Author Topic: EM Drive Developments - related to space flight applications - Thread 2  (Read 2132743 times)

Offline Notsosureofit

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Can you use your analyser in a reflectometer configuration ?

Um, no I don't think it can do that. I have an Agilent E4443A, and also an 8562A and 8562EC to use. I can't take test equipment home from work anyway. So all I can do is test at work to get data, then use the data at home.
I've had to work all weekend, so that's why I'm in test mode instead of building things and trying to find a lathe to use..... ;)

Hmmm, if you have to use a 50ohm load on the port then I think the cavity will just be acting as a matching network for the load.  Can you sketch up a layout of your connections.  (I had to go reflectometer for a customer a while back and just made up a rig to adapt my analyser...  so maybe ?)

Added:  Just thinking, I may still have it lying around, I'll look tomorrow !  (50ohm if I remember !)

It's just a 3-port bridge using Mini-Circuits  (have to check the freq range)

 
« Last Edit: 03/22/2015 02:46 PM by Notsosureofit »

Offline Star-Drive

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Mulletron:

In regards to your sense antenna port on the copper frustum, when not being used for taking VNA S21 frequency sweep plots I either leave our sense antenna as an open circuit, AKA in a high-Z state, or use it as a feedback control signal for our phase locked loop (PLL) circuit.  If the latter, I still have to make the E-field sense antenna in the frustum very small, (like just the solder cup on an SMA bulkhead connector), so as to not overload the PLL's mixer input.   Even with this small of an antenna, I still have to add at least 40 dB of 2W each 5-to-10 dB attenuator pads to the sense antenna's output to keep the PLL's mixer circuit from overloading.  And the higher the Q-factor of the mode under study, the more sense antenna padding isolation that is required.

Best,  Paul M.
Star-Drive

Offline Star-Drive

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@ Star-Drive

"EDIT 4:  @Star-Drive: up-thread the participants were trying to get your attention on the reverse thrust condition."

-from Stormbringer

Thanks


Notsosureofit:

The reverse thrust signals for the 1937.15MHz thrust signals are not the negative going mirror images of the forward or positive going thrust signatures as one would have liked.  I'm still trying to understand why this is so, but I think it means that the force measurement system is not symmetric in its response to left and right going force inputs at the low thrust magnitudes we are currently having to put up with, since I've already shown that the frustum produces similar thrust values both inside and outside the stainless steel vacuum chamber.  I've appended two slides to this post that show the forward and reverse signals in-air on one slide at 50W and then just the reverse thrust signal in-vacuum at 35W.  I've also appended the frustum out of the vacuum chamber thrust run, noisy as it is for your inspection. 

Bottom line to all this is we need more thrust to work with and from our current COMSOL/QV-Plasma Code runs now for the TM010 mode at 942 MHz, its becomes very apparent we really need to increase our power levels into the 1.0-to-10kW-rf range or even higher.  And yes they may validate the magnitude of thrust data that Shawyer's and Chinese's reported even without dielectrics in the cavity.  Of course one data point is only suggestive, but it sure points us to where we have to go to truly validate these conjectures.  However that course of action requires resources that are at present not available to the Eagleworks lab... 

BTW, these COMSOL/QV-Plasma Code thrust predictions may be reporting up to an order of magnitude low from what the real test article will generate at the noted power levels as shown in the last appended slide.

Best, Paul M.
Star-Drive

Offline Rodal

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@ Star-Drive

"EDIT 4:  @Star-Drive: up-thread the participants were trying to get your attention on the reverse thrust condition."

-from Stormbringer

Thanks


Notsosureofit:

The reverse thrust signals for the 1937.15MHz thrust signals are not the negative going mirror images of the forward or positive going thrust signatures as one would have liked.  I'm still trying to understand why this is so, but I think it means that the force measurement system is not symmetric in its response to left and right going force inputs at the low thrust magnitudes we are currently having to put up with, since I've already shown that the frustum produces similar thrust values both inside and outside the stainless steel vacuum chamber.  I've appended two slides to this post that show the forward and reverse signals in-air on one slide at 50W and then just the reverse thrust signal in-vacuum at 35W.  I've also appended the frustum out of the vacuum chamber thrust run, noisy as it is for your inspection. 

Bottom line to all this is we need more thrust to work with and from our current COMSOL/QV-Plasma Code runs now for the TM010 mode at 942 MHz, its becomes very apparent we really need to increase our power levels into the 1.0-to-10kW-rf range or even higher.  And yes they may validate the magnitude of thrust data that Shawyer's and Chinese's reported even without dielectrics in the cavity.  Of course one data point is only suggestive, but it sure points us to where we have to go to truly validate these conjectures.  However that course of action requires resources that are at present not available to the Eagleworks lab... 

