Author Topic: EM Drive Developments - related to space flight applications - Thread 2  (Read 2097877 times)

Online Flyby

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Apologies to all. I thought I had read all the older forum pages. Seems I missed quite a few. Just about finished.

What I did find and confirmed via a search is that Shawyer's latest revelation, in an email to Mullerton, was that the Flight Thruster end plates WERE SHAPED seems to have missed making the headlines.

I did read there was quite a bit of speculation during the time the Flight Thruster dimensions were being worked out as to whether the end plates were flat or shaped.

So how we have it from Shawyer himself, the Flight Thruster was designed to have a high Q (narrow bandwidth), use a narrow band RF generator and have shaped end plates. Seems we finally know for sure why the end plates were so thick.

euhmm... came to the same conclusion...just didn't add the pretty pictures... ;D
http://forum.nasaspaceflight.com/index.php?topic=36313.msg1369324#msg1369324

Offline RotoSequence

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Apologies to all. I thought I had read all the older forum pages. Seems I missed quite a few. Just about finished.

What I did find and confirmed via a search is that Shawyer's latest revelation, in an email to Mullerton, was that the Flight Thruster end plates WERE SHAPED seems to have missed making the headlines.

I did read there was quite a bit of speculation during the time the Flight Thruster dimensions were being worked out as to whether the end plates were flat or shaped.

So how we have it from Shawyer himself, the Flight Thruster was designed to have a high Q (narrow bandwidth), use a narrow band RF generator and have shaped end plates. Seems we finally know for sure why the end plates were so thick.

euhmm... came to the same conclusion...just didn't add the pretty pictures... ;D
http://forum.nasaspaceflight.com/index.php?topic=36313.msg1369324#msg1369324

You certainly did! You also ended up with a bottom-of-the-page post, which are fairly easy to miss; that never helps.  :)

Offline TheTraveller

Here is my KISS EMDrive test system rough draught.

The EM Drive will sit on top of but not connected to one end of a balance beam. On the other will be an adjustable counter balance mass. Very low stiction bearings will be used.

The EM Drive end of the balance beam will sit on top of but not connected to a digital load cell with a 0.01g resolution / 0.5kg max and be connected via USB to a laptop running data logger software. Would like more resolution, will see how the budget goes.

The counter balance will be adjusted to produce a down force on the load cell of 0.25kg when the EM Drive is unpowered so to bias the load cell into the middle of it's range.

The frequency and power adjustable RF source will be connected to the EM Drive by a free floating length of coax with SWR matching capability and to the laptop via USB connector. Control of frequency and power will be via software on the laptop.

Fairly long power pulses of of upto 2 minutes will be applied to the EM Drive as per Shawyer's 1st test protocol. http://emdrive.com/feasibilitystudy.html

The idea is to keep this KISS and stay as close to the 1st Shawyer test setup that also used vertical orientation of the EM Drive.

Based on achieving 10mN/kW (~1gf/kW) performance, the desired 0.1gf (10x load cell resolution) will need the application of 100W of RF power.

Desire is to use common 2.4GHz narrow band WiFi based signal generators which can be smoothly varied in frequency and power output to find optimal cavity frequency and energy loading.

As this is a narrow band RF signal, ideally the end caps should be spherical to eliminate end plate variable phase change and to get a much better cavity Q. But being a realist and KISS engineer, who hates to reinvent the wheel, will start with simpler flat plates and will follow the excellent work of Mullerton.

Comments most welcome

One possible problem I see with your proposed experiment is the coiled coax.   There will always be a significant error force from that and there is no simple way of cancelling it out.    Maybe a telescoping waveguide feed would solve that problem.   The load cell will also be in jeopordy.  Too much imbalance will crush it.
Thanks for the feedback.
Most appreciated.

RF coax layout has been modified. Feed will come up through a small hole at the balance point of the Teeter Totter like balance beam system.

Load cell concerns are valid. Plan to use a block under the EM Drive side of the balance system until it is closely balanced, then remove the block, allowing the EM Drive side of the system to contact the load cell and then adjust the balance weight to get a 0.25kg reading on the load cell or it is operating in the centre of it's range and the data logger can record any resultant increase or decrease in EM Drive weight.

RF frequency, power usage of the RF amplified, internal spectral scan from an internal sense antenna, RF power output, cavity top, middle and bottom temperature and load cell deviation += 0.25kg will be recorded with a data logger.

Will also be movement limits on the balance beam teeter totter.
"As for me, I am tormented with an everlasting itch for things remote. I love to sail forbidden seas.”
Herman Melville, Moby Dick

Offline TheTraveller

Apologies to all. I thought I had read all the older forum pages. Seems I missed quite a few. Just about finished.

