Author Topic: EM Drive Developments - related to space flight applications - Thread 5  (Read 764084 times)

Offline A_M_Swallow

  • Elite Veteran
  • Senior Member
  • *****
  • Posts: 8174
  • South coast of England
  • Liked: 255
  • Likes Given: 106
{snip}
As for why bother to include the no-resonance?  Well, there are a lot of folks here who believe it's a meaningful thing to have, so I'd include those tests just to be politically correct.
{snip}

One of the things we have to demonstrate experimentally is that the EM Drive effect is dependant on frequency, we have been assuming it.
« Last Edit: 10/27/2015 07:52 PM by A_M_Swallow »

Offline wallofwolfstreet

  • Full Member
  • *
  • Posts: 165
  • Liked: 169
  • Likes Given: 436
Now you done tossed something onto the table that I hadn't thought of.

I would assume that your Y is zero without resonance, but it may not be, so I have to add in a non-resonant value for Y.


Good point, a non-resonant value for Y should definitely be included.


Quote
In any event, it looks to me like it is possible to see a signal as small as 1/10th the thermal, in spite of all the above, provided the noise can be kept low.

When you say "see" a signal, do you mean you calculate a number for Y from repeated measurements of (resonance, up), (resonance,down), ..., (no resonance, down)?  If so, how?  You have 4 equations and 6 unknowns (with non-resonant value of Y).  I don't see how you could uniquely determine what the value of either Y is. 

Offline glennfish

  • Full Member
  • ***
  • Posts: 387
  • Liked: 281
  • Likes Given: 168
Now you done tossed something onto the table that I hadn't thought of.

I would assume that your Y is zero without resonance, but it may not be, so I have to add in a non-resonant value for Y.


Good point, a non-resonant value for Y should definitely be included.


Quote
In any event, it looks to me like it is possible to see a signal as small as 1/10th the thermal, in spite of all the above, provided the noise can be kept low.

When you say "see" a signal, do you mean you calculate a number for Y from repeated measurements of (resonance, up), (resonance,down), ..., (no resonance, down)?  If so, how?  You have 4 equations and 6 unknowns (with non-resonant value of Y).  I don't see how you could uniquely determine what the value of either Y is.

Captain, I'm more of a statistician than a metrologist.   I would be happy if one could conclude Y is non zero.

As to what the value of Y is?  If the signals were anything like the model, you could estimate it, if the data were as clean as I simulate it.

Reality will impose it's ugly truth and things will drift from oxidation, inconsistent timings, aging capacitors, sticky scales, experimentor dropping something, all the plagues of engineering implementations.  All those nasties that drift into post-hoc = unacceptable analysis.

I think at this stage, it's perhaps enough to say, "If Y > 10% of the thermal value, and the noise level is around 10%, then if there is a non-zero Y, it might be obvious in the data, provided the other unknowns are not too large to override the signal"

As for actually solving for Y?  Let's see, we have 7 variables, and no knowns.   I don't recall any mathematical way to solve that one.  Maybe after 3 or 4 scotch on the rocks I could solve it, but you'd have to have 5 or 6 to agree.

I think the best we can do is say, in a DIY framework, you picks your assumptions and run with them.  If you're lucky, the data says you weren't wasting your time.  The simulation says, it's possible  (<> likely) that a careful experimenter could get an interesting result absent a vacuum chamber or hermetically sealed chamber.

The up side is, there are enough folks reading this that one of them will look at your analysis and say, "I have a 3D printer.  I can build a hermetically sealed chamber!"  Until then, the community has to work with the DIY folks who've revealed themselves.

My simple goal is to demonstrate that with what's on the table today, it's possible to create an interesting result.

The simulation says that if you pick "plausible" values for these 7 variables, a signal could be visible.  It does not say that I picked "plausible" values. 

Offline glennfish

  • Full Member
  • ***
  • Posts: 387
  • Liked: 281
  • Likes Given: 168

When you say "see" a signal, do you mean you calculate a number for Y from repeated measurements of (resonance, up), (resonance,down), ..., (no resonance, down)?  If so, how?  You have 4 equations and 6 unknowns (with non-resonant value of Y).  I don't see how you could uniquely determine what the value of either Y is.

