Author Topic: EM Drive Developments - related to space flight applications - Thread 7  (Read 1663848 times)

Offline Rodal

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Ok, would 3Mn worth of 'thrust' be in the ballpark range for the 'Not-so-sure-of-it' hypothesis?
Notsosureofit: make that 0.7mN @ 220Watts = 3.18 mN/kW

She does  not specify the mode shape, but she specifies the frequency: 2.45 GHz.  She seems to use the same dimensions that previously gave TE012 at this frequency.



 (please see: http://forum.nasaspaceflight.com/index.php?topic=39772.msg1527173#msg1527173)

Prof. Yang shows the importance of conducting a number of experiments, in order to get statistics:

Look at that thrust measurement result: that is an ugly reproducibility series of tests !
« Last Edit: 05/02/2016 03:04 am by Rodal »

Offline ThinkerX

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Another concern about Yang's latest test series.

What was the size and dimensions of the frustum?  I am remembering Doctor Rodal's occasional past comments that 'bigger is better' (paraphrase) when it comes to 'thrust.'  Are dimensions given anywhere in the paper that can be checked against the various spreadsheets?

Offline Tellmeagain

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Another concern about Yang's latest test series.

What was the size and dimensions of the frustum?  I am remembering Doctor Rodal's occasional past comments that 'bigger is better' (paraphrase) when it comes to 'thrust.'  Are dimensions given anywhere in the paper that can be checked against the various spreadsheets?

It was not mentioned at all... It seems the focus of this paper was the measure system. Only 2 pages out of 9 were used to talk about the measurement of the microwave thruster.

Offline Rodal

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To put this in context, once again the figure of merit in EM Drives has never been the force, but it is instead the force/PowerInput.  It is misleading to compare EM Drive experiments in terms of "force".

The threshold for Prof.Yang's latest 20 tests with a battery in a torsional pendulum (same instrument as used in Aerospace Institutional R&D for measurement of micro-thrust for spaceflight applications) was 3.18 mN/kW

These are the tests that have claimed more than 10 times that much > 31.8 mN that are now clearly nullified:

TEST                                              Minimum Claimed force/InputPower (mN/kW)  factor (x3.18)

Shawyer DEMONSTRATION TE012                    80                                                25
Shawyer FLIGHT THRUSTER  TE013                235                                               74   
YANG   TE012                                                900                                             283

Yang's previous claims are pulverized, as her previous claimed results were 283 times greater force/InputPower as she measured now with an uncertainty of 0.80

Similarly Shawyer's DEMONSTRATION and FLIGHT THRUSTER are amply nullified: claimed force/InputPower 25 and 74 times of what she measured now.


The disparity is so large, that one can also use 3 mN @ 14% uncertainty, which at 220 watts gives 13.64 mN/kW
and still all the above tests by Shawyer and Yang are nullified by large factors: exceeding 600%, and up to 6600% by Yang's latest tests.

TEST                                              Minimum Claimed force/InputPower (mN/kW)  factor (x13.64)

Shawyer DEMONSTRATION TE012                    80                                                6
Shawyer FLIGHT THRUSTER TE013                 235                                              17
YANG   TE012                                                900                                              66
« Last Edit: 05/02/2016 04:05 pm by Rodal »

Offline Rodal

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Another concern about Yang's latest test series.

What was the size and dimensions of the frustum?  I am remembering Doctor Rodal's occasional past comments that 'bigger is better' (paraphrase) when it comes to 'thrust.'  Are dimensions given anywhere in the paper that can be checked against the various spreadsheets?

It is easy to show that she did not run an EM Drive with significantly smaller dimensions to get smaller thrust/power.

The drawing of the EM Drive she used looks very similar to the previous one she used.  She does not seem to say anywhere that she run another EM Drive with much smaller dimensions.  The power she used (220 Watts) is too large for her to have been able to pump that power into a much smaller EM Drive.  In her previous tests, that she has now completely nullified, she used 150 Watts and 300 Watts, which is in the same range as what she run now.  For comparison, Hackaday Aachen team was able to pump only 0.04 watts into the Baby EM Drive.


Finally, the coup de grace is that she reports the natural frequency: 2.45 GHz, this is the same frequency she run previously.  If she would have run an EM Drive with smaller dimensions, the natural frequency would be higher.  Therefore the hypothesis that she run a smaller EM Drive is nullified.

