Author Topic: EM Drive Developments - related to space flight applications - Thread 3  (Read 1802090 times)

Offline flux_capacitor

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1. Copper at each end
2. Copper at the large end and silver at the small end
3. Silver at the small end and copper at the large end
4. Silver at each end
May I add:

5. Metglas at the large end

According to Fran De Acquino, Professor Emeritus of Physics, Maranhăo State University (UEMA) and Titular Researcher, National Institute for Space Research (INPE):

Fran De Aquino (2014). How the Thrust of Shawyer’s Thruster can be Strongly Increased <hal-01074608>
Metglas® 2714A is an amorphous metal alloy with a ultrahigh relative magnetic permeability µr = 1,000,000 which should strongly increase EmDrive thrust if plated on the large end. This was discussed previously in this thread.

Metglas® 2714A Magnetic Alloy spec sheet
« Last Edit: 07/26/2015 03:19 PM by flux_capacitor »

Offline deltaMass

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Those pix look a bit familiar. Ya Think???
« Last Edit: 07/26/2015 03:22 PM by deltaMass »

Offline deltaMass

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Suspect too many physicists and mathematicians have dug too deep a hole for themselves to ever admit they were mistaken about Shawyer.

When I get my rotary test rig up and spinning, will watch how many have the guts to admit they were wrong.
I sincerely hope you realise that statements like that cut both ways.
How about eating your hat? Up for that?
« Last Edit: 07/26/2015 03:31 PM by deltaMass »

Offline birchoff

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1. Copper at each end
2. Copper at the large end and silver at the small end
3. Silver at the small end and copper at the large end
4. Silver at each end
May I add:

5. Metglas at the large end

According to Fran De Acquino, Professor Emeritus of Physics, Maranhăo State University (UEMA) and Titular Researcher, National Institute for Space Research (INPE):

Fran De Aquino (2014). How the Thrust of Shawyer’s Thruster can be Strongly Increased <hal-01074608>
Metglas® 2714A is an amorphous metal alloy with a ultrahigh relative magnetic permeability µr = 1,000,000 which should strongly increase EmDrive thrust if plated on the large end. This was discussed previously in this thread.

Metglas® 2714A Magnetic Alloy spec sheet

Can this be included in a meep run?

Offline SeeShells

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I know this is not quite related to space flight or new propulsive ideas but it's something deeper and rests in the foundations of what and who we all are, it is the passion to learn and strive to learn and question and be better than we can ever believe we could be. It is as important as any formula posted.

I lost my mother last night and it's a very heavy hearted day. There is a plus side also, on reflecting on all of those who are here and even those who are just visiting. I know there was/is someone in your life who pushed you to learn and cheered you to take that next step. Whether it was your mother or father or someone you admired. It was my mother who instilled in me the faith that I could follow my dreams, solve the questions I had. She didn't even scold me when I took apart our only wind up alarm clock at 4, but instead helped me put it back together again.

She taught me that brilliance and the number of degrees you had or not was only one small part of the equation to discover truths, she taught me that passion and inquisitiveness and being encouraging and instilling that passion into others was the full equation to be successful.

I don't have the degrees some have here, I don't have the brilliance but I have the gift she gave me and that is the gift of passion and to encourage and cheer on a idea or thought and push to do it together. This is the other half of finding the truth. I thank her for that.

I will continue to cheer others on and be kind and thoughtful and look at their thought and ideas as they were the most important thing in the world, for those equations and formulas are derived from knowledge but are driven by passion.

I'm sorry this isn't about a scientific thought or a new wizzbang formula but in truth it is the other side of what makes this work and that's the passion of the Woo Hoo moment we're all after.

Shell

Offline RotoSequence

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Sorry for the awful news, Shells :(



Is there a reasonable expectation of ARXIV getting a copy of M. Tajmar's paper on Tuesday?
« Last Edit: 07/26/2015 03:39 PM by RotoSequence »

Offline deltaMass

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Shells - my heartfelt condolences on your loss.