The UP thermal and the DOWN thermal should be the (Up thermal + up asymmetry) and the (Down thermal + down asymmetry).  Even though there are 4 variables there, the physical manifestation should be the sum, hence two variables?

Yes?  No?

Offline zen-in

  • Full Member
  • ****
  • Posts: 531
  • California
  • Liked: 468
  • Likes Given: 365

...

IMHO controling for oxidation is good, and I'm sure when you look in any 19th century mirror, you know that your coating will oxidize.   :)  But you're right, silver oxide should behave better than copper oxide, although it's not as pretty after a century or two.

One other stupid thought, is there any way at all to measure the Q value at the beginning and end of each run, or during the run?  That data in itself could be quite useful, especially if the hypothesis relates Q to lift.

Silver does not oxidize easily.   Silver tarnish happens because silver undergoes a chemical reaction with sulfur-containing substances in the air.    It doesn't affect the surface conductivity at DC; which is why some swiches have Silver contacts.   As long as there is no Sulfur around, especially H2S, the Silver will not tarnish.   if it is Fine Silver (99.99% pure) it can be heated to its melting point and will be white when it has cooled down.   The problem with Silver plating is getting good adhesion.   I have done some Silver plating, using Silver Cyanide solutions.    When first applied the Silver plating is soft and easily smeared off.   After rinsing and allowing it to dry for a few hours the Silver plating hardens and adheres.   I have never used the plating brushes.  I suspect the quality is not as good and that plating over it with Gold would not produce a good result.   It also may not be Fine Silver that is being plated so the electrical benefit may not be there.
« Last Edit: 10/27/2015 10:21 PM by zen-in »

Offline wallofwolfstreet

  • Full Member
  • *
  • Posts: 165
  • Liked: 169
  • Likes Given: 436
Captain, I'm more of a statistician than a metrologist.   I would be happy if one could conclude Y is non zero.

As to what the value of Y is?  If the signals were anything like the model, you could estimate it, if the data were as clean as I simulate it.

...

I think at this stage, it's perhaps enough to say, "If Y > 10% of the thermal value, and the noise level is around 10%, then if there is a non-zero Y, it might be obvious in the data, provided the other unknowns are not too large to override the signal"

As for actually solving for Y?  Let's see, we have 7 variables, and no knowns.   I don't recall any mathematical way to solve that one.  Maybe after 3 or 4 scotch on the rocks I could solve it, but you'd have to have 5 or 6 to agree.

I think the best we can do is say, in a DIY framework, you picks your assumptions and run with them.  If you're lucky, the data says you weren't wasting your time.  The simulation says, it's possible  (<> likely) that a careful experimenter could get an interesting result absent a vacuum chamber or hermetically sealed chamber.

The up side is, there are enough folks reading this that one of them will look at your analysis and say, "I have a 3D printer.  I can build a hermetically sealed chamber!"  Until then, the community has to work with the DIY folks who've revealed themselves.

My simple goal is to demonstrate that with what's on the table today, it's possible to create an interesting result.

The simulation says that if you pick "plausible" values for these 7 variables, a signal could be visible.  It does not say that I picked "plausible" values.

I was actually being a bit rhetorical when I asked about solving for Y when you have 5 unknowns and only the 4 equations, because it's not doable.  No method in math, or statistics, or anything else that makes it possible.  The corollary of that is also that it is impossible to even determine if Y is non-zero.  To know anything about Y, you have to do the math and analysis on some of the other variables I gave in this post, but then we're back to my original complaint about mathematically characterizing thermal lift:

Quote
Yes, the equations are basic undergraduate electronics and some slightly more complicated heat transfer.  Getting accurate quantities for the variables isn't easy however, and validating the accuracy would require experimental runs regardless, so this procedure doesn't really save any work. 