What I did find and confirmed via a search is that Shawyer's latest revelation, in an email to Mullerton, was that the Flight Thruster end plates WERE SHAPED seems to have missed making the headlines.

I did read there was quite a bit of speculation during the time the Flight Thruster dimensions were being worked out as to whether the end plates were flat or shaped.

So how we have it from Shawyer himself, the Flight Thruster was designed to have a high Q (narrow bandwidth), use a narrow band RF generator and have shaped end plates. Seems we finally know for sure why the end plates were so thick.

euhmm... came to the same conclusion...just didn't add the pretty pictures... ;D
http://forum.nasaspaceflight.com/index.php?topic=36313.msg1369324#msg1369324

You certainly did! You also ended up with a bottom-of-the-page post, which are fairly easy to miss; that never helps.  :)
Good news is the shaped end plates are no longer speculation nor conjecture. The guy who made the Flight Thruster has told us they are shaped.

So WELL DONE. Seems the speculation / conjecture was SPOT ON.
"As for me, I am tormented with an everlasting itch for things remote. I love to sail forbidden seas.”
Herman Melville, Moby Dick

Offline ThereIWas3

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How much power are you planning on putting through that coax?  The thicker it gets, the stiffer it gets, which would mess up any delicate movements of the balance beam.  My experience is with amateur radio, and there 50 watts is the most you would try to put through something like RG-59 (looks like cable-TV cable).   RG-8, which can handle a kilowatt, is about 1 cm in diameter and not very flexible at all.

Power losses in the cable of course turn into heat...
"If you want to build a ship, don’t drum up people to collect wood and don’t assign them tasks and work, but rather teach them to long for the endless immensity of the sea" - Antoine de Saint-Exupéry

Offline Mulletron

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I am afraid that Star-Drive...aka Paul March may not come back. We had such a productive collaboration. That was open source science happening right before the World's eyes.

We'll reach the stars someday, and you're getting us there...one data point at a time.

« Last Edit: 05/05/2015 05:27 PM by Mulletron »
Challenge your preconceptions, or they will challenge you. - Velik

Online Rodal

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Chinese did report their cavity bandwidth data:
http://www.emdrive.com/yang-juan-paper-2012.pdf

Interesting.   Earlier in the first thread the discussion centered around cavity Q and the need for a high Q.   This cavity only has a Q = 1531.

The 2013 paper from NWPU: "It was found that the thruster
cavity made by copper and resonating on the equivalent TE011
mode has a quality factor 320400 and generates total net EM
thrust 411 mN for 1000 W 2.45 GHz incident microwave." 
http://iopscience.iop.org/1674-1056/22/5/050301
The Q's reported in the tables 1 and 2 of http://www.emdrive.com/NWPU2010paper.pdf  and in the above quote are much higher than the calculated Q based on the bandwidth. 

Zen-In's calculated Q from the bandwidth is correct: Q = f/bandwidthf (by definition)

Can anybody make sense of the discrepancy?

Zen-In's calculated Q from the bandwidth is correct: Q = f/bandwidthf (by definition), but the Q's reported in the tables 1 and 2 of http://www.emdrive.com/NWPU2010paper.pdf  and in the above quotes are much higher than the calculated Q based on the bandwidth.

Paul March has addressed  and explained this as follows: Chinese (Prof. Yang) calculated loaded Q factors are much higher than the Q's reported by Shawyer and by NASA' Eagleworks because of the unorthodox way that the Chinese calculate their loaded Q factors.  Instead of using the S11 zero dB reference plane to measure their -3dB down bandwidths from, as is done elsewhere, the Chinese use the most negative dB S11 value located at the resonance frequency and measure up 3dB toward the S11 zero  dB plane.  Therefore, of course, the bandwidth figures used by the Chinese in this unorthodox calculation are going to be ridiculously small which yields correspondingly artificially large values of the calculated Q-factor.  Prof. Yang's most recent paper containing the embedded thermocouple temperature measurements spell this out very clearly.


BOTTOM LINE: We have to communicate in a common language.  When discussing Q's for Prof. Yang's experiments we cannot use Prof. Yang's calculated Q's as they are artificially high due to her unorthodox calculation.  Instead, the procedure followed by Zen-In should be followed, which gives the real Q (which is actually lower than the Q's measured by NASA Eagleworks or by Shawyer).
« Last Edit: 05/05/2015 05:34 PM by Rodal »

Offline CW

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BTW, I think Mr. Shawyer claimed that there was no dielectric inserted into his cavity at all because it was not needed for its functioning. Technically though, that's not possible with materials like copper and aluminum. They instantly oxidize during manufacture of the cavity. So, the standing EM waves will encounter a dielectric on any metallic surface.
« Last Edit: 05/05/2015 05:27 PM by CW »
Reality is weirder than fiction

Online Rodal

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I am afraid that Star-Drive...aka Paul March isn't coming back. We had such a productive collaboration. That was open source science happening right before the World's eyes.