BTW, these COMSOL/QV-Plasma Code thrust predictions may be reporting up to an order of magnitude low from what the real test article will generate at the noted power levels as shown in the last appended slide.

Best, Paul M.

What does "reversed" mean in the above discussion and plots?  does it mean:

1) Turning around by 180 degrees the EM Drive, such that the thrust force and thrust motion still points towards the small base of the truncated cone?

(just like turning around by 180 degrees a car driving in "D" will result in it moving forward in the opposite direction)



or

2) The "reversed" thrust force and thrust motion points towards the big base of the truncated cone. 

(just like putting a car in reverse "R" will make the car move backward instead of forward)

Where one defines 

forward thrust = thrust force and thrust motion pointing towards the small base of the truncated cone

reverse thrust = thrust force and thrust motion pointing towards the big base of the truncated cone

« Last Edit: 03/22/2015 04:09 PM by Rodal »

Offline Star One

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If I'm understanding this right is there a kind of catch 22 at work here. To validate if this drive works or not you need a greater power input, but to obtain access to a greater power input it has to be proved that it works first?

Offline Notsosureofit

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@ Star-Drive

Have there been any experimental runs that show force towards the big end ??

Offline Star-Drive

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@ Star-Drive

Have there been any experimental runs that show force towards the big end ??


All:

1. For my post of earlier today reversed thrust means physically reversing the frustum test article 180 degrees from its previous "forward" position.

2.  I've also observed several test setups that generated reversed thrust signatures without physically turning the thruster around 180 degrees in its mount.  One of these instances was with the current copper frustum and the others were with my two Mach Lorentz Thrusters (MLT) as reported in my STAIF-2006 paper.  Thrust reversal was obtained in those test setups by reversing the E-field & B-field drive polarities via relay control.

Best, Paul M.
Star-Drive

Offline Rodal

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@ Star-Drive

Have there been any experimental runs that show force towards the big end ??


All:

1. For my post of earlier today reversed thrust means physically reversing the frustum test article 180 degrees from its previous "forward" position.

2.  I've also observed several test setups that generated reversed thrust signatures without physically turning the thruster around 180 degrees in its mount.  One of these instances was with the current copper frustum and the others were with my two Mach Lorentz Thrusters (MLT) as reported in my STAIF-2006 paper.  Thrust reversal was obtained in those test setups by reversing the E-field & B-field drive polarities via relay control.

Best, Paul M.

The bell just tolled: my understanding of what "reverse" meant in your plots was thereby defenestrated corrected  :)

Is there a position vs. time plot of the "One of these instances ... with the current copper frustum" with the force  directed towards the big end?  If so, can you make that plot available?

What was the frequency, mode shape, thrust force, Q, input power and testing environment corresponding to the case exhibiting a thrust force pointed towards the big base?

It is very important to report this case because it defenestrates nullifies mechanistic theories proposed to explain the NASA Eagleworks measurements as an experimental mechanical artifact having no application whatsoever for spaceflight applications.
« Last Edit: 03/22/2015 05:54 PM by Rodal »

Offline Mulletron

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Mulletron:

In regards to your sense antenna port on the copper frustum, when not being used for taking VNA S21 frequency sweep plots I either leave our sense antenna as an open circuit, AKA in a high-Z state, or use it as a feedback control signal for our phase locked loop (PLL) circuit.  If the latter, I still have to make the E-field sense antenna in the frustum very small, (like just the solder cup on an SMA bulkhead connector), so as to not overload the PLL's mixer input.   Even with this small of an antenna, I still have to add at least 40 dB of 2W each 5-to-10 dB attenuator pads to the sense antenna's output to keep the PLL's mixer circuit from overloading.  And the higher the Q-factor of the mode under study, the more sense antenna padding isolation that is required.

Best,  Paul M.

That's good advice about making the sense antenna small. What I have right now, the sense antenna is as good at coupling energy out of the cavity as the feed antenna is at getting energy into the cavity. They are both the same and interchangeable.

During my testing I noted that the terminated sense antenna port played a huge role on how much power was reflected back into the directional bridge connected to the frustum input port.