Offline TheTraveller

1. Copper at each end
2. Copper at the large end and silver at the small end
3. Silver at the small end and copper at the large end
4. Silver at each end
May I add:

5. Metglas at the large end

According to Fran De Acquino, Professor Emeritus of Physics, Maranhăo State University (UEMA) and Titular Researcher, National Institute for Space Research (INPE):

Fran De Aquino (2014). How the Thrust of Shawyer’s Thruster can be Strongly Increased <hal-01074608>
Metglas® 2714A is an amorphous metal alloy with a ultrahigh relative magnetic permeability µr = 1,000,000 which should strongly increase EmDrive thrust if plated on the large end. This was discussed previously in this thread.

Metglas® 2714A Magnetic Alloy spec sheet

Thanks for that.

2 issues.

1) In a EMDrive the EM wave bounces off the end plate and gets 2x the inward momentum lick on the end plate (1x from the photons being absorbed and 1x from the photons being re emitted) and get to do that as many times as the Q allows. Of course the re emitted photons have a red shifted wavelength as some of their energy is now in the end plate, that is assuming the end plate can be moved / accelerated.

2) In the attached Permeability versus Frequency curves the 100kHz permeability value has really dropped. Don't believe there would be anything there at 2.45GHz as the magnetic domains just can't move / rotate into alignment or not that quickly. Having a saturation of 0.57T s very impressive, especially as most material like this saturate at very low T values and then any mag fields above saturation go through the material like a hot knife through butter.
"As for me, I am tormented with an everlasting itch for things remote. I love to sail forbidden seas.”
Herman Melville, Moby Dick

Offline demofsky

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....
She taught me that brilliance and the number of degrees you had or not was only one small part of the equation to discover truths, she taught me that passion and inquisitiveness and being encouraging and instilling that passion into others was the full equation to be successful.

I don't have the degrees some have here, I don't have the brilliance but I have the gift she gave me and that is the gift of passion and to encourage and cheer on a idea or thought and push to do it together. This is the other half of finding the truth. I thank her for that.
....

So very sorry for your loss.  And thank you very much for sharing these thoughts.  This is what drives us all here each in our own way.

Online aero

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Interesting that Tajmar's EMDrive had the ability to vary the cavity length, to get resonance. As did the Shawyer Experimental and Demonstrator EMDrives.

This post shows an image ot Tajmar's cavity and wave guide. I have modelled the bare cavity in meep, in perfect metal and driven by an antenna. I could not detect resonance at 2.44 GHz but an image of the cavity field patterns (or lack of patterns) is attached. The antenna was to long for the cavity, but the correct length for the frequency.

I did detect huge (meep's trick with Q) resonance above 4 GHz, and have attached an image.

I also generated images at 4.376 GHz with lateral antenna configured 1/4 wavelength from the small end and at 4.717 GHz with axial antenna 1/4 wavelength from the small end. In both cases the antenna length was correct based on the frequency. However the small size of the cavity resulted in 1/4 wavelength from the small end being less than 1/4 wavelength from the big end. The cavity is less than 1/2 wavelength long?

It seems that the next logical step would be to model the wave guide and the cavity together as any resonance at 2.44 GHz must include the field energies within the big wave guide and the cavity. That might also explain the unexpected lateral force measured.
Retired, working interesting problems

Offline TheTraveller

I know this is not quite related to space flight or new propulsive ideas but it's something deeper and rests in the foundations of what and who we all are, it is the passion to learn and strive to learn and question and be better than we can ever believe we could be. It is as important as any formula posted.

I lost my mother last night and it's a very heavy hearted day. There is a plus side also, on reflecting on all of those who are here and even those who are just visiting. I know there was/is someone in your life who pushed you to learn and cheered you to take that next step. Whether it was your mother or father or someone you admired. It was my mother who instilled in me the faith that I could follow my dreams, solve the questions I had. She didn't even scold me when I took apart our only wind up alarm clock at 4, but instead helped me put it back together again.

She taught me that brilliance and the number of degrees you had or not was only one small part of the equation to discover truths, she taught me that passion and inquisitiveness and being encouraging and instilling that passion into others was the full equation to be successful.

I don't have the degrees some have here, I don't have the brilliance but I have the gift she gave me and that is the gift of passion and to encourage and cheer on a idea or thought and push to do it together. This is the other half of finding the truth. I thank her for that.

I will continue to cheer others on and be kind and thoughtful and look at their thought and ideas as they were the most important thing in the world, for those equations and formulas are derived from knowledge but are driven by passion.

