Author Topic: EM Drive Developments - related to space flight applications - Thread 8  (Read 1412638 times)

Offline Star One

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Maybe I am misunderstanding but are some of you saying that the limitations on the EW budget may have hampered their paper and the results presented therein?

It certainly has allowed the sceptics to have a field day with it I would say.
« Last Edit: 11/25/2016 07:44 am by Star One »

Online meberbs

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While sims like COMSOL and FEKO do show the increasing guide wavelength as the diameter decreases, they don't have the ability, as far as I know, to model the drop in the radiation pressure as the guide wavelength increases.
That is entirely backwards. The sims are perfectly capable of providing a way to calculate the forces on each end plate and the sidewalls, and they all will show a larger force on the large plate than the small one, balanced by the force on the sidewalls.

While the distance between the nodes of the standing wave increases towards the small end, "distance between nodes of a standing wave" is not the definition of guide wavelength, and is only meaningful at discrete points, not in the continuously varying way that you use guide wavelength. The models can't provide an answer when you don't have a fully defined question, and you have never properly defined guide wavelength in this context.

Offline TheTraveller

While sims like COMSOL and FEKO do show the increasing guide wavelength as the diameter decreases, they don't have the ability, as far as I know, to model the drop in the radiation pressure as the guide wavelength increases.
That is entirely backwards. The sims are perfectly capable of providing a way to calculate the forces on each end plate and the sidewalls, and they all will show a larger force on the large plate than the small one, balanced by the force on the sidewalls.

While the distance between the nodes of the standing wave increases towards the small end, "distance between nodes of a standing wave" is not the definition of guide wavelength, and is only meaningful at discrete points, not in the continuously varying way that you use guide wavelength. The models can't provide an answer when you don't have a fully defined question, and you have never properly defined guide wavelength in this context.

Good to know the sims can model the forces. Care to do that and share the data? Plus be sure the equations used to calculated the radiation pressure are compatible with the equations of Cullen.

Both Roger and I created Excel spreadsheets that modeled the tapered waveguide as a series of constant diameter waveguides stacked end on end. The results of Roger's and my spreadsheet can calculate the resonant freq in just about any mode, freq and frustum design to around 1% accuracy.

As Roger tells it in the Experimental EmDrive report:

Quote
Finally the overall electrical length of the thruster must be a multiple of e/2 where e is the effective wavelength of the thruster.

This effective wavelength will equate to different values of physical length throughout the waveguide assembly.

The overall geometry was defined by building a mathematical model of the thruster based on an Excel spreadsheet.

The physical length was divided into 0.5mm sections and the guide wavelength calculated for each section. The electrical length for that section was calculated and the summation of the section electrical lengths calculated.

Thus variations of diameters, lengths and er could be modelled, with the target of achieving an overall electrical length equal to ne/2.

The model also allowed the operation to be modelled in TE11 and TE12 modes, the nearest unwanted modes. The design was optimised to avoid the possibility of any unwanted mode operation.

Roger used a 0.5mm section length. My spreadsheet divides the frustum length axis into 65,000 very small sections.

As the radiation pressure drops much faster than the diameter drop, going from big to small, it is not possible for the sum of all the forces to equal zero.

Maybe instead of wasting time repeatedly stating why it can't work, maybe try to come up with a theory that fits the observed data?

As Galileo said to his disbelievers: "and yet it moves"
« Last Edit: 11/25/2016 08:39 am by TheTraveller »
It Is Time For The EmDrive To Come Out Of The Shadows

Offline wavelet

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Dear friends, it is well known that electromagnetic waves can produce propulsion (solar sails, laser/mirror propulsion etc) , but the already experimented and measured effect is very tiny.
Consider the FACTS:
After very accurate tests it has been found that the so called em drive works in a vacuum.
There is a dielectric inside the cavity and it improves the performances.
Now we need to understand why the em drive works and the role of the dielectric. This is needed to further improve the technology.
Nearly no em wave can escape the cavity. We need to understand the nature of the massive particles that escape the cavity and provide the propulsion.
We have few choices here: neutral massive particles, gravitational waves.
We could exclude neutral particles, because there is no nuclear reaction in the cavity producing neutrons, nor there is a neutrino generator inside and no living being has been harmed.
What remains is gravitational waves, so please give a look at the other thread. Including the references.
Thank you for your attention.

