass of ~420 t is intended to carry food for a crew of six for 5 years, little more shielding than that provided by the structural mass of the ship, and a Boreas-style station that could be used as a science staging base on Triton and left there for any future expeditions."

Seems like the Dr. White example from figure 5 might be a little light.
« Last Edit: 01/10/2015 09:04 PM by Mulletron »
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Offline CW

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Big difference between figure 5 here: http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20110023492.pdf (same old Q-thruster paper we've been reading)

and figures 2/3 here: http://www.jhuapl.edu/techdigest/TD/td2804/McNutt.pdf (MPD thrusters/Nuclear power)

The difference between Jupiter transit times is astonishing. Not to mention you don't have to carry aloft ~75 percent of your mass as propellant. Disclaimer though, the empty mass of Jupiter mission spacecraft (fig. 2 McNutt) is ~4081 metric tons (why so massive? anybody know? This is about half as much as of one of these metal monstrosities http://en.wikipedia.org/wiki/Ticonderoga-class_cruiser), compared to the 90 metric tons (fig. 5 White) (50mT payload,  propulsion mass 20 mT, 2MW power system 20 mT. I'm not sure what the author intended here. I'm assuming a spacecraft with a mass of at least 90 metric tons total though.)

Anybody have any idea how massive this is? http://en.wikipedia.org/wiki/High_beta_fusion_reactor

It would be interesting to put together an imaginary ship using say....a cluster of the Brady c TE mode articles @21.31 milliNewtons/kW + a Lockheed Martin 100MW miracle reactor -reasonable electrical power and RF efficiency losses, to see if anything interesting can be done. Is there even enough information for this to be do-able yet?

As the Lockheed Martin reactor will supposedly fit onto a truck, my guesstimate is 5..10mt with shielding, superconducting magnets and whatnot. If it is a thermal conversion model, then LM will need to use heat exchangers with gas turbines to get the electrical power out (makes it heavier again). My favorite, the direct conversion model with p-B11 fuel, would obviously be more compact. I'm worrying a bit about how to get rid of that immense waste heat in a vacuum, though. The radiators would glow red-hot, I guess. They could also use the photon pressure from the waste heat to accelerate.. .
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Offline Mulletron

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Big difference between figure 5 here: http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20110023492.pdf (same old Q-thruster paper we've been reading)

and figures 2/3 here: http://www.jhuapl.edu/techdigest/TD/td2804/McNutt.pdf (MPD thrusters/Nuclear power)

The difference between Jupiter transit times is astonishing. Not to mention you don't have to carry aloft ~75 percent of your mass as propellant. Disclaimer though, the empty mass of Jupiter mission spacecraft (fig. 2 McNutt) is ~4081 metric tons (why so massive? anybody know? This is about half as much as of one of these metal monstrosities http://en.wikipedia.org/wiki/Ticonderoga-class_cruiser), compared to the 90 metric tons (fig. 5 White) (50mT payload,  propulsion mass 20 mT, 2MW power system 20 mT. I'm not sure what the author intended here. I'm assuming a spacecraft with a mass of at least 90 metric tons total though.)

Anybody have any idea how massive this is? http://en.wikipedia.org/wiki/High_beta_fusion_reactor

It would be interesting to put together an imaginary ship using say....a cluster of the Brady c TE mode articles @21.31 milliNewtons/kW + a Lockheed Martin 100MW miracle reactor -reasonable electrical power and RF efficiency losses, to see if anything interesting can be done. Is there even enough information for this to be do-able yet?

As the Lockheed Martin reactor will supposedly fit onto a truck, my guesstimate is 5..10mt with shielding, superconducting magnets and whatnot. If it is a thermal conversion model, then LM will need to use heat exchangers with gas turbines to get the electrical power out (makes it heavier again). My favorite, the direct conversion model with p-B11 fuel, would obviously be more compact. I'm worrying a bit about how to get rid of that immense waste heat in a vacuum, though. The radiators would glow red-hot, I guess. They could also use the photon pressure from the waste heat to accelerate.. .

Lockheed Martin keeps throwing around that it will fit onto a truck. http://www.lockheedmartin.com/us/products/compact-fusion.html As I suspected, that can be a very wide range of weight.

First depending on where you look, an empty 18 wheeler with trailer weights ~15mT.

I did some digging and I found that the max gross weight of every conex box size is ~30mT. http://en.wikipedia.org/wiki/Intermodal_container#Specifications

If I use the federal interstate gross vehicle weight limits, they are ~36mT. Subtract that ~15mT empty truck weight plus another ton to keep things super simple, you get ~20mT.

So to me, "it fits on a truck" sounds like 20-30mT.