I'm sorry this isn't about a scientific thought or a new wizzbang formula but in truth it is the other side of what makes this work and that's the passion of the Woo Hoo moment we're all after.

Shell

I'm so sorry to learn your sad news.

When I lost my dad, I told my mother (who has also since passed) that dad will live on in our memories and to think of him many times every day.

Every day I think of them both and how they protected me from my grandmother when I (at eight) took apart a 150 years old French mantle clock that had not worked for a long time. Lucky for me I found the fault, put the clock back together and as far as I know it still works.

They say good engineers are born. I guess we just proved that.

Keep your mothers memory alive and she will live on in you.
« Last Edit: 07/26/2015 03:53 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 SeeShells

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Interesting that Tajmar's EMDrive had the ability to vary the cavity length, to get resonance. As did the Shawyer Experimental and Demonstrator EMDrives.

This post shows an image ot Tajmar's cavity and wave guide. I have modelled the bare cavity in meep, in perfect metal and driven by an antenna. I could not detect resonance at 2.44 GHz but an image of the cavity field patterns (or lack of patterns) is attached. The antenna was to long for the cavity, but the correct length for the frequency.

I did detect huge (meep's trick with Q) resonance above 4 GHz, and have attached an image.

I also generated images at 4.376 GHz with lateral antenna configured 1/4 wavelength from the small end and at 4.717 GHz with axial antenna 1/4 wavelength from the small end. In both cases the antenna length was correct based on the frequency. However the small size of the cavity resulted in 1/4 wavelength from the small end being less than 1/4 wavelength from the big end. The cavity is less than 1/2 wavelength long?

It seems that the next logical step would be to model the wave guide and the cavity together as any resonance at 2.44 GHz must include the field energies within the big wave guide and the cavity. That might also explain the unexpected lateral force measured.
You're quick.

Could you do a 1/4 wave snub in the sidewall, enough room?

Online Rodal

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Interesting that Tajmar's EMDrive had the ability to vary the cavity length, to get resonance. As did the Shawyer Experimental and Demonstrator EMDrives.

This post shows an image ot Tajmar's cavity and wave guide. I have modelled the bare cavity in meep, in perfect metal and driven by an antenna. I could not detect resonance at 2.44 GHz but an image of the cavity field patterns (or lack of patterns) is attached. The antenna was to long for the cavity, but the correct length for the frequency.

I did detect huge (meep's trick with Q) resonance above 4 GHz, and have attached an image.

I also generated images at 4.376 GHz with lateral antenna configured 1/4 wavelength from the small end and at 4.717 GHz with axial antenna 1/4 wavelength from the small end. In both cases the antenna length was correct based on the frequency. However the small size of the cavity resulted in 1/4 wavelength from the small end being less than 1/4 wavelength from the big end. The cavity is less than 1/2 wavelength long?

It seems that the next logical step would be to model the wave guide and the cavity together as any resonance at 2.44 GHz must include the field energies within the big wave guide and the cavity. That might also explain the unexpected lateral force measured.



Thank you for doing this work.

Excellent point about the "unexpected lateral force measurement".   I completely agree, it must be due to the huge opening from the waveguide.

I enclose strictly for discussion, research and illustration purposes Fig. 2, page 3 of Tajmar et.al. about the COMSOL Finite Element Analysis of the waveguide, to help in modeling it with Meep.
Notice how huge is the entrance of the waveguide into TU Dresden's EM Drive cavity:


 “…for purposes such as criticism, comment, news reporting, scholarship, or research…” under US Fair Use

http://fairuse.stanford.edu/overview/fair-use/what-is-fair-use/

This is the  American Institute of Aeronautics and Astronautics link to Martin Tajmar's et.al. paper, that should be obtained from the American Institute of Aeronautics and Astronautics:

Direct Thrust Measurements of an EM Drive and Evaluation of Possible Side-Effects  M. Tajmar and G. Fiedler
51st AIAA/SAE/ASEE Joint Propulsion Conference


http://arc.aiaa.org/doi/pdf/10.2514/6.2015-4083

Notice the huge waveguide opening to the right and how the electromagnetic field is distorted into the waveguide opening, clearly showing how the waveguide affects the field

« Last Edit: 07/26/2015 05:33 PM by Rodal »

Offline TheTraveller

Suspect too many physicists and mathematicians have dug too deep a hole for themselves to ever admit they were mistaken about Shawyer.