 
« Last Edit: 11/25/2016 07:04 pm by wavelet »

Offline therealjjj77

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I wasn't saying that anti-matter had the property of anti gravity.  Rather I was suggesting the possibility that if anti-matter had the property of reverse time, that it would reverse the positive charge on anti-matter to behave as if it were a negative charge, or opposite of its counterpart.  I was then suggesting that the polarization of the property of time in anti-matter and matter in the polarized QV could then be responsible for what we perceive as gravity.  I was thinking of anti-matter as having positive stored energy if it is separated from matter in that if it comes back to matter, the electric field generated disturbs the quantum vacuum and makes the light seen from the annihilation effect.  The light being the polarization of the QV. 

I don't think time works in this fashion. Time does not have a reverse per se. That's not to say that anti-matter will not mirror the opposite action of matter when formed(as in hurling in the opposite direction with an opposite spin), but it would do so in a forward time. Usually this comes from a misunderstanding of the Theory of Relativity. You are thinking in the right direction, though, to look for a process causing gravity and not just the mere presence of mass. I have just submitted an article for publishing on this topic and will post it here once the article is published.

I found some interesting information on a cern link that touches on some history.  I was excited to see that Richard Feynman may have thought of anti-matter as traveling back in time.  It might be connected to the Wheeler-Feynman theory and the Feynman diagrams.  I'll probably have to look more into it.  Here is the link: http://cds.cern.ch/record/294366/files/open-96-005.pdf

This may also be connected and I suspect it appears to suggest dark matter as anti matter in another dimension where space time flows out of that matter and pulls our space time in leading to gravity but from another dimension?  I could be wrong on this as I still have to read this article.  I suspect it is what it is about because it was something that I had considered previously.  Link is here: http://arxiv.org/abs/physics/9812021  They mention Feynman and reverse time for anti-matter also!  Mmmm, not quite what I expected I suppose.

How on earth did we run into metaphysics? Without testable predictions, theories and ideas on the mechanics of the Universe are worse than useless.  :o

We are in a severe drought of experimental data to discuss.  ;D

I suppose I found it exciting because it got my mind thinking in a way I hadn't yet which was to make the connection of time reversal in anti-matter and that inducing gravity and relativity.  Not sure how solid that foundation might be yet but it seems there may already be some structure for it.  I was feeling the need to better understand the quantum vacuum if we are going to speculate we can push off of it.

As promised, here is the article.

So following this theory stated in the attached, what I believe is happening in the EM Drive is that there are more energy -> matter conversions happening on the broader side. These energy -> matter conversions result in more space being created on the broader side of the EM drive, which produces the measurable thrust.

If energy -> matter conversions result in space being created and the converse results in space being consumed, it is the simplest explanation which resolves the accelerated expansion of the Universe, explains gravity, and predicts phenomenon like what occurs in the EM drive. It also is a theory which can be used for bypassing the speed of light by manipulating space instead of traveling through it. Cheers
« Last Edit: 11/26/2016 04:05 pm by therealjjj77 »

Offline rq3

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« Last Edit: 11/25/2016 12:25 pm by rq3 »

Offline Rodal

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On the issue of NDA's and secrecy of NASA's Eagleworks on the Warp Drive and the EM Drive, that has been brought up in this forum in the past, some times without actual facts, here is an actual response from NASA JSC PAO (Johnson Space Center Office of Public Affairs) to Keith Cowing's questions at SpaceRef, from 3.5 years ago (Posted April 12, 2013):

http://spaceref.com/nasa-hack-space/propulsion/clarifying-nasas-warp-drive-program.html

What follows is verbatim from the above article except the explanatory note in brackets "[]" I insert below:




Did Harold White sign NDAs as an individual or as a NASA civil servant? Who did he sign these NDAs with?

