Author Topic: EM Drive Developments - related to space flight applications - Thread 3  (Read 1877171 times)

Offline aero

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Been following this thread for a few weeks, decided to hop in to help if I could.

Aero, do you need only the most recent MEEP package?
I was going to go ahead and compile it from source for you but I found:
http://ab-initio.mit.edu/wiki/index.php/Meep_Download

According to the wiki, they have a precompiled source package available:
"apt-get install meep h5utils"

There is also a parallel source file:
"apt-get install meep-mpi"

If you need other packages compiled with it or the OpenMPI version, I will see what I can do.

I saw that one as well and was going to try it out.
If you want to help, you could try to create a Ubuntu package for Meep as aero uses Ubuntu (and so am I and a few others).  http://packaging.ubuntu.com/html/

I also do not know which compiler / optimization the source code would support, but you may want to explore recompiling the source using different compilers (gcc / LLVM / ICC / VC ...) and different optimization flags.  It can also be that the source code could enjoy being made more compiler agnostic.

There is already an Ubuntu distrubtion available.

http://ab-initio.mit.edu/wiki/index.php/Meep_download

Then look down at the "Precompiled Meep packages for Debian and Ubuntu" section. It's pretty easy. There is even an MPI enabled version.

That is the one that I already use. It is an old version. And try installing the MPI enabled version, if you can find anything more than the promise.
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Offline aero

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...
I suggest that you may wish to look at some of the fields generated with the Gaussian source as they appear to be much stronger than those calculated using the continuous source. Csv files are available for the big end base view, and I'll see about creating csv files for the "transverse" view.

Regarding your observation, "observe that there are no field values outside the circle" I disagree. If there were no fields, the background would show as black, I think. There is some energy there, just the fields are so weak compared to the fields inside that they are not differentiated by color from some very small value.

Nope.:  ALL that is shown is inside the boundary condition.  If you are inputting a finite difference mesh outside the BC,  Meep is ignoring those nodes.  Since you are only exciting the inside with RF, and you have BC, Meep has to ignore those nodes outside the BC, otherwise the solution would be ill conditioned


All the points in the csv file are inside the circle.  The circle is mapped into the square.

I choose to plot only 10 contours for clarity.


These views are rotated 90 degrees from your views.

I confirm that the fractals are a result of the very coarse mesh you are using:  the Ez and Ey fields should be zero at the base. They are not zero:  they are about 10 times smaller in magnitude only.

All numbers are very small: the highest magnitude numbers are about 10^(-13) !

I don't think so. Let me make, or find a clear example data set for you to look at.
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Offline zellerium

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Hey, quick question to those savvy with microwaves:

We would like to determine how well the magnetron is matched with the manufacturers microwave box so that we have a baseline for safe operating impedance of the magnetron. My idea is to put several temperature probes on the magnetron outside core and heat sink fins and log data. Our probes max out at 130 C, does anyone have any idea how quickly an uncooled magnetron will get there?

This method would allow a simple impedance measurement so that any subsequent cavity we create can be compared to the original microwave. [I'd be making the assumption that the manufacturer created a cavity that is well matched to the magnetron to minimize reflected power. Is this a valid assumption? ]

Any thoughts, concerns, suggestions?


Kurt
 
The reflected wave would likely damage the megnetron before the temperature sensors registered a high temperature.   It is better to design the feedline so that the return wave can't get back to the magneron and then match the cavity to minimize the return wave.   One photo that was posted awhile back showed a feedline with an inline waveguide circulator.   It may have been from the Chinese experiment.   It could easily be replicated by a machine shop.

Actually, the temperature sensors performed well and registered a 70 C increase on the core after running the magnetron with an empty microwave for 20 seconds. Heat sink and delivery waveguide temperature increased by about 30 and 10 C respectively, but were very delayed compared to the core. Putting a dielectric inside the microwave definitely slowed the rate of temperature increase, but not significantly. Makes sense that Shawyer decided on a water cooled magnetron...

We are going to contruct an adjustable system and use a VNA to determine the necessary matching adjustments.

How hot can a magnetron get before it is 'damaged'?
I imagine all internal parts are expanding, I wonder how long it takes for parts to plastically deform.
 

Online Rodal

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Been following this thread for a few weeks, decided to hop in to help if I could.

