Author Topic: EM Drive Developments - related to space flight applications - Thread 3  (Read 1805414 times)

Offline rfmwguy

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I can't recall anyone doing any deliberate modulation/pulsing of the power input so I want to highlight this for everyone's consideration.

(I am catching up on this thread so apologies for the late question for this post.)
Paul March from NASA discussed frequency, amplitude and phase modulation produced by the Magnetron in NSF EM Drive Thread 2.   He showed the results of Dr. White's computer analysis (based on his QV theory) to the effect that the modulation provided by the Magnetron should result in much greater thrust as per White's theory.  Therefore they designed a series of tests to be run with Magnetron providing modulation, that are scheduled to be run this Summer.

Thought experiment continues (in my mind only :P)

I watched White's Ames presentation again, this time paying much closer attention. Seems he is hanging his hat exclusively on QV to avoid the CoM fight. His submarine analogy makes sense IF he can demonstrate how the EM fields interacts with it. This is the gap I have struggled with as my own general theories shift about. It seems it would have to be more than simple standing wave interactions as that implies static displacement (suspended items in acoustic wave tests). I can only visualize the drive working in a corkscrew fashion, twisting into the QV, i.e. pulling itself. The leap of faith here is the physics of the QV. EM I can visualize fairly well, QV is largely over my head and the EM-QV coupling is way beyond me. However, am curious enough to keep plugging away. Perhaps the mode modeling, which I have enjoyed viewing, can be converted into moving fields or resonances...seems this has to be the mechanism IF the drive is to become a reality. /end ramble.

Offline rfmwguy

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...Sorry, thrust estimate in the 185 mg range I believe is what the spreadsheet said...snarky comment accepted ;)
What formula are you using to estimate the thrust force as 185 mg and what were the input parameters you used for the formula?
I'll have to go back and look at home, believe its travellers spreadsheet.

edit...here it is:

N thrust calculator derived from T = 2DfPoQ/c            
Q   50,000   Cavity Q   1.884   mN thrust
Po   8   Watts input   1.884   mN thrust
Df   0.7059   Design Factor   0.19   gf
« Last Edit: 06/22/2015 03:14 PM by rfmwguy »

Offline Rodal

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I'll have to go back and look at home, believe its travellers spreadsheet.

edit...here it is:

N thrust calculator derived from T = 2DfPoQ/c            
Q   50,000   Cavity Q   1.884   mN thrust
Po   8   Watts input   1.884   mN thrust
Df   0.7059   Design Factor   0.19   gf

A lot depends on the Q and the validity of the formula, of course. If Q=5,000, the force is 1/10 of the calculated value.  If Q=1,000 then it is 1/50 of the calculated value.   
« Last Edit: 06/22/2015 03:20 PM by Rodal »

Offline SeeShells

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Time to start my build.

I think I have most of the info to be sure I can get something viable from a first test. Thanks to all of you! You're all Supermen (women too) in my mind!

I'm basing the cavity on Yang's sizes @2.45 Ghz, keeping the Frustum angle shallow like theirs but extending it to only 1 inch in diameter at the small end. I'm allowing the Cavity to be able to be flexible so as to remove and replace the small endplates to test different harmonics and modes while only changing the small endplate. I think Dr. Rodal's ideas mirror my thoughts here (Loved the write up BTW Jose) and the smaller endplates will lead to greater forces being exhibited. The fine tuning is going to be done through a lead screw in the large endplate, which is concave. Note: I've a English wheel and have put a very nice curve into a piece of soft sheet metal just to test if it could be done.

The material is going to be ~ 18 Gauge Perforated Copper sheet. I found some at a surplus metal company but it's a 150 mile RT drive to get it and he said he has others I need to look at also. Just got a 32" sheet metal break to make my bends.

I'm going to use a Microwave Magnetron rated at 800w and 2.45 Ghz as it's cheap and should give me a DC component as well as a broad frequency spread enough to get any forces above the noise level. Important! ... a fine mesh Chicken wire cage to enclose the entire thing as we need WiFi and to keep the FCC happy. ;)

I like being able to get into the cavity to change the Microwave antenna and the endplates plus being able see inside the maelstrom of microwave cavity activity might prove to be a plus.

I have some thoughts on the testing rig and still working those out. I like the fulcrum with the oil damping idea and I'll post a drawing of my thoughts later, but I want to get the Frustum built first.

Shell

Offline rfmwguy

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I'll have to go back and look at home, believe its travellers spreadsheet.

edit...here it is:

N thrust calculator derived from T = 2DfPoQ/c            
Q   50,000   Cavity Q   1.884   mN thrust
Po   8   Watts input   1.884   mN thrust
Df   0.7059   Design Factor   0.19   gf

A lot depends on the Q and the validity of the formula, of course. If Q=5,000, the force is 1/10 of the calculated value.  If Q=1,000 then it is 1/50 of the calculated value.