White has not signed any NDAs. The article has it backwards.

[NOTE: This is in reference to the statement "He (White) explains that he has signed nondisclosure agreements that prevent him from revealing the particulars. " by Konstantin Kakaes  April 1, 2013, in  http://www.popsci.com/technology/article/2013-03/warp-factor?single-page-view=true]

In order for the Popular Science author to get briefed on the referenced technology, he would need to sign an NDA with the government as the noted technology has an invention disclosure. An NDA is the mechanism to protect the IP content, but still allow access to interested parties for consideration.

Is Harold White's Eagleworks advanced propulsion/warp drive research considered Sensitive But Unclassified (SBU) by NASA?

No, but some of the technology has invention disclosures in the NASA system, and this information is considered SBU. It still may be accessed by interested parties in industry, academia and government with the use of an NDA.

Is Harold White receiving DARPA or other external funding while working at NASA on his advanced propulsion/warp drive research?

Not at this time.

Does NASA have Space Act Agreements or MOUs with external entities related to White's advanced propulsion/warp drive research? If so who are these agreements with?

There are current discussions on a SAA and CRADA with industry partners, but specifics on these agreements are still in negotiation and are SBU.

How much has NASA already spent on this project? How much does it intend to spend on this project? Where do the funds for Eagleworks and White's advanced propulsion/warp drive research come from? JSC? HQ?

The scope and scale of this project is small and commensurate with a university effort. Most of the equipment was pulled from storage to minimize capital procurement. Total procurement to implement the warp field interferometer is ~$50k. The funding comes from JSC.

Was this advanced propulsion/warp drive research submitted to peer review at NASA JSC? At NASA HQ? Who made the funding decision(s)?

Yes, all projects no matter the scope or scale are put through the competitive process, whether through local JSC competitive processes, or more broad agency competitive processes. In addition, Dr. White has written a peer-reviewed paper on his research that will be published in the Journal of the British Interplanetary Society

Are progress reports made by White as to the progress that his research team has made on advanced propulsion/warp drive research? Are these reports available to the public?

White interfaces with the broader scientific and technical community through technical conferences and scientific journals. When milestones are reached, these results will be communicated with the broader community through the most appropriate and timely mechanism to facilitate distribution of the findings.

What scientific publications have White and his team made on advanced propulsion/warp drive research?

Talks and Publications on Space Warps to date:

- White, H., Warp Field Mechanics 101, Journal of the British Interplanetary Society, accepted 2013.
- Physics Colloquium on Warp Field Mechanics requested by Dickinson College, 2013.
- Encore of Warp Field Mechanics 102, technical presentation requested by SpaceVision 2012, Buffalo, NY 2012.
- Warp Field Mechanics 102, technical presentation given at the 100 Year Starship Symposium, Houston, TX, 2012.
- Encore of Warp Field Mechanics 101, technical presentation requested by AIAA, Houston Chapter, Gilruth Center, Houston, TX, 2011.
- Warp Field Mechanics 101, technical presentation given at the 100 Year Starship Symposium, Orlando, FL, 2011, available at: http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20110015936_2011016932.pdf
- Successful defense of published paper "A Discussion of Space-Time Metric Engineering" as part of Ph.D. candidacy process in Physics at Rice University 2007.
- White, H., E. W. Davis, The Alcubierre Warp Drive in Higher Dimensional Spacetime, in the proceedings of Space Technology and Applications International Forum (STAIF 2006), American Institute of Physics Conference Proceedings, Melville, New York, 2006.
- White, H., A Discussion of Space-Time Metric Engineering, General Relativity and Gravitation Journal, November 2003."
« Last Edit: 11/25/2016 02:22 pm by Rodal »

Offline Star-Drive

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...

"Shouldn't the time process for a degradable Quantum Vacuum be many orders of magnitude faster?"