We'll reach the stars someday, and you're getting us there...one data point at a time.

Have you heard something to that effect ?  I have heard it said that NASA has asked them to not discuss NASA work in any public forum, because of what was written in the media (NASA warping space by accident, NASA working on a Star-Trek spaceship, etc.) . 
« Last Edit: 05/05/2015 05:38 PM by Rodal »

Offline Stormbringer

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I am afraid that Star-Drive...aka Paul March may not come back. We had such a productive collaboration. That was open source science happening right before the World's eyes.

We'll reach the stars someday, and you're getting us there...one data point at a time.
Maybe someone can tell him we've settled down here.  Did the tumult from a few of the new thread participants because of the new publicity discourage him?
When antigravity is outlawed only outlaws will have antigravity.

Offline Star One

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I am afraid that Star-Drive...aka Paul March may not come back. We had such a productive collaboration. That was open source science happening right before the World's eyes.

We'll reach the stars someday, and you're getting us there...one data point at a time.

I was afraid this might happen. Which is a crying shame but perhaps was inevitable once this hit big with the net & attracted the attention of certain denizens of its realm. I really do pray this doesn't fatally impede research into this subject.
« Last Edit: 05/05/2015 05:37 PM by Star One »

Online Flyby

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I am afraid that Star-Drive...aka Paul March isn't coming back. We had such a productive collaboration. That was open source science happening right before the World's eyes.

We'll reach the stars someday, and you're getting us there...one data point at a time.

Is that your personal fear or an unofficial confirmation?

From a personal point of view, that is what I feared the most when I saw how the summary article got mangled , twisted and tortured on some of the more populist science sites.

NASA has a reputation to guard (of performing reliable science and research) and the assumptions made in those other populist articles really corner NASA into a position that -I can  imagine- wouldn't be too pleasing for those at the top of the organization...
If I were in their shoes, i wouldn't be very happy either with the "NASA discovers StarTrek like warp-drive" silliness...
And that the finger waving reaches the lab staff wouldn't surprise me at all.
All these things draw an amazing amount of unwanted FLAK...

Publicity cuts both ways... always...

I really hope P.March reports back to us at certain point with an update on their high power microwave test. Cause that test is going to be soooooo important...

Offline Mulletron

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Changes are happening on http://www.emdrive.com/

Mr. Shawyer is speaking to us and we can offer him a forum here if he so desires.

This is new:
NWPU 2010 unpublished test results
http://www.emdrive.com/NWPU2010testresults.pdf
« Last Edit: 05/05/2015 05:43 PM by Mulletron »
Challenge your preconceptions, or they will challenge you. - Velik

Offline zen-in

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I am afraid that Star-Drive...aka Paul March may not come back. We had such a productive collaboration. That was open source science happening right before the World's eyes.

We'll reach the stars someday, and you're getting us there...one data point at a time.

That's to bad.  I hope it is only temporary.   Paul's honesty and commitment to answering our questions was very helpful.    It is not  an enviable task to be doing research in a high risk / high yield area and also fielding questions from the general public.   He deserves a break from all that.

Offline Mulletron

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BTW, I think Mr. Shawyer claimed that there was no dielectric inserted into his cavity at all because it was not needed for its functioning. Technically though, that's not possible with materials like copper and aluminum. They instantly oxidize during manufacture of the cavity. So, the standing EM waves will encounter a dielectric on any metallic surface.

Yes and air is also a dielectric and it has been shown experimentally that plain old air exhibits magnetoelectric non-reciprocity under similar conditions.

https://www.google.com/search?q=non+reciprocity+casimir+momentum&ie=utf-8&oe=utf-8
Challenge your preconceptions, or they will challenge you. - Velik

Offline Mulletron

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I am afraid that Star-Drive...aka Paul March isn't coming back. We had such a productive collaboration. That was open source science happening right before the World's eyes.

We'll reach the stars someday, and you're getting us there...one data point at a time.

Have you heard something to that effect ?  I have heard it said that NASA has asked them to not discuss NASA work in any public forum, because of what was written in the media (NASA warping space by accident, NASA working on a Star-Trek spaceship, etc.) .