Aero, do you need only the most recent MEEP package?
I was going to go ahead and compile it from source for you but I found:
http://ab-initio.mit.edu/wiki/index.php/Meep_Download

According to the wiki, they have a precompiled source package available:
"apt-get install meep h5utils"

There is also a parallel source file:
"apt-get install meep-mpi"

If you need other packages compiled with it or the OpenMPI version, I will see what I can do.

I saw that one as well and was going to try it out.
If you want to help, you could try to create a Ubuntu package for Meep as aero uses Ubuntu (and so am I and a few others).  http://packaging.ubuntu.com/html/

I also do not know which compiler / optimization the source code would support, but you may want to explore recompiling the source using different compilers (gcc / LLVM / ICC / VC ...) and different optimization flags.  It can also be that the source code could enjoy being made more compiler agnostic.

There is already an Ubuntu distrubtion available.

http://ab-initio.mit.edu/wiki/index.php/Meep_download

Then look down at the "Precompiled Meep packages for Debian and Ubuntu" section. It's pretty easy. There is even an MPI enabled version.

That is the one that I already use. It is an old version. And try installing the MPI enabled version, if you can find anything more than the promise.

These are 3D plots of the same data shown previously in ContourPlots.

Need to see the trapezium views.  3 Fields at the Base are supposed to be zero.  The bases not interesting to look at. 
« Last Edit: 07/01/2015 01:15 AM by Rodal »

Online Rodal

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You are talking about doing a numerical analysis here with really tiny numbers   10^-13  ....

The numbers were 10^-8 before (without the Gaussian noise).

Now that you added Gaussian noise they are much smaller:  10^13  (down by 5 orders of magnitude).

Base circular cross-sections (you chose instead of trapezium) are the worst cross sections to look at:

1) Ez must be zero at the base (it isn't which means that there a boundary condition accuracy problem)

2) Ey must be zero at the base (it isn't which means that there a boundary condition accuracy problem)

3) Hx must be zero at the base (it isn't which means that there a boundary condition accuracy problem)

So three fields must be zero everywhere at the bases.

If you plot the trapezium cross-section, the BC is enforced only at the walls.

The fields that are nonzero (shown in the plots above) are only 10 times larger than the fields that are supposed to be zero

This tells you that any number that is 1/10th of the maximum could be zero, that's the level of numerical uncertainty in the analysis.
« Last Edit: 07/01/2015 01:13 AM by Rodal »

Offline aero

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Here are the  field patterns for NSF-1701 using a Gaussian source. Take a look at the difference between a noisy source and an ideal continuous source.
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Online Rodal

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Here are the  field patterns for NSF-1701 using a Gaussian source. Take a look at the difference between a noisy source and an ideal continuous source.

Well, it would be nice if you or anybody else would plot your csv files and show how can they be anything resembling the other views.  Clearly (to me at least) the csv files are not the same thing.  As to what is the relation between the csv files and the images in NSF-1701, who knows ?

There are no circular boundaries on the csv files.  The numbers in them are tiny 10^-13. 

Anybody can look at the numbers in the csv files: they are 10^-13 for the Gauss files, 10^-8 for the "final" labeled-ones (all it takes is to take a gander at the csv files with Excel)


Something is amiss here with the csv files and their relationship (if any) to the images the program outputs.

The following can be shown from the csv files:

1)  the "fractal" looking images are all associated with smaller numbers than those that do not look fractal

2) Fields that are supposed to be exactly zero at the base (Ez, Ey, and Hx) are not zero, they are 10% of the highest numbers in the csv files, which shows that everything 10% or lower than the max could be zero, for all one knows.

These two images don't look at all like the same thing.  Something is amiss with the csv files
« Last Edit: 07/01/2015 02:39 AM by Rodal »

Offline quixote

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Been following this thread for a few weeks, decided to hop in to help if I could.

Aero, do you need only the most recent MEEP package?
I was going to go ahead and compile it from source for you but I found:
http://ab-initio.mit.edu/wiki/index.php/Meep_Download

According to the wiki, they have a precompiled source package available:
"apt-get install meep h5utils"

There is also a parallel source file:
"apt-get install meep-mpi"

If you need other packages compiled with it or the OpenMPI version, I will see what I can do.