Very true. 50K is a tall order. I've always calculated Q as Ctr Freq/3dB Bandwidth in the filter world. Q determination in a closed cavity is another story. The sample ports on previous frustums would provide the necessary BW performance. I cannot imagine the frustum is a narrow band device. S11 and S21 charts would be nice to see. Probably need to refresh myself on other Q determinates. Skin depth @ 2.45 GHz is sub-micron, so eddy losses are low, especially on a copper screen mesh, so in my world, thats a major factor in frustum construction; EM containment with minimal eddy current losses. I could be way off on this way of thinking...prelim test results will let me know...

Offline Rodal

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I like being able to get into the cavity to change the Microwave antenna and the endplates plus being able see inside the maelstrom of microwave cavity activity might prove to be a plus.

..

This is looking like it is going to be the best designed EM Drive test ever performed !

I will not be surprised if you see plasma inside the EM Drive, I look forward to seeing the experiment !

The RF feed location looks very important, based on aero's MEEP analysis.

Am I reading you correctly that you will have the ability to change the RF feed location at will by being able to get into the cavity? 

Offline aero

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@ Dr. Rodal -

Attached are images of the Brady cavity and the Rodal cavity showing antenna location. Are you sure you want to place the antenna where EW had theirs placed? Before you answer that, take a look at the field patterns here:

Brady_corner_ant
https://drive.google.com/folderview?id=0B1XizxEfB23tfjBKSFF2dFp4WVV2MEZzNUtOU3NmdTZrQWd0dVo4WFIxcll0NDZEUjFXeEk&usp=sharing

and here:
Rodal_corner_ant
https://drive.google.com/folderview?id=0B1XizxEfB23tfjkxdTdaWjdxMmdLZ0syUktiaU9hSklYQmFGbzdkZGVtc09GRFB4ZzJTZ1k&usp=sharing

Add: Anyone interested in the EM thruster, feel free to check them out. -aero
« Last Edit: 06/22/2015 04:17 PM by aero »
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Offline SeeShells

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I like being able to get into the cavity to change the Microwave antenna and the endplates plus being able see inside the maelstrom of microwave cavity activity might prove to be a plus.

..

This is looking like it is going to be the best designed EM Drive test ever performed !

I will not be surprised if you see plasma inside the EM Drive, I look forward to seeing the experiment !

The RF feed location looks very important, based on aero's MEEP analysis.

Am I reading you correctly that you will have the ability to change the RF feed location at will by being able to get into the cavity?

Yep. That's a affirmative. I think this might be one of the lesser looked at and talked about aspects of the EMDrive. I have a dear friend who is a ham and my ex was as well (and had so many different antenna designs, smart man. I'm sorry he has passed on as he would have Loved this!) so by tech osmosis I'm a little up on antennas, have a local brain to pick, as on here.  I think it would be critical to be able to change the position as well as the shape.

With so much up in the air as to the why it does what it does I didn't want to lock myself into having no or little flexibility in the testing in cavity shape and antenna designs.

Shell

Offline aero

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I like being able to get into the cavity to change the Microwave antenna and the endplates plus being able see inside the maelstrom of microwave cavity activity might prove to be a plus.

..

This is looking like it is going to be the best designed EM Drive test ever performed !

I will not be surprised if you see plasma inside the EM Drive, I look forward to seeing the experiment !

The RF feed location looks very important, based on aero's MEEP analysis.

Am I reading you correctly that you will have the ability to change the RF feed location at will by being able to get into the cavity?

Yep. That's a affirmative. I think this might be one of the lesser looked at and talked about aspects of the EMDrive. I have a dear friend who is a ham and my ex was as well (and had so many different antenna designs, smart man. I'm sorry he has passed on as he would have Loved this!) so by tech osmosis I'm a little up on antennas, have a local brain to pick, as on here.  I think it would be critical to be able to change the position as well as the shape.

With so much up in the air as to the why it does what it does I didn't want to lock myself into having no or little flexibility in the testing in cavity shape and antenna designs.

Shell

You may also find the field patterns I linked above, interesting. I was surprised to see that the antenna location had such a dramatic effect, but on thinking about it I wonder why I didn't realize that would happen.
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Offline Rodal

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@ Dr. Rodal -

Attached are images of the Brady cavity and the Rodal cavity showing antenna location. Are you sure you want to place the antenna where EW had theirs placed? Before you answer that, take a look at the field patterns here:

Brady_corner_ant
https://drive.google.com/folderview?id=0B1XizxEfB23tfjBKSFF2dFp4WVV2MEZzNUtOU3NmdTZrQWd0dVo4WFIxcll0NDZEUjFXeEk&usp=sharing

and here:
Rodal_corner_ant
https://drive.google.com/folderview?id=0B1XizxEfB23tfjkxdTdaWjdxMmdLZ0syUktiaU9hSklYQmFGbzdkZGVtc09GRFB4ZzJTZ1k&usp=sharing

Add: Anyone interested in the EM thruster, feel free to check them out. -aero

I cannot access the links in your above message.  I get a screen stating "Permission required"

I could access the link you sent me previously in a personal message for the other runs.