Based on what I learned today from testing and from you, the sense antenna port should be impedance matched to whatever is driving the frustum and what is attached to the sense port, but it need not be (and shouldn't be) an efficient coupler of energy out of the cavity for the sake of the cavity storing as much energy as possible and for the sake of the test equipment attached. This lesson learned applies to during force testing with higher power levels.

During low power VSWR testing and other tests, a matched input/sense port is ideal for an accurate test. In the next post, I'll show how I can efficiently couple energy into and out of the cavity (from sweep gen to power meter/spectrum analyzer) at certain frequencies and only lose a couple db of power in the round trip. Exact figures will be in that post.

Based on what you're saying, I'm going to make another (hobbled) sense antenna, for now it will be just a solder cup. Then I will repeat the same VSWR test to see how things change.

I will also do a VSWR test with NO sense antenna, the hole will be covered in conductive copper tape on both sides similar to what's in this shot here:
http://forum.nasaspaceflight.com/index.php?action=dlattach;topic=36313.0;attach=785112;image
http://forum.nasaspaceflight.com/index.php?topic=36313.msg1331854#msg1331854

I won't be working with much power so I have to be certain I don't waste even a milliwatt of power, so that's why I'm digging into the sense antenna and also making sure that I get the very lowest VSWR as possible on the input.



« Last Edit: 03/22/2015 06:22 PM by Mulletron »
Challenge your preconceptions, or they will challenge you. - Velik

Offline Chrochne

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Quoted:
Bottom line to all this is we need more thrust to work with and from our current COMSOL/QV-Plasma Code runs now for the TM010 mode at 942 MHz, its becomes very apparent we really need to increase our power levels into the 1.0-to-10kW-rf range or even higher.  And yes they may validate the magnitude of thrust data that Shawyer's and Chinese's reported even without dielectrics in the cavity.  Of course one data point is only suggestive, but it sure points us to where we have to go to truly validate these conjectures.  However that course of action requires resources that are at present not available to the Eagleworks lab... 
(By Star-Drive)

I noticed that Mr. Roger Shawyer suggested something similar, when it comes to high power tests of his second generation engine.
http://emdrive.com/secondgenengines.html . Is there something similar in the USA as European Tesla accelerator? Just a thought.

Additionaly, I am starting to see some similarities between the NASA, Chinese and Mr. Shawyer. All are suggesting a high power tests might really be needed. Question now is how to do that. I pressume it can be really expensive. But NASA might have better chance to reach European Tesla accelerator than Mr. Shawyer do. It would be nice to see some sort of cooperation between above suggested parties on this.

Anyway, thank you all for continuing dabate. For me personaly it gives hope and great insight into the keen minds of the people. Thank you.
 


Offline Mulletron

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So here is the amplitude response test which measures gain/loss over a frequency range. This test is centered on 2450mhz with a span of 125mhz. This is an automated test and uses the following:

*HP Agilent 8757E SNA with (1) *11664A detector and (1) *85025A detector.
*HP 11667A power divider
*HP 83752B Sweep generator @0dbm
*Gigatronics 8542C power meter w/*80301A sensor
Laptop running test software controlling sweep generator and SNA
*6db and *3db attenuators to protect gear, 6db on input cable, 3db on detector (accounted for in cal loop)
(1) 6' high quality test cable
*=Calibrated by a lab

All gains and losses not from the DUT are accounted for in the cal loop.

There was a calibrated 0dbm of power input to the frustum as measured by a power meter. The output of the frustum is measured by a detector on the sample port of the frustum. The sweep is obtained by comparing a reference detector attached to the signal generator output at power divider port, with the detector attached to the frustum output.

Before the test is run, a cal loop is run, where the DUT is replaced by a N-type female bullet adaptor. So the input cable is directly connected to the output detector by an rf bullet adaptor.

After the cal run, the bullet is replaced by the DUT.

This gives a nice overview of what is happening in the frustum, but doesn't give much detail.

A post will follow with data from a spectrum analyzer showing the same amplitude response with more detail. This is essentially the same test but done manually without an SNA.
« Last Edit: 03/22/2015 07:12 PM by Mulletron »
Challenge your preconceptions, or they will challenge you. - Velik

Offline Star-Drive

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@ Star-Drive

Have there been any experimental runs that show force towards the big end ??


All:

1. For my post of earlier today reversed thrust means physically reversing the frustum test article 180 degrees from its previous "forward" position.

2.  I've also observed several test setups that generated reversed thrust signatures without physically turning the thruster around 180 degrees in its mount.  One of these instances was with the current copper frustum and the others were with my two Mach Lorentz Thrusters (MLT) as reported in my STAIF-2006 paper.  Thrust reversal was obtained in those test setups by reversing the E-field & B-field drive polarities via relay control.

Best, Paul M.

The bell just tolled: my understanding of what "reverse" meant in your plots was thereby defenestrated corrected  :)

Is there a position vs. time plot of the "One of these instances ... with the current copper frustum" with the force  directed towards the big end?  If so, can you make that plot available?

What was the frequency, mode shape, thrust force, Q, input power and testing environment corresponding to the case exhibiting a thrust force pointed towards the big base?

It is very important to report this case because it defenestrates nullifies mechanistic theories proposed to explain the NASA Eagleworks measurements as an experimental mechanical artifact having no application whatsoever for spaceflight applications.

Dr. Rodal:

The copper frustum thrust reversal due to only its dielectric placement came when I was experimenting with the TM010 mode, when I cut back the HDPE disc count to one, while the copper frustum was mounted in its little OD pointed to the right or forward position.  I then removed the HDPE disc and replaced it with one 5.13" OD by 1.06" thick PTFE discs that was mounted at the large OD end of the copper frustum with the frustum still mounted in the same direction as the first TM010 test, i.e., with its small OD end pointed toward the right in the vacuum chamber.  The attached slides summarizes these two test series at 954MHz (1 HDPE Disc) and 901 MHz (1 Teflon Discs at Large OD end).

Best,

Offline Mulletron

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And here's a sample of the spectrum analyzer test. All this test involves is injecting a calibrated 0dbm input signal to the frustum, then seeing what comes out the other side on the spectrum analyzer.

*HP 83752B Sweep generator @0dbm
*Agilent E4443A spectrum analyzer
*Gigatronics 8542C power meter w/*80301A sensor
(2) 6' high quality test cables
*=Calibrated by a lab

Combine this with the VSWR data and the behavior of the unloaded frustum between 2400-2500mhz becomes apparent. The points where the VWSR is really poor is evident in the amplitude response, seen in the spectrum analyzer shots, so these two tests validate each other.

Rest is here:
https://drive.google.com/folderview?id=0B4PCfHCM1KYoUEx5dzlVTG81a2c&usp=sharing&tid=0B4PCfHCM1KYoTXhSUTd5ZDN2WnM

Other frequencies here:
(disclaimer, my E field probe is not optimized for all these frequencies, still useful to see what other frequencies couple to the cavity with low VSWR using my 31mm probe/cavity combination)
The best peaks of other frequencies are labeled similar to the bottom screen shot.
https://drive.google.com/folderview?id=0B4PCfHCM1KYoVkRzUGNuMVBLbVk&usp=sharing&tid=0B4PCfHCM1KYoTXhSUTd5ZDN2WnM

« Last Edit: 03/22/2015 08:33 PM by Mulletron »
Challenge your preconceptions, or they will challenge you. - Velik

Offline frobnicat

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Thank you Paul March for clarifying the situation concerning "true" reversal and sharing precious experimental data points.

Before everyone agrees about what is to be explained in those results, maybe you could further confirm the proper interpretation of orientations (for which clear communication and universal reading is surprisingly difficult) :

Dr. Rodal:

The copper frustum thrust reversal due to only its dielectric placement came when I was experimenting with the TM010 mode, when I cut back the HDPE disc count to one, while the copper frustum was mounted in its little OD pointed to the right or forward position. 

Usually in your reports the "forward" direction implies the small OD toward the left, (as seen when standing in front of vacuum chamber). The 2 frustum setup attached pictures show the small OD toward the left. Should we understand here that the small OD end is actually to the left ? Pictures are self consistent and consistent with the usual use of forward in previous reports. Saying "little OD pointed to the right" seems contradicting. Is it correct to understand that the small OD end is on the left (as seen on pictures), and that the first frustum thrust picture shows a thrust toward the big OD end (red arrow) ? There is in this experiment 1 PE disc, is it at the small OD end or at the big OD end ?
bigger


Quote
I then removed the HDPE disc ...

That was at small OD end ? Big OD end ?

Quote
... and replaced it with one 5.13" OD by 1.06" thick PTFE discs that was mounted at the large OD end of the copper frustum with the frustum still mounted in the same direction as the first TM010 test, i.e., with its small OD end pointed toward the right in the vacuum chamber.
 

Again saying "small OD end pointed toward the right" seems to contradict the picture (while all the rest is consistent).
bigger


Quote
The attached slides summarizes these two test series at 954MHz (1 HDPE Disc at which OD end ?) and 901 MHz (1 Teflon Discs at Large OD end).