Agreed, but IMO the time delays observed in the fall 2015 EW lab's in-vacuum testing are specific to the ICFTA design interactions with the EW torque pendulum and are not inherent in the degradable QV interactions.  The EW lab's Dec 2014 split system in-vacuum test had much more prompt force turn-on and turn-off responses as demonstrated in figure 12 in the AIAA/JPP paper and my spring 2015 postings here a NSF.com.  I've attached a couple of slides from this spring 2015 time period as a reminder to all.

Best, Paul M.

I remember those graphs because the reverse response was so much less than the forward response.   If I'm not mistaken that was also when your group started to mitigate the Lorentz error.    My conclusion then and now of the reverse graph is that it is due to magnetic interaction.   It is the only "thrust" waveform that has the characteristics of a second order step response.  There is a fast rise/fall time and an overshoot with ringing.   That type of response curve has not been seen again in your results.   The second graph is a first order step response; ie:thermal.   In a vacuum or low pressure atmosphere the time constant is longer.   It would be useful to see a lot more data, even families of plots.   For example what would the plots look like if the pressure was stepped down by powers of ten (logrithmically), with everything else the same?   My guess is the time constant of the step response would increase as the pressure decreased.   Another experiment I have been asking all the em-drive dy people to do is to heat up the Copper cone with resistive heaters and collect data as if it was an RF input.   No one has done that yet.    I'm sure the EW team has the resources to do this.   

The more things you change in an experimental setup the more information you get from your experiments.   For example what would happen if the EW team redesigned the mounting hardware that holds the Copper cone on the TP arm.   If they could design it so that the CG vs displacement test using the 10 gram weight no longer caused a significant change in displacement how would that affect later tests?   It would be interesting to see.   I know the EW team has done excellent work and are only interested in finding the truth so I assume they will eventually do some of the things I have suggested.

Zen-in: Please remember that I no longer work at the Eagleworks (EW) Lab and I do not have access to this EW copper frustum test article any longer.  I was also working under the direction of Dr. White who did not give me the freedom to pursue a number of tests and thruster optimizations I would have liked to have pursued in the latter part of 2014 till the time I left the EW lab, so a lot of the tests you suggest were thought of, but could not be pursued due to the demands of upper NASA/JSC management.  That will change when I get into my new home lab that I will control.

Best, Paul M.

Offline Star-Drive

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Quote
As will be discussed in more detail at the end of the section on slope filtering, in order to run the test article in a fully integrated configuration, the torsion pendulum is operated in a highly loaded configuration, which results in slower displacement rates for the torsion pendulum when an impulsive force is applied.
Perhaps nudging the pendulum with a known force could let us get a time to use in place of "slower"?

If there only were some kind of, I don't know, calibration pulse.
In all seriousness... this is pretty bad. I use the calibration pulse to determine the time constant of the pendulum as 4 seconds, and get no thrust in their latest graphs. What ever was responding to power rapidly is now gone.

Yes, there's something odd at 17..20 s , but then, there's great many components being heated non-uniformly. Some may even be undergoing quasi-phase changes (plastics have a glass transition temperature). Some may be warping until they mechanically come in contact with another component.

All:

This will be my last post of the day.  The EW Integrated Copper Frustum Test Article (ICFTA) had metallic and plastic components with competing and non-linear thermal expansions and contractions when heated, see previous posted slides on this topic, that when driving the torque pendulum's center of gravity shifts, blurred the impulsive response of this test article in time, dependent on the magnitude of the impulsive force.  For me, it is fully explained in the text of the JPP report, so please go back and read it this section again until it hopefully makes sense to you.

Best,  Paul M.

Dear Paul,

Do you have additional data for us about the dynamic behavior of the torque pendulum?
Without this, the observed responses are difficult to judge. The torsional constant of the flexure bearings must be quite big, given the rather fast response to a step function. The moment of inertia must be more than 6 kg.m^2, I guess (cooling block 5 kg, frustum, amp, counter weight...).
Has the frequency response been measured? And what is the damping factor?
I think it is really necessary to know this for a system like this.