The UP thermal and the DOWN thermal should be the (Up thermal + up asymmetry) and the (Down thermal + down asymmetry).  Even though there are 4 variables there, the physical manifestation should be the sum, hence two variables?

Yes?  No?

Right, there are two variables, UP thermal and DOWN thermal.  But in your model with choosing resonance, there is UP, RESONANCE thermal and DOWN, RESONANCE therma etc.  Still 4 unknowns for every combination of orientations and resonance, plus the fifth unknown for device thrust. 

Offline TheTraveller

Shell,

I'm back home and recovering nicely from the extended robot entry wound site infection. SHould restart the rad treatment soon.

Did your requested resonance data.

As you can see achieving TE012 resonance will probably not happen as you will need to inject Rf around 2.3gHz. However from the resonance mode map I did, there should be a lot of lengths that will give you resonance at the freq output range of the maggie

Based on 90% of your 750Ws getting into the frustum and using a conservative unloaded Q of 10,000, the Force generation potential is, assuming you can get a narrow band of Rf from the maggie that fits inside the frustum's 250kHz bandwidth, around 30mNs.
"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

A comment on the thermal lift.

If the Rf is not inside the frustum bandwidth, most of it will be reflected back toward the Rf generator. If there is a circulator and reflected Rf load in pace the reflected energy will thermalise there. If not it will heat up the magnetron.

Which means there can be 3 sources for heat to be radiated.

1) if operating at resonance, outer surface radiation from the frustum side walls and end plates.

2) the magnetron heat radiators.

3) if used, the reflected Rf heat radiator.

I would note that Roger appears to have used a circulator and external reflected heat radiator with all the EMDrives. Can be seen here in his schematic of the Experimental EMDrive.

Using a circulator and reflected heat radiator ensures the experimenter will know where any reflected / non resonance energy will turn into heat and can design to handle it.
« Last Edit: 10/27/2015 11:33 PM by TheTraveller »
"As for me, I am tormented with an everlasting itch for things remote. I love to sail forbidden seas.
Herman Melville, Moby Dick

Offline ThinkerX

  • Full Member
  • ***
  • Posts: 311
  • Alaska
  • Liked: 120
  • Likes Given: 59
Given the thermal lift issues, some form of horizontal (rotary) test may be preferable.

The thermal lift would affect vertical movement, not horizontal.

Would multiple DIY repeats of Shawyers rotary test be of value in determining if the EN Drive is 'real?'

Offline glennfish

  • Full Member
  • ***
  • Posts: 387
  • Liked: 281
  • Likes Given: 168

I was actually being a bit rhetorical when I asked about solving for Y when you have 5 unknowns and only the 4 equations, because it's not doable.  No method in math, or statistics, or anything else that makes it possible.  The corollary of that is also that it is impossible to even determine if Y is non-zero.  To know anything about Y, you have to do the math and analysis on some of the other variables I gave in this post, but then we're back to my original complaint about mathematically characterizing thermal lift:


Thinking.  Gut feel is I don't agree, but I need to "sleep" on this to figure out why.  :)

Gut says, finding a difference statistically is necessary and sufficient.

Your argument is it's not sufficient.

I think I agree that it's not sufficent, but I think finding what I propose is the 1st half, necessary.

More tomorrow.  I do better dreaming problems.  :)

Offline rfmwguy

  • EmDrive Builder (retired)
  • Senior Member
  • *****
  • Posts: 2165
  • Liked: 2681
  • Likes Given: 1124
Attached is a paper just released by reddit user potomac_neuron who suggests emdrive effects are lorentz force induced. A video of the torsion balance test stand is included.


Offline glennfish

  • Full Member
  • ***
  • Posts: 387
  • Liked: 281
  • Likes Given: 168
Attached is a paper just released by reddit user potomac_neuron who suggests emdrive effects are lorentz force induced. A video of the torsion balance test stand is included.



Nope.  John Baez has some incredibly powerful critiques.   This barely makes the chinese fortune cookie level.

There are many very good reasons to claim EM drives can't work.   