What is the "Rodal cavity" ?

Offline Prunesquallor

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I like being able to get into the cavity to change the Microwave antenna and the endplates plus being able see inside the maelstrom of microwave cavity activity might prove to be a plus.

..

This is looking like it is going to be the best designed EM Drive test ever performed !

I will not be surprised if you see plasma inside the EM Drive, I look forward to seeing the experiment !

The RF feed location looks very important, based on aero's MEEP analysis.

Am I reading you correctly that you will have the ability to change the RF feed location at will by being able to get into the cavity?

Yep. That's a affirmative. I think this might be one of the lesser looked at and talked about aspects of the EMDrive. I have a dear friend who is a ham and my ex was as well (and had so many different antenna designs, smart man. I'm sorry he has passed on as he would have Loved this!) so by tech osmosis I'm a little up on antennas, have a local brain to pick, as on here.  I think it would be critical to be able to change the position as well as the shape.

With so much up in the air as to the why it does what it does I didn't want to lock myself into having no or little flexibility in the testing in cavity shape and antenna designs.

Shell

So for all the microwave gurus, what is the expected effect of a hexagonal as opposed to circular cross-section?
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Offline aero

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@ Dr. Rodal -

Attached are images of the Brady cavity and the Rodal cavity showing antenna location. Are you sure you want to place the antenna where EW had theirs placed? Before you answer that, take a look at the field patterns here:

Brady_corner_ant
https://drive.google.com/folderview?id=0B1XizxEfB23tfjBKSFF2dFp4WVV2MEZzNUtOU3NmdTZrQWd0dVo4WFIxcll0NDZEUjFXeEk&usp=sharing

and here:
Rodal_corner_ant
https://drive.google.com/folderview?id=0B1XizxEfB23tfjkxdTdaWjdxMmdLZ0syUktiaU9hSklYQmFGbzdkZGVtc09GRFB4ZzJTZ1k&usp=sharing

Add: Anyone interested in the EM thruster, feel free to check them out. -aero

I cannot access the links in your above message.  I get a screen stating "Permission required"

I could access the link you sent me previously in a personal message for the other runs.

What is the "Rodal cavity" ?

Its the Brady cavity extended (same taper) to small end diameter of 25% of the big end diameter. The long one in the images attached above.

I don't know why you can't click the links - I can. But then maybe Google remembers my computer. Does anyone else have a problem getting access to my Google drive data linked?

The linked folders contain complete sets of images, 16 cycles every 0.2 cycles. Here is one.

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Offline SeeShells

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I like being able to get into the cavity to change the Microwave antenna and the endplates plus being able see inside the maelstrom of microwave cavity activity might prove to be a plus.

..

This is looking like it is going to be the best designed EM Drive test ever performed !

I will not be surprised if you see plasma inside the EM Drive, I look forward to seeing the experiment !

The RF feed location looks very important, based on aero's MEEP analysis.

Am I reading you correctly that you will have the ability to change the RF feed location at will by being able to get into the cavity?

Yep. That's a affirmative. I think this might be one of the lesser looked at and talked about aspects of the EMDrive. I have a dear friend who is a ham and my ex was as well (and had so many different antenna designs, smart man. I'm sorry he has passed on as he would have Loved this!) so by tech osmosis I'm a little up on antennas, have a local brain to pick, as on here.  I think it would be critical to be able to change the position as well as the shape.

With so much up in the air as to the why it does what it does I didn't want to lock myself into having no or little flexibility in the testing in cavity shape and antenna designs.

Shell

You may also find the field patterns I linked above, interesting. I was surprised to see that the antenna location had such a dramatic effect, but on thinking about it I wonder why I didn't realize that would happen.
I tried to look at them but need access and sent you a request from my google account just a bit ago.
Shell

Offline rfmwguy

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Yep. That's a affirmative. I think this might be one of the lesser looked at and talked about aspects of the EMDrive. I have a dear friend who is a ham and my ex was as well (and had so many different antenna designs, smart man. I'm sorry he has passed on as he would have Loved this!) so by tech osmosis I'm a little up on antennas, have a local brain to pick, as on here.  I think it would be critical to be able to change the position as well as the shape.

With so much up in the air as to the why it does what it does I didn't want to lock myself into having no or little flexibility in the testing in cavity shape and antenna designs.

Shell

So for all the microwave gurus, what is the expected effect of a hexagonal as opposed to circular cross-section?

Field wise, I do not know, thermal wise, a potential for some thermal focus along the seams, but this is going to be way interesting! Nice call Shell...