Thanks,
Peter

Peter:

Find attached two slides with a set of electrostatic fin generated calibration force pulses for both the Eagleworks (EW) split and integrated copper frustum test configurations.  I'll let you figure out the rest of the analytical data you are seeking with one other input.  The Eagleworks B15 torque pendulum (TP) arm lenghtwas 24.00" long with a ~16.0" forearm and ~10.0" aft-arm lengths from the TP torsion bearings.

Best, Paul M.
Star-Drive

Offline otlski

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Mr March,

From the attached two images and the accompanying pdf, would you point us toward the flexure pivot that might closely match what EW used?  Thanks.

Offline WarpTech

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List of unaddressed or missing issues from the recent EW paper via a poster on Reddit.

https://drive.google.com/file/d/0B6juR48k_XoTREUxc1QycWxwZ2M/view

See what you think?

Several relevant points were made, but none that couldn't be answered. Either by data that was left out or by a rerun of the test bed.

Personally I've wondered why a TM212 mode was pushed? When clearly the TE012 mode provided a >5 fold indication of thrust when run. I know now the TE012 mode was hard to keep tuned because of close by resonate modes. Although cost wise a frustum of different dimensions that would have a TE012 or 013 that was sufficiently isolated from accompanying close modes is not that costly or challenging engineering wise.

Dr. White IMHO should have followed the data and brought the thrust levels out from the noise. You could have been recording >600uN instead of the lower 128uN.  I might assume that the reason was is that Dr. White was pushing his theory of Virtual Particle generation and that a TM mode used in particle accelerators might be the main reason why. TE modes won't fit his theory or throw a monkey wrench into theory.
No need to comment on this because it's mostly speculation on my part.

Shell

The mode frequencies were too close together, and difficult to lock on to. I believe this can be avoided by using a larger cone half-angle. The small angle puts all the frequencies very close together, a larger angle separates them.

Offline WarpTech

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The 3 boxes are sized such that the diagonal lines are ~ equal length. This illustrates how the dispersion is different for wavelengths along the z axis versus those perpendicular to it.

Food for thought Time ... again   :(

I love those sims charts COMSOL etc.  But, noting being perfect....

What would be the perfect sims softwares?  The “perfect” sims softwares would be the ones where on the graph we see a big huge arrow saying “thrust”.  O.K., we are not there yet! But, could we get a wee bit closer to that perfect chart? From complex modes, swirling electric and magnetic fields, and energy density we are supposed to guess which way the whole thing is going?

Would it be possible (remember, I don’t know what I’m talking about really) to go to some higher level computation in order to get closer to this big arrow? For example, Warptech’s theory is about a differential in the rate of power dissipation. Could this rate be computed ... for, say, a known working set of modes and compare it with the non working modes or settings to see if any significant differences are showing up on the graph; a better visual on a notable asymmetry of sort.. some clues!!!

... Just saying...

It could, but the cost of the software to do it is out of my price range, and I'm not confident in my ability to write my own code in MathCAD. If someone knows how to program it into MathCAD, that would be ideal.

Can FEKO or COMSOL spit out the programmed equations and variables that it is running? Maybe I could just import those into MathCAD. (I have MathCAD.)

Offline WarpTech

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The 3 boxes are sized such that the diagonal lines are ~ equal length. This illustrates how the dispersion is different for wavelengths along the z axis versus those perpendicular to it.

Todd - Thanks for this visual aid - it goes a long ways to help some of us laymen understand your hypothesis.  My initial observation was, under your theory, could this same effect be created by taking three (or more) independent cylinder cavities, each having a varying radius and depth so they resonate at similar modes, and stacking them onto one another in a taper fashion?  (To clarify, when I say independent, I mean fully enclosed with separate RF sources)

I would think that depending on the skin depth and material of each cavity, it would be possible to thermally integrate them, so that dissipation could be managed/amplified in interesting ways. 

Anyways, just a quick observation and thought experiment that probably betrays my understanding more than anything :o, but IMO, the answer to this could help clarify what configurations your theory would operate in.

Best regards to everyone who contributes to this effort - it is truly amazing to witness no matter the outcome, now back to lurking ;).

I don't think 3 fully independent cylinders will work because the primary goal is to have the internal stored mass-energy "flowing" from one end to the other and not coming back. Such a combination would just be 3 independent MW heaters.

Offline WarpTech

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All I wanted to do was show that the resonant frequency remains constant, despite the fact that there is dispersion happening in each orthogonal component of the wave. Shawyer's model is based on the dispersion along the z-axis, the "guide wavelength" while @Notsosureofit's model is based on dispersion of the frequency as a whole, which it is assumed behaves like the dispersion of the polar wavefront. I would like to reconcile that the two dispersive forces cancel each other out, leaving ONLY dissipation as the primary component of thrust. :)
Todd,
due to EM-field energy to net force it's quite logical that there should be a dissipation component exists in this regard. Better an energy transfer to the thrust component. Pure dissipation, because of resistive losses is also present in a cylindrical conductive cavity, whats needed is a gradient as you describe in your equations, therefore I am with you at this point. :)

Thanks! In this TE013 mode, we can model it as 3 separate oscillators, all with the same resonant frequency. Based on the wavelengths, the big end would have higher inductance (L), higher resistance (R) and lower capacitance (C). The small end would have lower inductance, lower resistance and higher capacitance. The one in the middle, would be well... in the middle of the range for each component value.

If we use the definition of the decay time as tau ~ L/R. If properly designed there will have 3 different values, hence there is a gradient in the decay time as the energy is dissipated. Charging and discharging should generate a thrust due to this gradient.

I'm just not sure how to determine the momentum of the magnetic flux that is escaping through the voltage drop in the metal.

Using standard microwave engineering equations for guide wavelength vs mode vs freq vs diameter, the increasing guide wavelength can be plotted big to small end. As seen, the plot is not linear and the guide wavelength starts to get really only as the small end approached cutoff.

Then using Cullen's equation for radiation pressure vs guide wavelength, the decreasing radiation pressure can also be plotted and again is is not linear with decreasing diameter not is it linear with increasing guide wavelength.

While sims like COMSOL and FEKO do show the increasing guide wavelength as the diameter decreases, they don't have the ability, as far as I know, to model the drop in the radiation pressure as the guide wavelength increases.

Sure they do! What you're missing TT, is that while the "guide wavelength" has this behavior per your graph, the wavelength orthogonal to it, reflecting off the sidewalls would have the opposite graph, where the radiation pressure goes up as the wavelength goes down, in the same manner. Shawyer has a "logical" reason why there is no force on the sidewall, but his logic is flawed and not based soundly on Maxwell's equations. There is most certainly pressure on the sidewalls, and that pressure increases toward the small end. Swap blue and purple on your graph.

Online SeeShells

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Maybe I am misunderstanding but are some of you saying that the limitations on the EW budget may have hampered their paper and the results presented therein?

It certainly has allowed the sceptics to have a field day with it I would say.

With what you did receive it seems that you were able to show over the last 5 years, tests producing tantalizing data. Many here (the press sure knows it) must realize the potential advantage of a propelentless EM engine and have to wonder why it wasn't aggressively pursued with a little more funding and resources.

With a 18.5 billion dollar budget NASA should have earmarked more than they did, NASA surely could afford to do it right and put the question to bed, we all can take advantage of it, if it does.

Shell

Offline Rodal

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The 3 boxes are sized such that the diagonal lines are ~ equal length. This illustrates how the dispersion is different for wavelengths along the z axis versus those perpendicular to it.

Food for thought Time ... again   :(

I love those sims charts COMSOL etc.  But, noting being perfect....

What would be the perfect sims softwares?  The “perfect” sims softwares would be the ones where on the graph we see a big huge arrow saying “thrust”.  O.K., we are not there yet! But, could we get a wee bit closer to that perfect chart? From complex modes, swirling electric and magnetic fields, and energy density we are supposed to guess which way the whole thing is going?

Would it be possible (remember, I don’t know what I’m talking about really) to go to some higher level computation in order to get closer to this big arrow? For example, Warptech’s theory is about a differential in the rate of power dissipation. Could this rate be computed ... for, say, a known working set of modes and compare it with the non working modes or settings to see if any significant differences are showing up on the graph; a better visual on a notable asymmetry of sort.. some clues!!!

... Just saying...

It could, but the cost of the software to do it is out of my price range, and I'm not confident in my ability to write my own code in MathCAD. If someone knows how to program it into MathCAD, that would be ideal.

Can FEKO or COMSOL spit out the programmed equations and variables that it is running? Maybe I could just import those into MathCAD. (I have MathCAD.)
FEKO uses the Boundary Element Method (which they call by a different name because the developer came from the EE side instead of numerical analysis) while COMSOL uses a Galerkin form of the Finite Element Method.

The answer is a resounding NO on both of your questions.

Both FEKO and COMSOL are proprietary codes.  They are black boxes to users.  COMSOL does not even have proper theoretical manuals (unlike more theoretically grounded codes like ABAQUS and ADINA for example).
Does not give me a good feeling,do their users care about the theoretical basis for the code they are using? Why don't they have a theoretical manual?.  So no, you cannot get their source code or equations except on some vague terms on their Users Manuals (you can get much more detail on a book on Finite Element Analysis or the Boundary Element Method)..

On MathCad being able to do this well.  You need a code that can do Finite Element analysis, being able to effciently invert large matrices. Mathcad FE:   http://www.ptc.com/cad/simulation-software/fea

It does not even have an electromagnetic module.

not on the same level as FEKO and COMSOL
« Last Edit: 11/25/2016 04:59 pm by Rodal »

Offline WarpTech

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The 3 boxes are sized such that the diagonal lines are ~ equal length. This illustrates how the dispersion is different for wavelengths along the z axis versus those perpendicular to it.

Food for thought Time ... again   :(

I love those sims charts COMSOL etc.  But, noting being perfect....

What would be the perfect sims softwares?  The “perfect” sims softwares would be the ones where on the graph we see a big huge arrow saying “thrust”.  O.K., we are not there yet! But, could we get a wee bit closer to that perfect chart? From complex modes, swirling electric and magnetic fields, and energy density we are supposed to guess which way the whole thing is going?

Would it be possible (remember, I don’t know what I’m talking about really) to go to some higher level computation in order to get closer to this big arrow? For example, Warptech’s theory is about a differential in the rate of power dissipation. Could this rate be computed ... for, say, a known working set of modes and compare it with the non working modes or settings to see if any significant differences are showing up on the graph; a better visual on a notable asymmetry of sort.. some clues!!!

... Just saying...

It could, but the cost of the software to do it is out of my price range, and I'm not confident in my ability to write my own code in MathCAD. If someone knows how to program it into MathCAD, that would be ideal.

Can FEKO or COMSOL spit out the programmed equations and variables that it is running? Maybe I could just import those into MathCAD. (I have MathCAD.)
FEKO uses the Boundary Element Method (which they call by a different name because the developer came from the EE side instead of numerical analysis) while COMSOL uses a Galerkin form of the Finite Element Method.

The answer is a resounding NO on both of your questions.

Both FEKO and COMSOL are proprietary codes.  They are black boxes to users.  COMSOL does not even have proper theoretical manuals (unlike more theoretically grounded codes like ABAQUS and ADINA for example).
Does not give me a good feeling, as a code that does not have a good theoretical manual means that their users do not care that much about the theoretical basis for the code they are using.  So no, you cannot get their source code or equations except on some vague terms on their Users Manuals (you can get much more detail on a book on Finite Element Analysis or the Boundary Element Method)..