There are probably MORE good reasons to claim this group should never be admitted to high school.

On the otherhand, they could be commended for taking a swat at this.

IMHO.  And I'm being nice.   Sorry.

Can't wait to see CK's comments on Reddit.  He was all over this paper chomping for a chance to read it.  I see dry heaves in his future.
« Last Edit: 10/28/2015 02:19 AM by glennfish »

Offline SeeShells

  • Senior Member
  • *****
  • Posts: 2335
  • Every action there's a reaction we try to grasp.
  • United States
  • Liked: 2982
  • Likes Given: 2601
Attached is a paper just released by reddit user potomac_neuron who suggests emdrive effects are lorentz force induced. A video of the torsion balance test stand is included.



Nope.  John Baez has some incredibly powerful critiques.   This barely makes the chinese fortune cookie level.

There are many very good reasons to claim EM drives can't work.   

There are probably MORE good reasons to claim this group should never be admitted to high school.

On the otherhand, they could be commended for taking a swat at this.

IMHO.  And I'm being nice.   Sorry.

Can't wait to see CK's comments on Reddit.  He was all over this paper chomping for a chance to read it.  I see dry heaves in his future.
Nice compass? Sorry I'm sure he tried, no bad data.
« Last Edit: 10/28/2015 02:27 AM by SeeShells »

Offline SeeShells

  • Senior Member
  • *****
  • Posts: 2335
  • Every action there's a reaction we try to grasp.
  • United States
  • Liked: 2982
  • Likes Given: 2601
Spent most of the day waiting for my truck. Lost another one. So tomorrow no interruptions! Work need to get done.


Offline demofsky

  • Full Member
  • *
  • Posts: 165
  • Liked: 96
  • Likes Given: 1668
" http://forum.nasaspaceflight.com/index.php?topic=38577.msg1439633#msg1439633
This whole approach requires some thought but one way or another I really think areo has a breakthrough idea here!  :D "

Yep he does, aero is one sharp man. It's called a controlled micro environment. Add a a flex cooling line and a fan... bingo!

The cooling hose only connects to the fulcrum beam and the fan isn't attached to the beam but sits on the base of the testing stand. Done correctly this would have little or no impact on the movement of the beam and remove most of the thermal balloon effects.
http://masterduct.com.tempdomain.com/SearchProducts/SearchResults/tabid/116/CategoryID/22/List/1/Level/a/ProductID/73/language/en-US/Default.aspx
I think it is something that just might work... what do you think?

Shell

Added: Sorry this is such a crude drawing and I'm sure there are mods that need to be considered, air insertion points and attachments to the beam and materials. I was simply excited.

One more thing... http://www.homedepot.com/p/Tripp-Lite-Portable-Cooling-Unit-or-Air-Conditioner-3-4-kW-120-Volt-60-Hz-12K-BTU-SRCOOL12K/203796126

Oops another: http://www.homedepot.com/p/Speedi-Products-3-in-x-20-ft-Standard-White-Vinyl-Flexible-Hose-EX-SVH-03/202907361

I really like this.  I think areo's suggestionto use the fan to draw away hot air is also very good.  If you use that approach do you need an input hose or can you use some sort of diffuser attached to the insulated chamber (bag)???

That said, rmfwguy and glennfish have a very valid point about simplicity.  This suggests a staged approach with the simplest configuration first followed by more advanced thermal controls. 

Whichever approach taken, we now have options for thermal controls and that is great!

Offline SeeShells

  • Senior Member
  • *****
  • Posts: 2335
  • Every action there's a reaction we try to grasp.
  • United States
  • Liked: 2982
  • Likes Given: 2601
" http://forum.nasaspaceflight.com/index.php?topic=38577.msg1439633#msg1439633
This whole approach requires some thought but one way or another I really think areo has a breakthrough idea here!  :D "

Yep he does, aero is one sharp man. It's called a controlled micro environment. Add a a flex cooling line and a fan... bingo!


I really like this.  I think areo's suggestionto use the fan to draw away hot air is also very good.  If you use that approach do you need an input hose or can you use some sort of diffuser attached to the insulated chamber (bag)???