 It looks like she run the same dimensions as before.
« Last Edit: 05/02/2016 02:43 am by Rodal »

Offline rfmwguy

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I see one thing that diminished sensivity besides 3 wire setup. The laser reflects off a mirror to a ruler. Months ago I tried something similar with poor results. A laser displacement sensor would have provided better accuracy. It would have been better to sample displacement at a far end of the platform not mid length imho

Additionally, glad to see an aperature coupling, but like tajmar, the waveguide couples widely into the frustum. This could provide a secondary cavity resonance, definitely will impact frustum resonance. Pehaps some modeling assuming wr340 is in order. An aperature much closer to the frustum would have been better, as evidenced by previous modeling of tajmars unit. A mid waveguide aperature allows overcoupling into the frustum itself...defeating the purpose I think.

Appears probe was used to measure maximum deflection. This could have lead to an overcoupled setting of the aperature as I believe happened with tajmar. Perhaps it is not to scale on the transmission line.

I see no vna sweeps of setup. If the paper has a chart, would be anxious to see it.

Offline oyzw

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So, if I am following this correctly, then...

Yang's results nullify any thrust from her devices greater than 3Mn - roughly on a par with other experiments.

The thrust *might* even be less than that, given the margin of uncertainty.  That margin might also allow for *slightly* larger results. 

Is that a fair assessment?  Seeking clarity here. 

But assuming 3Mn worth of thrust, give or take, is being produced somehow, then...

1 - does the EM Drive still stand in serious violation of CoE and CoM if the self contained version can produce 3Mn worth of thrust in a vacuum? 

2 - Would 3Mn worth of thrust be useful for spacecraft?
You have it basically. They moved from balance to torsion whose low end was 3mN. Don't think anything was measured, meaning it was nothing or below measurement threshold. 3 mN would be useful for spaceflight if it was this...all we know from her paper is it was below threshold of test stand and at around 275 watts of power. This was reported to be identical device tested originally. Coe and com are still unresolved. Dresden univ is offering phd project on emdrive, they will be moving forward as well.

I think I am responsible to clarify that I did not read from the paper that "This was reported to be identical device tested originally". It is only that in the new paper, they tested two settings, that power was on board and that power was supplied from outside. The device was identical in these two settings. It was not mentioned whether the device was the same as 2008 (and I think not; because in 2008 paper they used magnetron and in 2016 paper they used solid state...)
They had never used solid state!

Offline rfmwguy

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Nice catch on non SSD. Depending on power supply, there could be a lot of accoustic vibration on the platform from oldschool transformers in common kitchen power supplies. Shell can comment on the pulsed inverter types...don't know. Are we certain it was not a parametric amp/oscillator?

Offline Tellmeagain

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So, if I am following this correctly, then...

Yang's results nullify any thrust from her devices greater than 3Mn - roughly on a par with other experiments.

The thrust *might* even be less than that, given the margin of uncertainty.  That margin might also allow for *slightly* larger results. 

Is that a fair assessment?  Seeking clarity here. 

But assuming 3Mn worth of thrust, give or take, is being produced somehow, then...

1 - does the EM Drive still stand in serious violation of CoE and CoM if the self contained version can produce 3Mn worth of thrust in a vacuum? 

2 - Would 3Mn worth of thrust be useful for spacecraft?
You have it basically. They moved from balance to torsion whose low end was 3mN. Don't think anything was measured, meaning it was nothing or below measurement threshold. 3 mN would be useful for spaceflight if it was this...all we know from her paper is it was below threshold of test stand and at around 275 watts of power. This was reported to be identical device tested originally. Coe and com are still unresolved. Dresden univ is offering phd project on emdrive, they will be moving forward as well.

I think I am responsible to clarify that I did not read from the paper that "This was reported to be identical device tested originally". It is only that in the new paper, they tested two settings, that power was on board and that power was supplied from outside. The device was identical in these two settings. It was not mentioned whether the device was the same as 2008 (and I think not; because in 2008 paper they used magnetron and in 2016 paper they used solid state...)
They had never used solid state!

Yes they used solid state microwave source. On page 363, I underlined in red, "固态微波源" == solid state microwave source; "信号源" == signal source; "放大器" == amplifier


Offline oyzw

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So, if I am following this correctly, then...

Yang's results nullify any thrust from her devices greater than 3Mn - roughly on a par with other experiments.

The thrust *might* even be less than that, given the margin of uncertainty.  That margin might also allow for *slightly* larger results. 

Is that a fair assessment?  Seeking clarity here. 

But assuming 3Mn worth of thrust, give or take, is being produced somehow, then...

1 - does the EM Drive still stand in serious violation of CoE and CoM if the self contained version can produce 3Mn worth of thrust in a vacuum? 

2 - Would 3Mn worth of thrust be useful for spacecraft?
You have it basically. They moved from balance to torsion whose low end was 3mN. Don't think anything was measured, meaning it was nothing or below measurement threshold. 3 mN would be useful for spaceflight if it was this...all we know from her paper is it was below threshold of test stand and at around 275 watts of power. This was reported to be identical device tested originally. Coe and com are still unresolved. Dresden univ is offering phd project on emdrive, they will be moving forward as well.

I think I am responsible to clarify that I did not read from the paper that "This was reported to be identical device tested originally". It is only that in the new paper, they tested two settings, that power was on board and that power was supplied from outside. The device was identical in these two settings. It was not mentioned whether the device was the same as 2008 (and I think not; because in 2008 paper they used magnetron and in 2016 paper they used solid state...)
They had never used solid state!

Yes they used solid state microwave source. On page 363, I underlined in red, "固态微波源" == solid state microwave source; "信号源" == signal source; "放大器" == amplifier
YES,but  they don't have a cylindrical cavity body as a comparison test

Offline oyzw

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The characteristics of the Yang experimental data and the NASA data is similar, but is not very accurate

Offline oyzw

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Professor Yang has no negative 2008 experimental conclusion, but exclude external interference factors, also did not deny the objectivity of thrust to produce, but rather clear existing measuring conditions within the scope of uncertainty from the thruster in itself

Offline oyzw

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Another concern about Yang's latest test series.

What was the size and dimensions of the frustum?  I am remembering Doctor Rodal's occasional past comments that 'bigger is better' (paraphrase) when it comes to 'thrust.'  Are dimensions given anywhere in the paper that can be checked against the various spreadsheets?

It was not mentioned at all... It seems the focus of this paper was the measure system. Only 2 pages out of 9 were used to talk about the measurement of the microwave thruster.
She has never nullified emdrive

Offline MikeMcCulloch

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Dear NSF forum:

Just to stick my oar in briefly: this is just to point out that the new Chinese data are consistent with MiHsC.

Assuming these values: P=220W, Q=1531 (as in your wiki table) and cavity dimensions as before, MiHsC predicts 0.28 mN of thrust. Their sensitivity was quoted as 3 mN so this is below detection threshold.

Regards, Mike

Offline oyzw

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Dear NSF forum:

Just to stick my oar in briefly: this is just to point out that the new Chinese data are consistent with MiHsC.

Assuming these values: P=220W, Q=1531 (as in your wiki table) and cavity dimensions as before, MiHsC predicts 0.28 mN of thrust. Their sensitivity was quoted as 3 mN so this is below detection threshold.

Regards, Mike
YES

Offline Chrochne

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I do not understand so much optimism (from critics) here after the chinese new negative results. It means that we will be still using ancient technology of combustion to get to the space.

I at least hope they will end with their harsh language towards the people that try (and I mean they conduct tests) and not only offer criticism from the tables. Without tests there is no progress. Criticism is important, but it many times stoped progress as well.


Also this news from China can aslo mean that NASA EW may now recieve less funds to conduct further tests on this device. It means that now there is a possibility, that we will never know what is causing this "thrust".
« Last Edit: 05/02/2016 09:08 am by Chrochne »

Offline flux_capacitor

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Did Yang accounted for the change of mass hence inertia when removing or adding the power supply within the test apparatus? I mean:
1- Does including the power supply onto the torsion pendulum decrease its sensitivity due to the fact that the mass of the system is increased?
And:
2- Has a "dummy mass" of the same weight as the power supply + wires been added to the torsion pendulum when the power supply was external?

Offline Tellmeagain

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Professor Yang has no negative 2008 experimental conclusion, but exclude external interference factors, also did not deny the objectivity of thrust to produce, but rather clear existing measuring conditions within the scope of uncertainty from the thruster in itself

Yes She nullified her earlier work. See quoted text underlined in red. The translation is as follows,

"In 2008, In China, work (see reference 5,6,7,8, her own work --by me) had been done that used classic electromagnetic theory to interpret  the mechanism of microwave thruster[5,6], and used any-time balance thruster measure system[7,8] to measure thrust of the laboratory model of the microwave thruster. In China, though using any-time balance method enabled the observation of significant thrust of the microwave thruster, the force-bearing cavity in the experiment was separated from the microwave and power supply system. They were connected with flexible waveguide, and this connector under the heat generated in the working condition of the thruster would induce excessive force due to the heat induced deformation, interfering observation and measure of the normal thrust."

I tried my best to make sure the translation was word to word. This was her nullification of her 2008 work.

Edited to correct grammar.
« Last Edit: 05/02/2016 12:42 pm by Tellmeagain »

Offline Rodal

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I do not understand so much optimism (from critics) here after the chinese new negative results....
Scientists are interested in finding the truth about Nature.  As such people involved in R&D understand that nullification of prior wrong results is something to be happy about, as it clears the fog of ignorance.  A researcher explores several roads to a possible destination.  When a discovery shows that one is on the wrong road, that is something to be celebrated.  It would be foolish to persist on the wrong road leading to a precipice. 

It is also cruel to young people to tell them to stay on the wrong road leading to a precipice when you find out that they are on the wrong road.  Instead one should let them know that they are on the wrong road, and if necessary rescue them from wasting their life on the wrong road when there are so many other roads to be explored.

The sooner that we return to other unexplored roads the better, so that we can find the correct road.

That is how Edison explored thousand of roads to discovery.  And this is how so much progress was made in science and technology during the past hundreds of years.  After finding out you are on the wrong road: move on, there are countless other roads to explore. :)

I do not understand so much optimism (from critics) ...I at least hope they will end with their harsh language towards the people that try...
I have not used name calling towards people, I only address the technical issues.  You don't need to use names to refer to people that embrace Yang's new results, but if you want to use a good word to refer to them, you can refer to them as "objective people", or "people that seek the truth in Nature" instead of calling them "critics".  Scientists are not divided between "critics" and "believers".  Scientists are united in their search for the truth.

I do not understand so much optimism (from critics) here after the chinese new negative results. It means that we will be still using ancient technology of combustion to get to the space....
Why conclude this now ?

1) Dr. McCulloch has a message just above this one where he claims that his theory was predicting all along results that are consistent with Yang's new results rather than her previous claims.  Adopting for example McCulloch's theory, one is closer to fulfilling this technology by embracing Yang's new results which are (according to McCulloch) now consistent with McCulloch's theory rather than Yang's old results that were several orders of magnitude in disagreement with McCulloch's theories.

2) Yang's and Shawyer's extravagant claims were in contradiction with NASA's results, because they claimed orders of magnitude larger force/inputPower without a polymer insert while NASA's 2014 report showed that they obtained no significant thrust without a polymer insert even when increasing the power input by a factor exceeding 10 times.  Yang's nullification of her prior claims clear this issue. It does not affect at all the consistency of NASA's statements.  If anything they lend further credence to NASA's results that to get significant thrust/InputPower, a polymer insert is needed.  Thus Yang's new results may bring one back to the correct road: the road that NASA has been in, rather than the wrong road the road that Yang was in.

3) Even if it would turn out that NASA's results would eventually be falsified (which has not occurred yet) there are countless other spaceflight propulsion options.  Concerning
Quote
we will be still using ancient technology of combustion to get to the space
. There is no basis for the statement that the EM Drive is the only option available to replace combustion to get to space.
« Last Edit: 05/02/2016 12:44 pm by Rodal »

Offline Tellmeagain

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Did Yang accounted for the change of mass hence inertia when removing or adding the power supply within the test apparatus? I mean:
1- Does including the power supply onto the torsion pendulum decrease its sensitivity due to the fact that the mass of the system is increased?
And:
2- Has a "dummy mass" of the same weight as the power supply + wires been added to the torsion pendulum when the power supply was external?

She did not explicitly discuss dummy mass in section 5 and 6 which were related to the thruster tests. Comparing fig 16 and 19, we see that the battery was simply removed and no dummy mass was added. She calibrated for each settings in fig 17 and 20, respectively. Comparing the fitted lines between fig 17 and 20, we see that the weight of the system were different between the two settings.

 

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