I haven't heard anything like that but it makes perfect sense. I see where Star-Drive is logging into this site but he isn't commenting anymore.  :(
Challenge your preconceptions, or they will challenge you. - Velik

Online Flyby

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while realizing my knowledge of electromagnetism falls short compared to level that is discussed here, i do have a question about that interesting idea on momentum transfer of the waves :

-with the law on conservation of energy in the back of my head -
 
How can the momentum transfer of a wave be bigger then the energy contained in a photon, as seen in a pure photon rocket ? I believe calculations showed the forces observed in the frustum are many times (100? 1000?) greater then what a photon rocket would be able to produce...

Due to the duality of microwave being a photon particle and a wave at the same time, shouldn't the energy contained in a wave/particle be the same?

Is it because for a photon rocket only a small portion of that energy is used for kinetic motion, while in the momentum transfer a greater part of the energy is transferred? ???
Concerning Todd's formulation, I attach below his reply that was posted in another thread, that may also be of help concerning the above question:

COM=conservation of momentum
GR=General Relativity

His answer has to do with the "gravitational field" inside the cavity, which can have different levels of energy :
(in one post he suggested that the experimenters should post a label on the frustum reading "Gravitational Field Inside")
I'm trying to wrap my head around this, so let's see if i got this right...(in simple wording)

Due to the shape of the frustum, energy is gradually compressed going from the large base to the small base. (energy density differs along the longitudinal axis).
 This energy increase also causes a denser gravitational field, effectively slowing down electromagnetic waves, who transfer part of their momentum energy to the frustum...
I can more or less see how "gravitational drag" can cause a forward motion for wave moving towards the small end... but what about the returning waves?

Do they accelerate again when the gravitational field inside the frustum decreases (going from small to large base) , hence nullifying the forward momentum..

or

do they keep their lower energy state on the way back, hence slowly dying out to zero after X bounces?

or.. did i completely miss the point? :'(

Offline aceshigh

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I wonder if, while not possible to post directly here anymore, Paul March would still be allowed to indirectly communicate with this open-source science experiment, by answering questions/talking with a specific person FROM the forum (like Dr Rodal maybe).


in some way that he keeps helping us (and people from here helping him with suggestions, etc) BUT when he answers something, that cannot be directly attributed to NASA?

Offline CW

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I was wondering about the following:

The tapered frustum's sole purpose is to create a standing EM wave of specific frequency. As far as I remember, a standing wave could also be interpreted as a confined particle in quantum mechanics. Is there any possibilty that the standing waves within the cavity resemble dynamically created exotic matter that shows weird behavior when interacting with the 'normal' matter that the EM-drive is made of?

This is at least similar to some claims made by Dr white. However I am not sure I have properly understood what he meant when he said these things are doing essentially the same thing the QVPT does and (I think?) maybe he said the QVPT and the Warp Interferometry test article got it's negative energy from the vacuum. Anyhow it may be that your supposition aligns with Dr White but i am not completely sure I understand it.

Who does?
;)

Anyway.. I can't help now but picture the confined, standing EM wave as being equivalent to a giant exotic particle that is being squeezed into a metal can made of ordinary matter.

One thing about the dielectric in the cavity also strikes me as similar to what the standing wave of an electron would experience, if the atomic orbital of an electron were squeezed or compressed, so that the current wavelength of the electron does not really fit onto the orbital anymore. Question: What happens to the electron, when the orbital is compressed? Does the wavelength shorten, what would actually happen?
« Last Edit: 05/05/2015 06:28 PM by CW »
Reality is weirder than fiction

Offline sanman

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From what I remember, originally there was the Alcubierre "Warp Drive" concept proposed by Mexican physicist Miguel Alcubierre, which required a jupiter-sized mass of dark matter. Then Dr White came up with a refinement of the geometry, so that the amount of dark matter was much less (someone compared it to the mass of the Voyager space probe.) Then Dr White announced his intention to test whether a "space warp" was possible, by using a Michelson interferometer to try to detect a path-length difference when a voltage was applied to a capacitor ring.

So that stuff was all purely related to Alcubierre "Warp Drive". And of course news media were widely reporting that NASA was researching how to develop a Warp Drive, and the news stories were of course showing pictures of the starship Enterprise from Star Trek. But Shawyer's EMdrive was nowhere in that picture, and was an altogether separate and much less reported story on its own.

Then when the Eagleworks lab got involved in experimental testing to verify the Shawyer EMdrive concept (or Cannae drive, whatever) that's when suddenly the 2 stories began to merge, and speculation was put forth that the EMdrive was somehow a "Q-thruster" and then further that it was a "Warp Drive". Since the actual mechanism - if any - is unknown, what it is seems to depend on who's doing the speculating.

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