If we want to get ridiculous here though, with a permit, using Florida and Texas as examples, you can haul as much as 78mT and 90mT respectively. http://www.fhwa.dot.gov/reports/tswstudy/Vol2-Chapter2.pdf

Now for perspective, the ISS weights in at 924,739 pounds or ~420mT.
http://www.nasa.gov/mission_pages/station/main/onthestation/facts_and_figures.html#.VLG_FnupjSh
http://www.arianespace.com/news-press-release/2014/7-29-2014-VA219-launch-success.asp
Also Skylab, http://en.wikipedia.org/wiki/Skylab ~77mT.

So that kind of tonnage on orbit isn't out of our reach by any means already. Just launched in stages.

Since I know, and I'm sure many of you have seen as well, reality hardly lives up to expectations, so I'm inclined to, for the purpose of this exercise, make the reactor twice as massive and deliver half the power. So double the Dr. White/"it fits on a truck" 20mT figure and factoring in ~50% DEC, http://en.wikipedia.org/wiki/Direct_energy_conversion, 50MW power. A 40mT/50 MWe power system.

@Rodal, care to throw some math at combining this 40mT/50 MWe power system with one of those thrusters you got the calcs on? Honestly the only numbers I trust are the Brady et al ones, not the inventor's numbers. How much RF can you pump into just one of those Shawyer designs before it starts to melt down? >9000 Watts? What about a hundred of them at once? I estimate they weigh ~10lbs each. It seems ~70% RF amp efficiency is a good round number (http://forum.nasaspaceflight.com/index.php?topic=36313.msg1311433#msg1311433).

Edit:
Um I feel like I screwed this up? The final velocity seems kinda um, large. :o I didn't subtract the Sun pulling on it, but I think something else is wrong.

So throwing around numbers using the ISS as an example (just converted it to an interplanetary spaceship) with a mass of 500mT (420mT original + 40mT 50MWe reactor module add on + 20mT propulsion/aux systems add on + 20mT logistics module add on.

Total mass: 500mT
40MWe available to propulsion, 10MWe left in reserve/used/rest lost to heat
Assuming 70% propulsion system efficiency
28MW RF available for drive
Brady c TE mode @21.31 milliNewtons/kW performance propulsion system
Thrust at 28MW RF @0.02131N/kw=596N
Acceleration=0.00119200m/s^2   
Velocity after 1 year=37.59km/s, 135327km/h, 84088.5mph
Displacement 3.96AU
« Last Edit: 01/11/2015 03:27 AM by Mulletron »
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Offline aero

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Since my some months ago post interchange with Mullerton in which we more or less agreed that I should pursue the possibility of evanescent waves being the source of the EM Drive effect, I have been doing that with some results.

Using FDTD software I found the following salient points. First though, my computer is not powerful enough to perform FDTD calculations in high resolution, so I'm stuck with moderate resolution at best. That rules out resolving the thin copper sheets on the circuit board ends of the cavity. Second, there isn't any data that I can discover describing copper at this frequency and the power level experienced by the cavity ends. Sure, lots of data on copper for shielding, but ...

Consider that operating at Q = 22,000 and drive power of 2.6 watts with the cavity end diameter giving an area of 0.058 m^2 the radiation intensity approaches a kW/cm^2, or almost a MW/m^2. That is a lot of power and it seems no one has researched the behavior of copper under those intense conditions.

With those two points understood, I did calibrate the FDTD model to a photon rocket, giving thrust of very nearly 1/c as it should. This is with the detector plane about two cavity lengths behind the source antenna.

For the reasons given above, I used a perfect metal or ideal conductor as the material for the cavity model. Not surprisingly, when I ran the model totally enclosing the source with perfect metal, there was zero force detected. That result has been calculated analytically and discussed here on NSF.

I went further, considering that the end is bolted onto the cavity, what if it leaks RF? I modelled a narrow slice around the circumference of the cavity cone in the end plate, a variable sized opening but at the smallest resolution my computer will allow, 0.2% of the cavity large end radius.

The simulation detected Force/Power ranging from 2/c to 3/c.

That is two to three times the thrust of an ideal photon rocket. I think the cause of the force is evanescent waves escaping through the very narrow gap in the cavity base.

My data does not answer the question, "What causes the thrust of the EM drive?" It does point in a direction.

I can run more cases with low to moderate resolution and perfect metal, but as I wrote at the top, I need a bigger computer and better knowledge of copper behavior under intense radiation in order to calculate definitive results.