On MathCad being able to do this well.  You need a code that can do Finite Element analysis, being able to effciently invert large matrices. Mathcad FE:   http://www.ptc.com/cad/simulation-software/fea

It does not even have an electromagnetic module.

not on the same level as FEKO and COMSOL

That would be a steep learning curve for me. Also, PTC's CREO does not do EM FEA. I had already looked at this. MathCAD can do whatever it's programmed to do, but programming an FEA from first principles would not be easy.
« Last Edit: 11/25/2016 04:51 pm by WarpTech »

Offline Star-Drive

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Mr March,

From the attached two images and the accompanying pdf, would you point us toward the flexure pivot that might closely match what EW used?  Thanks.

Find the EW Lab's Riverhawk torsion bearing specification sheet below.  Two of these Riverhawk bearings were used to support the torque pendulum 24.00" long aluminum arm.  However we ended up with 410 stainless steel for these bearing blocks when we should have used 316 stainless steel or even alloy 260 brass for the bearing halves to minimize the possibility of post installation magnetization of the blocks.  De-gaussing is such a pain to do...

Best, Paul M.
Star-Drive

Offline Rodal

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...

That would be a steep learning curve for me. Also, PTC's CREO does not do EM FEA. I had already looked at this. MathCAD can do whatever it's programmed to do, but programming an FEA from first principles would not be easy.
If you ever want to spend the time doing this, the easiest route would be to use MEEP from MIT.

Meep is free, and that was precisely its purpose: it is open source, so that students can develop their own modules and equations to solve new problems.  Meep is not meant to be used as a black box, but precisely as an open code.

Meep uses the Finite Difference method, which is much simpler than FEM or BEM.

« Last Edit: 11/25/2016 05:25 pm by Rodal »

Offline zellerium

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The 3 boxes are sized such that the diagonal lines are ~ equal length. This illustrates how the dispersion is different for wavelengths along the z axis versus those perpendicular to it.

Food for thought Time ... again   :(

I love those sims charts COMSOL etc.  But, noting being perfect....

What would be the perfect sims softwares?  The “perfect” sims softwares would be the ones where on the graph we see a big huge arrow saying “thrust”.  O.K., we are not there yet! But, could we get a wee bit closer to that perfect chart? From complex modes, swirling electric and magnetic fields, and energy density we are supposed to guess which way the whole thing is going?

Would it be possible (remember, I don’t know what I’m talking about really) to go to some higher level computation in order to get closer to this big arrow? For example, Warptech’s theory is about a differential in the rate of power dissipation. Could this rate be computed ... for, say, a known working set of modes and compare it with the non working modes or settings to see if any significant differences are showing up on the graph; a better visual on a notable asymmetry of sort.. some clues!!!

... Just saying...

It could, but the cost of the software to do it is out of my price range, and I'm not confident in my ability to write my own code in MathCAD. If someone knows how to program it into MathCAD, that would be ideal.

Can FEKO or COMSOL spit out the programmed equations and variables that it is running? Maybe I could just import those into MathCAD. (I have MathCAD.)
FEKO uses the Boundary Element Method (which they call by a different name because the developer came from the EE side instead of numerical analysis) while COMSOL uses a Galerkin form of the Finite Element Method.

The answer is a resounding NO on both of your questions.

Both FEKO and COMSOL are proprietary codes.  They are black boxes to users.  COMSOL does not even have proper theoretical manuals (unlike more theoretically grounded codes like ABAQUS and ADINA for example).
Does not give me a good feeling,do their users care about the theoretical basis for the code they are using? Why don't they have a theoretical manual?.  So no, you cannot get their source code or equations except on some vague terms on their Users Manuals (you can get much more detail on a book on Finite Element Analysis or the Boundary Element Method)..

On MathCad being able to do this well.  You need a code that can do Finite Element analysis, being able to effciently invert large matrices. Mathcad FE:   http://www.ptc.com/cad/simulation-software/fea

It does not even have an electromagnetic module.

not on the same level as FEKO and COMSOL

HFSS spits out all sorts of computed variables and even allows users to input their own equations using any computed variables. Couldnt power dissipated be computed using surface currents on all walls?
Are there any particular equations that I could try to numerically compute?

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