When I get my rotary test rig up and spinning, will watch how many have the guts to admit they were wrong.
I sincerely hope you realise that statements like that cut both ways.
How about eating your hat? Up for that?

Absolutely. When I post the experimental data it will either be victory or a bitter pill to swallow.

I have no doubt about getting Force generation from my 100W of Rf. Only unknown is how much Force will be generated. Even there I have no doubt I can get a really excellent Force value as I have heaps of tuning tools at my disposal to "Train My Dragon".

Prof Yang has shown there is an art and method to developing a 117,500 Q cavity.

I'm now considering making both end of my design with a sliding end plate, to duplicate the 49 step process Prof Yang's team developed to "Train Their Dragon". At least initially, then can maybe design in the optimal step out distance at each end. This short length, constant diameter, cylindrical step out ("retraction" size of the cover depth) design also seems to eliminate the need for spherical end plates, which would be a really big win.

Quote
With 7 sets of different retraction size of the cover depth, you can get 49 kinds of different combinations for large small end retraction different depths,

debugging within selected large end retraction depth 4 mm, 12 mm small end retraction depth is the best combination, at this point closest to the resonant frequency of 2.45 GHz
« Last Edit: 07/26/2015 06:05 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 Star One

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I know this is not quite related to space flight or new propulsive ideas but it's something deeper and rests in the foundations of what and who we all are, it is the passion to learn and strive to learn and question and be better than we can ever believe we could be. It is as important as any formula posted.

I lost my mother last night and it's a very heavy hearted day. There is a plus side also, on reflecting on all of those who are here and even those who are just visiting. I know there was/is someone in your life who pushed you to learn and cheered you to take that next step. Whether it was your mother or father or someone you admired. It was my mother who instilled in me the faith that I could follow my dreams, solve the questions I had. She didn't even scold me when I took apart our only wind up alarm clock at 4, but instead helped me put it back together again.

She taught me that brilliance and the number of degrees you had or not was only one small part of the equation to discover truths, she taught me that passion and inquisitiveness and being encouraging and instilling that passion into others was the full equation to be successful.

I don't have the degrees some have here, I don't have the brilliance but I have the gift she gave me and that is the gift of passion and to encourage and cheer on a idea or thought and push to do it together. This is the other half of finding the truth. I thank her for that.

I will continue to cheer others on and be kind and thoughtful and look at their thought and ideas as they were the most important thing in the world, for those equations and formulas are derived from knowledge but are driven by passion.

I'm sorry this isn't about a scientific thought or a new wizzbang formula but in truth it is the other side of what makes this work and that's the passion of the Woo Hoo moment we're all after.

Shell

Sorry to hear your sad news you have my condolences.

Offline deltaMass

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Some experimenters would be pretty content with about 100 uN but Tajmar gets about that in the direction at right angles to the frustum axis (labelled "Horizontal" on his graph). Having read through the foregoing posts, it seems likely that the huge waveguide orifice has something to do with this. He's basically extended the cavity geometry a little way at right angles to the frustum main axis.

Offline Star One

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Will the Tajmar talk be viewable afterwards say on You Tube etc?

Online aero

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@SeeShell,
You have my deepest condolences for your loss.

And regarding a 1/4 wavelength stub antenna in the sidewall (midpoint?), I can do that but likely not today as it is my boy's 5 birthday party at the park with all his school friends and parents so as co-host, I will be there.

aero
Retired, working interesting problems

Offline rfmwguy

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doing frustum research in frankenmuth michigan today  :)

Online Rodal

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Some experimenters would be pretty content with about 100 uN but Tajmar gets about that in the direction at right angles to the frustum axis (labelled "Horizontal" on his graph). Having read through the foregoing posts, it seems likely that the huge waveguide orifice has something to do with this. He's basically extended the cavity geometry a little way at right angles to the frustum main axis.

Excellent observation, deltaMass.  In retrospect this is almost obvious, but it is not pointed out in the paper as a possible explanation for the side force.

This is another possible question to discuss with Tajmar at the AIAA presentation.

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