That said, rmfwguy and glennfish have a very valid point about simplicity.  This suggests a staged approach with the simplest configuration first followed by more advanced thermal controls. 

Whichever approach taken, we now have options for thermal controls and that is great!

Simple first, a big KISS to start it off with.

Shell

Keep It Simple Stupid.... of course. :)
« Last Edit: 10/28/2015 03:20 AM by SeeShells »

Offline ChrisWilson68

  • Senior Member
  • *****
  • Posts: 3520
  • Sunnyvale, CA
  • Liked: 2083
  • Likes Given: 2468
Attached is a paper just released by reddit user potomac_neuron who suggests emdrive effects are lorentz force induced. A video of the torsion balance test stand is included.



Nope.  John Baez has some incredibly powerful critiques.   This barely makes the chinese fortune cookie level.

There are many very good reasons to claim EM drives can't work.   

There are probably MORE good reasons to claim this group should never be admitted to high school.

On the otherhand, they could be commended for taking a swat at this.

IMHO.  And I'm being nice.   Sorry.

Can't wait to see CK's comments on Reddit.  He was all over this paper chomping for a chance to read it.  I see dry heaves in his future.

Doesn't anyone here have any reply at all to the substance of this paper?  Just throwing out insults without providing any justification for the insults isn't very persuasive.


Offline Bob Woods

  • Full Member
  • **
  • Posts: 239
  • Salem, Oregon USA
  • Liked: 329
  • Likes Given: 1051
"Part of the healing process is sharing with other people who care."  - Jerry Cantrell

TT, your sharing is a gift. Not just to Shell, but to all who believe in knowledge.

I hope your knowledge and gentle prodding helps others grow and succeed in their tasks.

And I hope your sharing helps you heal.

Offline SeeShells

  • Senior Member
  • *****
  • Posts: 2335
  • Every action there's a reaction we try to grasp.
  • United States
  • Liked: 2982
  • Likes Given: 2601
Attached is a paper just released by reddit user potomac_neuron who suggests emdrive effects are lorentz force induced. A video of the torsion balance test stand is included.



Nope.  John Baez has some incredibly powerful critiques.   This barely makes the chinese fortune cookie level.

There are many very good reasons to claim EM drives can't work.   

There are probably MORE good reasons to claim this group should never be admitted to high school.

On the otherhand, they could be commended for taking a swat at this.

IMHO.  And I'm being nice.   Sorry.

Can't wait to see CK's comments on Reddit.  He was all over this paper chomping for a chance to read it.  I see dry heaves in his future.

Doesn't anyone here have any reply at all to the substance of this paper?  Just throwing out insults without providing any justification for the insults isn't very persuasive.
One thing strikes me in this test and even reading the paper. And this is as a builder first.

I would have liked to see them use Mumetal, Nikel Permalloy, Magnetic shielding foil to shield the DUT from magnetic forces. It would have been a good investment.


Offline meberbs

  • Full Member
  • ****
  • Posts: 1331
  • Liked: 1229
  • Likes Given: 313
Doesn't anyone here have any reply at all to the substance of this paper?  Just throwing out insults without providing any justification for the insults isn't very persuasive.

As far as I can tell, the experiment is just measuring the Lorentz force on a device with a current running through it due to the Earth's magnetic field. They point out in the Appendix that due to different grounding points in the null and resonating cavity tests, the Lorentz force may not have been correctly accounted for in the Eagleworks experiment. This just adds one more possible explanation of experimental error that could be the real cause for the small thrust measured by Eagleworks.

This is a paper explaining why the emdrive thrust is just an error in the experiment design. It could use a bit more rigor in parts, but its point is to demonstrate that a significant source of error exists, not to precisely measure the magnitude, which would require them to have access to the original experiment equipment.

To reiterate, this paper claims (reasonably) that the measured thrust is an experimental error, and suggests an incorrect calibration of the Lorentz force effect on the setup as the cause of the error.

Tags: