Author Topic: EM Drive Developments - related to space flight applications - Thread 2  (Read 2137737 times)

Offline Notsosureofit

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Consider this, let's turn on the acoustic wave guide. Then close off the exit, closing off the Acoustic chamber.  The waves entering into the closed area in the chamber would be reflected back creating another set of set of interference harmonics and possibly destructive to the pattern of the first mode. But let's say I dampened the acoustic waves on the exit door, turning them into a pattern of heat? I see heat in the patterns of the thermal images even though they are RF dissipation in the copper.
So tell me, what is the difference in a system thinking this way? We still maintain the desired mode, whether acoustic or em wave.
Notsosureofit I think we are seeing the same thing but you have a much more eloquent way of stating it, I'm more nuts... well and bolts kinda gal.

In this case we are ignoring the dissipation by inputting constant power to make up for it.  The EM and (pressure) acoustic systems are similar in many ways.

When I try to do a thermodynamic calculation all bets are off.


FYI

Here we go:

http://physics.technion.ac.il/~msegev/publications/Maxwell_accelerating_beams.pdf

"For both TE and TM polarizations, the beams exhibit shape-preserving bending which can
have subwavelength features, and the Poynting vector of the main lobe displays a turn of more than 90"
« Last Edit: 05/23/2015 04:02 PM by Notsosureofit »

Online SeeShells

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Consider this, let's turn on the acoustic wave guide. Then close off the exit, closing off the Acoustic chamber.  The waves entering into the closed area in the chamber would be reflected back creating another set of set of interference harmonics and possibly destructive to the pattern of the first mode. But let's say I dampened the acoustic waves on the exit door, turning them into a pattern of heat? I see heat in the patterns of the thermal images even though they are RF dissipation in the copper.
So tell me, what is the difference in a system thinking this way? We still maintain the desired mode, whether acoustic or em wave.
Notsosureofit I think we are seeing the same thing but you have a much more eloquent way of stating it, I'm more nuts... well and bolts kinda gal.

In this case we are ignoring the dissipation by inputting constant power to make up for it.  The EM and (pressure) acoustic systems are similar in many ways.

When I try to do a thermodynamic calculation all bets are off.
I know the differences in acoustic pressure waves and EM waves gladly they both have similar phenomena of diffraction, reflection and interference and create standing waves in cavities.
I will be jazzed to see a thermodynamic calculation and no betting. ;)

Online Rodal

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...

I refer to Feynman:


"If it [theory] disagrees with experiment it is wrong."

Yet the trust of this forum seems to be to reject Shawyer and Chinese theory, which matches their experimental results, and seek some new theory outside physics when all that is needed is to listen to Shawyer and the Chinese and apply existing theory in a non conventional way.

For an engineer, seeking to model in excel what is happening as dimensions and frequency are varied, the blue sky theories on this forum provide no help, as none can take frustum dimensions and frequency and predict thrust per power applied. In fact most say there is NO THRUST.

However Shawyer's theory and equations does appear to model the thrust but those equations and explanations seem to be almost universally rejected.

Which going back to Feynman, with respect, is about as unscientific as it can get. Others claiming sloppy measurement protocols are just trying to find excuses to deal with reality and avoiding needing to accept the Shawyer and Chinese applications of current theory and thrust measurements are correct.

...
Concerning Feynman, I was educated in the same institution where he studied, under the same scientific principles and approach.  I performed experiments since I was a freshman (I was lucky that they had started the Undergrad Research Opportunity Program and immediately engaged in hybrid chemical rocket propulsion experiments) at that institution until I got my Ph.D.  Nobody at that institution performs experiments following a single researcher's publications as if they were a holy book.

Feynman's famous Lectures, and his professional life, teaches an approach to physical problems that is the diametrical opposite of following a single researcher as a Guru or a Prophet, whose publications have to be revered, obeyed and followed as a religious book. 

Concerning this thread its focus is on an objective, skeptical attitude trying to ascertain whether the experimental reports are an artifact or a real propulsion effect and if so whether they can be used for space applications, and also discussing those possible space propulsion applications.
« Last Edit: 05/23/2015 04:24 PM by Rodal »

Offline WarpTech

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...
However Shawyer's theory and equations does appear to model the thrust but those equations and explanations seem to be almost universally rejected.
...


I reject them simply because there are numerous, glaring errors in both math and logic, in all of Shawyer's papers. It shows he has a vague engineering understanding of waveguide physics, but has very little understanding of the physical mechanisms that governs "why" those principle can be applied. As I've said, in the end, his results that F1 - F2 > 0, is correct, he's not that far off and IMO he provides a useful approximation. It is the derivation of the Thrust and his concept of how it is achieved that is incorrect. I'm sorry it's taking me so long to write up this data, but life is not easy and neither is physics!

Todd
« Last Edit: 05/23/2015 04:06 PM by WarpTech »

Offline Notsosureofit

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FYI

Here we go:

http://physics.technion.ac.il/~msegev/publications/Maxwell_accelerating_beams.pdf

"For both TE and TM polarizations, the beams exhibit shape-preserving bending which can
have subwavelength features, and the Poynting vector of the main lobe displays a turn of more than 90"

"of the main lobe"

In our case the cavity keeps the shape from changing, so we see the force necessary to maintain the Poynting vector.

« Last Edit: 05/23/2015 04:12 PM by Notsosureofit »

Offline deltaMass

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Quote from: TheTraveller
However in both the Shawyer and Chinese test data thrust is generated, which should say to you that what Shawyer is saying about his theory and what the Chinese are saying about their theory is correct and your and other conventional application of theory is not correct.
Sure thing. What prevents you, therefore, from writing down those six numbers? Don't we want to look at how the predictions of Shawyer match the engineering truth?

Quote
Shawyer & Chinese conic frustums provide thrust that matches their equations predictions.
1. frustum big diameter & curvature
2. frustum small diameter & curvature
3. frustum vertical height
4. operating frequency
5. predicted thrust
6. measured thrust

(no dielectric please, and preferably flat ends)
« Last Edit: 05/23/2015 04:25 PM by deltaMass »

Online SeeShells

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Yet the trust of this forum seems to be to reject Shawyer and Chinese theory, which matches their experimental results, and seek some new theory outside physics when all that is needed is to listen to Shawyer and the Chinese and apply existing theory in a non conventional way.

For an engineer, seeking to model in excel what is happening as dimensions and frequency are varied, the blue sky theories on this forum provide no help, as none can take frustum dimensions and frequency and predict thrust per power applied. In fact most say there is NO THRUST.

Quote
Follow the data, theory be dammed
As an engineer I question everything, I look at everything and I mean everything. I look at my coffee cup and I not only see a cup but see how it was made, I look at a radio and see the inside workings of waveforms getting amplified, rectified and how the speaker.  It is the way I think. Yes Shawyer and the Chinese have ideas on how this works and so I question it, it is what I do and so do others, It's how we are built. It's not to be meant to degrade the honest work they have done or discredit them or you in any way. I respect you and them and anyone here who has the dream.

I remember in 1959 on a cold October night watching a twinkling light in the sky and knew even then the world was going to change forever, it was Sputnik. That era was started by people who followed the data, those who dreamed, those who built, those who cheered, but we all in one way or another saw the twinkling light.

Shell

Offline Notsosureofit

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FYI

Here we go:

http://physics.technion.ac.il/~msegev/publications/Maxwell_accelerating_beams.pdf

"For both TE and TM polarizations, the beams exhibit shape-preserving bending which can
have subwavelength features, and the Poynting vector of the main lobe displays a turn of more than 90"

"of the main lobe"

In our case the cavity keeps the shape from changing, so we see the force necessary to maintain the Poynting vector.

Added:  in the conclusions...

". To complete
the picture, future work should study the possibility of 3D
accelerating beams, including those with trajectories that
do not lie in a single plane. In practical terms, this work
brings accelerating beam optics into the subwavelength
regime, through the less-than-wavelength features of our
solutions, facilitating higher resolution for particle
manipulation."

Offline phaseshift

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Yet the trust of this forum seems to be to reject Shawyer and Chinese theory, which matches their experimental results, and seek some new theory outside physics when all that is needed is to listen to Shawyer and the Chinese and apply existing theory in a non conventional way.

For an engineer, seeking to model in excel what is happening as dimensions and frequency are varied, the blue sky theories on this forum provide no help, as none can take frustum dimensions and frequency and predict thrust per power applied. In fact most say there is NO THRUST.


@TheTraveller,

There are different disciplines at work here.  They do what they know and understand and you do what you know and understand.  I myself am a software engineer (35 years) and likewise I have a different approach to get my head around everything I'm reading and learning. We are all heading in the same general direction just along different paths - this is a good thing.

Accept the differences of the different disciplines, they are necessary. :)
"It doesn't have to be a brain storm, a drizzle will often do" - phaseshift

Offline rfmwguy

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...
However Shawyer's theory and equations does appear to model the thrust but those equations and explanations seem to be almost universally rejected.
...


I reject them simply because there are numerous, glaring errors in both math and logic, in all of Shawyer's papers. It shows he has a vague engineering understanding of waveguide physics, but has very little understanding of the physical mechanisms that governs "why" those principle can be applied. As I've said, in the end, his results that F1 - F2 > 0, is correct, he's not that far off and IMO he provides a useful approximation. It is the derivation of the Thrust and his concept of how it is achieved that is incorrect. I'm sorry it's taking me so long to write up this data, but life is not easy and neither is physics!

Todd

Well said Todd, for I have read and watched Shawyers papers/presentations and needed more of an explanation. Guess if it were cut & dry, this thread would have stopped long ago.
« Last Edit: 05/23/2015 04:54 PM by rfmwguy »

Offline Mulletron

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Brand new. Interview with the inventor of EmDrive. Good info in there.

« Last Edit: 05/23/2015 05:00 PM by Mulletron »
Challenge your preconceptions, or they will challenge you. - Velik

Offline Chris Bergin

This is probably a good place to end this thread, as noted was the plan today :)

Thread 3!
http://forum.nasaspaceflight.com/index.php?topic=37642.0

Farewell Thread 2, and we thank you.

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