I'm sure someone will ask, so, Yes, I did look at forces generated by similar gaps in the small end of the cavity. Forces exist but only about one forth as great as at the large end. That may be directly due to the gap area, the small end circumference being about half that of the large end, and the dielectric does interfere. I should probably remove the dielectric and run some small end test cases.
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Offline Mulletron

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Welcome back!
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Offline aero

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Offline ThinkerX

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Quote
Total mass: 500mT
40MWe available to propulsion, 10MWe left in reserve/used/rest lost to heat
Assuming 70% propulsion system efficiency
28MW RF available for drive
Brady c TE mode @21.31 milliNewtons/kW performance propulsion system
Thrust at 28MW RF @0.02131N/kw=596N
Acceleration=0.00119200m/s^2   
Velocity after 1 year=37.59km/s, 135327km/h, 84088.5mph
Displacement 3.96AU

So...if I am following this correctly, allowing for deceleration, a 3 year trip to Saturn, give or take a month?  Versus a bit over 9 months for the Eagleworks proposal.

Offline ThinkerX

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Welcome back Aero!

Quote
I went further, considering that the end is bolted onto the cavity, what if it leaks RF? I modelled a narrow slice around the circumference of the cavity cone in the end plate, a variable sized opening but at the smallest resolution my computer will allow, 0.2% of the cavity large end radius.

The simulation detected Force/Power ranging from 2/c to 3/c.

That is two to three times the thrust of an ideal photon rocket. I think the cause of the force is evanescent waves escaping through the very narrow gap in the cavity base

Isn't that about on a par with Woodward's device?  The worst performer of the bunch? 

Offline RotoSequence

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Welcome back Aero!

Quote
I went further, considering that the end is bolted onto the cavity, what if it leaks RF? I modelled a narrow slice around the circumference of the cavity cone in the end plate, a variable sized opening but at the smallest resolution my computer will allow, 0.2% of the cavity large end radius.

The simulation detected Force/Power ranging from 2/c to 3/c.

That is two to three times the thrust of an ideal photon rocket. I think the cause of the force is evanescent waves escaping through the very narrow gap in the cavity base

Isn't that about on a par with Woodward's device?  The worst performer of the bunch?

I think 2x to 3x photon thrust is pretty much exactly the same number as the Woodward device, actually.

Offline MP99



... the radiation intensity approaches a kW/cm^2, or almost a MW/m^2.

10,000 sq cm in one sq metre, not 1,000.

Cheers, Martin

Offline Mulletron

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Quote
Total mass: 500mT
40MWe available to propulsion, 10MWe left in reserve/used/rest lost to heat
Assuming 70% propulsion system efficiency
28MW RF available for drive
Brady c TE mode @21.31 milliNewtons/kW performance propulsion system
Thrust at 28MW RF @0.02131N/kw=596N
Acceleration=0.00119200m/s^2   
Velocity after 1 year=37.59km/s, 135327km/h, 84088.5mph
Displacement 3.96AU

So...if I am following this correctly, allowing for deceleration, a 3 year trip to Saturn, give or take a month?  Versus a bit over 9 months for the Eagleworks proposal.

Not sure because I didn't factor in any orbital mechanics. That was just straight line constant acceleration. I'm surprised it could even move at all within a reasonable amount of time. I'm downloading something called Orbiter right now, slowly to see if I can simulate this kind of stuff. http://orbit.medphys.ucl.ac.uk/zipinstall.html Found a CPA for Saturn/Earth of 8.052au. This was in the past. Next one I don't know. Plugged that into Celestia. See screenshot.
« Last Edit: 01/11/2015 04:41 PM by Mulletron »
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Offline aero

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... the radiation intensity approaches a kW/cm^2, or almost a MW/m^2.

10,000 sq cm in one sq metre, not 1,000.

Cheers, Martin

Yes I know. That's why I weasel worded it. If we don't look at the higher power devices from Shawyer or China, just the three Brady devices, the stored power comes out as: 2.12E+006, 9.81E+005, and 5.18E+006 Watts/m^2. All shy of 1 kW/cm^2. On the other hand, other devices operate an 100 times the power level of the Brady device, even 1000 times in one particular case. ( 2.6 watts .cf. 2.5 kW)

My point is that the characteristic behavior of copper in this regime is not easy to find. (Make that impossible to find) It seems that high power radar wave guides should operate in this regime. Does anyone have a Drude  model or test data with which to create one? Or even a known material that in thick sheets, behaves like copper in thin sheets under high power radiation?


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Offline aero

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Welcome back Aero!

Quote
I went further, considering that the end is bolted onto the cavity, what if it leaks RF? I modelled a narrow slice around the circumference of the cavity cone in the end plate, a variable sized opening but at the smallest resolution my computer will allow, 0.2% of the cavity large end radius.