Offline SeeShells

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I like being able to get into the cavity to change the Microwave antenna and the endplates plus being able see inside the maelstrom of microwave cavity activity might prove to be a plus.

..

This is looking like it is going to be the best designed EM Drive test ever performed !

I will not be surprised if you see plasma inside the EM Drive, I look forward to seeing the experiment !

The RF feed location looks very important, based on aero's MEEP analysis.

Am I reading you correctly that you will have the ability to change the RF feed location at will by being able to get into the cavity?

Yep. That's a affirmative. I think this might be one of the lesser looked at and talked about aspects of the EMDrive. I have a dear friend who is a ham and my ex was as well (and had so many different antenna designs, smart man. I'm sorry he has passed on as he would have Loved this!) so by tech osmosis I'm a little up on antennas, have a local brain to pick, as on here.  I think it would be critical to be able to change the position as well as the shape.

With so much up in the air as to the why it does what it does I didn't want to lock myself into having no or little flexibility in the testing in cavity shape and antenna designs.

Shell

So for all the microwave gurus, what is the expected effect of a hexagonal as opposed to circular cross-section?

Yes, please speak up, I'd love to hear your thoughts.

Shell

Offline Rodal

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Its the Brady cavity extended (same taper) to small end diameter of 25% of the big end diameter. The long one in the images attached above.

I don't know why you can't click the links - I can. But then maybe Google remembers my computer. Does anyone else have a problem getting access to my Google drive data linked?

The linked folders contain complete sets of images, 16 cycles every 0.2 cycles. Here is one.

On the Google Drive: it looks like you need to set it so that anybody can look at it without receiving permission.

///////////////////

On the antenna placement, it looks awfully unsymmetric.

Is it a TM or a TE mode?

If it is from the early period transient before it settled into a symmetric steady state pattern , no problem.

Otherwise, it looks like what is needed is to have a MEEP study of optimal antenna placements :)
« Last Edit: 06/22/2015 04:49 PM by Rodal »

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..

...

So for all the microwave gurus, what is the expected effect of a hexagonal as opposed to circular cross-section?

Field wise, I do not know, thermal wise, a potential for some thermal focus along the seams, but this is going to be way interesting! Nice call Shell...

I was thinking that the antenna placement and design if a rubber duckie stick type, loop (got  interesting thoughts here, my ex came up with the loop antenna used in the astronauts helmets after the first problems with the whips hitting the side walls of the first LEM landing and blanking out. The loop has a nice null in the center so the astronauts wouldn't get fried with microwaves). And even thought on a highly modified loopstick antenna with a ferrite iron core and to place in the center of the cavity. Sounds cool doesn't it as this has to do with what WarpTech was thinking about on the Magnetic actions within the Cavity.

I hope the heating with the slight bend in the sides is minimal. I'm thinking it might not interact at all but we will see.

Shell

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Offline Rodal

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@ Dr. Rodal -

Attached are images of the Brady cavity and the Rodal cavity showing antenna location. Are you sure you want to place the antenna where EW had theirs placed? Before you answer that, take a look at the field patterns here:

Brady_corner_ant
https://drive.google.com/folderview?id=0B1XizxEfB23tfjBKSFF2dFp4WVV2MEZzNUtOU3NmdTZrQWd0dVo4WFIxcll0NDZEUjFXeEk&usp=sharing

and here:
Rodal_corner_ant
https://drive.google.com/folderview?id=0B1XizxEfB23tfjkxdTdaWjdxMmdLZ0syUktiaU9hSklYQmFGbzdkZGVtc09GRFB4ZzJTZ1k&usp=sharing

Add: Anyone interested in the EM thruster, feel free to check them out. -aero

I cannot access the links in your above message.  I get a screen stating "Permission required"

I could access the link you sent me previously in a personal message for the other runs.

What is the "Rodal cavity" ?

Its the Brady cavity extended (same taper) to small end diameter of 25% of the big end diameter. The long one in the images attached above.

I don't know why you can't click the links - I can. But then maybe Google remembers my computer. Does anyone else have a problem getting access to my Google drive data linked?

The linked folders contain complete sets of images, 16 cycles every 0.2 cycles. Here is one.
OK, now I can access your pictures on Google Drive (don't know what you changed).



It looks to me that this is a 2-D model, and that this field cannot occur in the 3-D axisymmetric EM Drive

Please let me know whether these are 2-D models.  If so they are unrepresentative, as those patterns cannot occur in a rotationally symmetric EM Drive. They can only occur on a trapezium box (which is the 2-D model)


This is an interesting exercise to show the problem with 2-D modeling.
« Last Edit: 06/22/2015 05:19 PM by Rodal »

Offline sghill

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Time to start my build.

Godspeed John Glenn!
Bring the thunder Elon!

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