Sorry for this "nitpicking", this is to avoid long arguments on interpretation, and discuss conjectures on common ground.

Best

Offline Star-Drive

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My bad, I meant to the left....

(That's what I get when I'm in a hurry and let my dyslexia get out.)

Best, Paul M
Star-Drive

Online Stormbringer

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Someone else is making an EM drive:  http://www.scientificamerican.com/article/worlds-first-flying-saucer/

  It's probably the april first addition.  ;) and it works like one of those 400 dollar ionic wind Dyson fans.

It's not the april first addition but its from july 2008.
« Last Edit: 03/23/2015 05:18 AM by Stormbringer »
When antigravity is outlawed only outlaws will have antigravity.

Online Damon Hill

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http://www.dtic.mil/dtic/tr/fulltext/u2/a564120.pdf?

"Demonstration of a wingless electromagnetic air vehicle"

Pretty much proof-of-concept, goes into lots more detail than I have endurance to read.

Offline Star-Drive

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http://www.dtic.mil/dtic/tr/fulltext/u2/a564120.pdf?

"Demonstration of a wingless electromagnetic air vehicle"

Pretty much proof-of-concept, goes into lots more detail than I have endurance to read.

Damon:

Good grief man, this is a great find!!  And an R&D activity I didn't even know was going on.  Now to figure out what is conventional plasma physics and what might be extended EM-Drive physics hiding in this University of Florida paper.

Thanks again,

Best, Paul M.   
Star-Drive

Offline Rodal

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This technology (http://www.dtic.mil/dtic/tr/fulltext/u2/a564120.pdf ) uses classical physics for propulsion: electrodes that cover its surface to ionize the surrounding air into plasma.   

It cannot work in outer space because there is no surrounding air to ionize and use for lifting purposes.

There is no connection to the profound issues (conservation of momentum) and the proposed esoteric explanations (Quantum Vacuum, Mach Effect, coupling of electromagnetics with gravity, Unruh radiation, etc.) of the EM Drive,
because the EM Drive does not carry on-board any propellant and it is supposed to not rely on surrounding air for propulsion.

MIT's Aero & Astro Department has micro thrusters  (made of tiny chips) technology using electrospray propulsion to use in outer space, but it is also based on classical physics:

http://newsoffice.mit.edu/2015/accion-systems-thruster-for-small-satellites-0311#.VQGgo9sCC8A.linkedin

http://www.leonarddavid.com/tiny-thruster-offers-big-promise/

http://newsoffice.mit.edu/2012/microthrusters-could-propel-small-satellites-0817












« Last Edit: 03/23/2015 12:05 PM by Rodal »

Offline flux_capacitor

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The Wingless Electromagnetic Air Vehicles (WEAV) is a recent concept of electrohydrodynamic (EHD) flying disc, derived from plasma actuators. It uses the electrophoretic coulomb and polarization forces to ionize air and accelerate the resulting plasma, literally sucking it radially from top of the device, where it creates a lower pressure area, hence a lift.

You can also produce similar bur greater suction using magnetohydrodynamics (MHD) with Lorentz forces F = q (E + v × B). Well, it would cost more than EHD because you need to create a strong magnetic field in the multi-tesla range; and the electrothermal instability becomes really tricky in magnetized non-thermal plasmas. But such MHD forces can accelerate a plasma to hypersonic speeds. I know that quite well because I used to work with a plasma physicist, expert in this field since 1975. Attached, a paper summarizing that research (scroll to section VII. Induction MHD aerodynes, pp. 12-15):

J.P. Petit; J. Geffray, F. David (19-22 October 2009). "MHD Hypersonic Flow Control for Aerospace Applications", AIAA-2009-7348, in 16th AIAA/DLR/DGLR International Space Planes and Hypersonic Systems and Technologies Conference (HyTASP), Bremen, Germany.

Whatever, I second Dr Rodal: despite using advanced concepts, with only electricity and no fuel on board, and having an unusual odd shape, those conceptual flying saucers are not propellantless thrusters, since they have to accelerate ambient air for propulsion. This is leading-edge, but still classical physics.

[EDIT]: A 20ft diameter MHD disc would be quite heavy, requiring about 100 MWe of (preferably fusion) electric power on board in order to overcome its weight. May I suggest to add one… hum no, three EmDrives below the hull (at 120° from each other) in order to lighten a bit that flying mammoth? ;)
« Last Edit: 03/23/2015 12:32 PM by flux_capacitor »

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