The simulation detected Force/Power ranging from 2/c to 3/c.

That is two to three times the thrust of an ideal photon rocket. I think the cause of the force is evanescent waves escaping through the very narrow gap in the cavity base

Isn't that about on a par with Woodward's device?  The worst performer of the bunch?

I think 2x to 3x photon thrust is pretty much exactly the same number as the Woodward device, actually.
And I think that producing thrust by making a resonant cavity and putting the end on losely is a lot easier than making a Woodward device. But that is not my point.

My point is that EM drive thrust may be produced by evanescent waves. If only I knew the behavior of copper and had a more powerful computer to run the calculations over thin sheets I could find out for sure. (I think)
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Offline Rodal

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.....
Total mass: 500mT
40MWe available to propulsion, 10MWe left in reserve/used/rest lost to heat
Assuming 70% propulsion system efficiency
28MW RF available for drive
Brady c TE mode @21.31 milliNewtons/kW performance propulsion system
Thrust at 28MW RF @0.02131N/kw=596N
Acceleration=0.00119200m/s^2   
Velocity after 1 year=37.59km/s, 135327km/h, 84088.5mph
Displacement 3.96AU

Using the following parameters from @Mulletron:

TotalMass                    500000 kgm
Power Input:                 28000000 Watts
ThrustForce/power:      0.00002131 Newton/Watt

we indeed immediately obtain:
ThrustForce:      596.7 Newtons
Acceleration:      0.001193 m/s^2

From, "Human Outer Solar System Exploration via Q-Thruster Technology" by B. Kent Joosten and Harold G. “Sonny” White, http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20140013174.pdf, their equation (4):

minimum flight time = 2 * Sqrt[(radiusTarget-radiusEarth)/Acceleration]

and the following heliocentric radii:

radiusEarth   1.496E+11 m
radiusMats   2.2794E+11 m
radiusJupiter    7.7833E+11 m
radiusSaturn    1.4246E+12 m

The following flight times for @Mulletron parameters vs the flight times (for the different parameters considered by)  "Human Outer Solar System Exploration via Q-Thruster Technology" by B. Kent Joosten and Harold G. “Sonny” White, http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20140013174.pdf follow:

From Earth to:        time @Mulletron (days/months)           time Joosten/White (days/months)

Mars                       188/6.3                                                 76/2.5                               
Jupiter                    531/17.7                                             194/6.5
Saturn                    757/25.2                                              277/9.2


The main reason for the ~3x longer flight times for Mulletron is because of the lower thrust/PowerInput considered (Mulletron=0.02131 N/kW vs. White=0.4 N/kW, hence Sqrt[0.4/0.02131]=4 times)

NOTE: The parameters considered by @Mulletron, under all cases considered (including Earth to Saturn in 757 days or 25.2 months) are safely under the "paradox condition" of Joosten/White.  There is no paradox for these Mulletron Missions: the change in kinetic energy is less than the energy consumed

The "paradox condition" of Joosten/White for the parameters considered by @Mulletron occurs at 910 days (30.3 months of continuous acceleration).


The "paradox condition" is defined as the condition for which the change in kinetic energy of the spacecraft exceeds the input energy.

Change of KineticEnergy of Spacecraft >= EnergyInput

Assuming constant thrust force (and hence constant acceleration for a constant spacecraft mass) under constant input power, the energy consumed is simply:

EnergyConsumed=Power*time

And the change in kinetic energy of the spacecraft can be expressed as:

Change of KineticEnergy of Spacecraft = mass*((change in velocity)^2)/2
                                                             = (mass/2)*((ThrustForce/mass)*time)^2)
                                                             = (mass/2)*(((ThrustForce/Power)*Power/mass)*time)^2)
Therefore

ParadoxTime = 2 * mass / (power*((thrustForce/power)^2))

see Appendix A of  "Human Outer Solar System Exploration via Q-Thruster Technology" by B. Kent Joosten and Harold G. “Sonny” White, http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20140013174.pdf and the post by Frobnicat  http://forum.nasaspaceflight.com/index.php?topic=29276.msg1281724#msg1281724 and by Mulletron http://forum.nasaspaceflight.com/index.php?topic=29276.msg1281736#msg1281736

Also, of course

Quote from: B. Kent Joosten and Harold G. “Sonny” White
should examine specific earth departure and return techniques. Unconstrained Q-Ship spiral trajectories
could expose crewmembers to undesirable levels of radiation exposure due to the Van Allen radiation belts.

« Last Edit: 01/12/2015 11:53 AM by Rodal »

Offline Vultur

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What is the evanescent wave effect? Is this a false positive (IE wouldn't work in space)?

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