I saw that one as well and was going to try it out.
If you want to help, you could try to create a Ubuntu package for Meep as aero uses Ubuntu (and so am I and a few others).  http://packaging.ubuntu.com/html/

I also do not know which compiler / optimization the source code would support, but you may want to explore recompiling the source using different compilers (gcc / LLVM / ICC / VC ...) and different optimization flags.  It can also be that the source code could enjoy being made more compiler agnostic.

There is already an Ubuntu distrubtion available.

http://ab-initio.mit.edu/wiki/index.php/Meep_download

Then look down at the "Precompiled Meep packages for Debian and Ubuntu" section. It's pretty easy. There is even an MPI enabled version.

That is the one that I already use. It is an old version. And try installing the MPI enabled version, if you can find anything more than the promise.

It's bleeding edge, but there's these packages for 1.3. I imagine most people will want to select amd64 at the bottom.

https://packages.debian.org/sid/libmeep-openmpi8


Offline aero

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Been following this thread for a few weeks, decided to hop in to help if I could.

Aero, do you need only the most recent MEEP package?
I was going to go ahead and compile it from source for you but I found:
http://ab-initio.mit.edu/wiki/index.php/Meep_Download

According to the wiki, they have a precompiled source package available:
"apt-get install meep h5utils"

There is also a parallel source file:
"apt-get install meep-mpi"

If you need other packages compiled with it or the OpenMPI version, I will see what I can do.

I saw that one as well and was going to try it out.
If you want to help, you could try to create a Ubuntu package for Meep as aero uses Ubuntu (and so am I and a few others).  http://packaging.ubuntu.com/html/

I also do not know which compiler / optimization the source code would support, but you may want to explore recompiling the source using different compilers (gcc / LLVM / ICC / VC ...) and different optimization flags.  It can also be that the source code could enjoy being made more compiler agnostic.

There is already an Ubuntu distrubtion available.

http://ab-initio.mit.edu/wiki/index.php/Meep_download

Then look down at the "Precompiled Meep packages for Debian and Ubuntu" section. It's pretty easy. There is even an MPI enabled version.

That is the one that I already use. It is an old version. And try installing the MPI enabled version, if you can find anything more than the promise.

It's bleeding edge, but there's these packages for 1.3. I imagine most people will want to select amd64 at the bottom.

https://packages.debian.org/sid/libmeep-openmpi8

Now that looks promising. Of course I can't modify the source, oh well - probably wouldn't anyway except for fixes/upgrades from the developers.
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Offline arc

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A quick and rough set of plots, looking for interesting things;

Rotate to full X-aixs:Z-axis:Y=0 view: Reflection and inverted symmetry exists through the middle


ex gaus base: similar symmetry

Rotate 90: view from Y-axis straight along X-axis


Confirmation for @Rodal image: Your csv-matrix decode image (ex-gaus-base) is correct
« Last Edit: 07/01/2015 09:17 PM by arc »

Offline TheTraveller

Should be home tomorrow and back online early next week. Have a new high performance 2.45GHz frustum design (Df 0.92) and have moved to a rotary test rig as there are issues using scales of any kind. Also working on an Engineers explanation of How and Why an EMDrive works and does not violate either CofM or CofE. Roger Shawyer has agreed to check it for errors. Will explain more later.

Attached are the original scan data on my Prostate cancer. So Yes it is very real. The white spot are cross sections of the cancer. BTW my PSA at the time was 3.7, which is inside the normal range for my age and would normally indicate no prostate cancer. My docs said 30% of prostate cancers have low PSA reading.

A man's prostate is normally the size of a walnut. My ball of confused prostate and cancer was 5cm in dia mid Dec 14 and 9cm when removed Jun 2015.

Guys GET YOUR PROSTATE CHECKED.

Apologies for elements of this post being Off Topic.
"As for me, I am tormented with an everlasting itch for things remote. I love to sail forbidden seas.
Herman Melville, Moby Dick

Offline zen-in

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Hey, quick question to those savvy with microwaves:

...

Our probes max out at 130 C, does anyone have any idea how quickly an uncooled magnetron will get there?

...

Any thoughts, concerns, suggestions?


Kurt
 
The reflected wave would likely damage the megnetron before the temperature sensors registered a high temperature.   
...

Actually, the temperature sensors performed well and registered a 70 C increase on the core after running the magnetron with an empty microwave for 20 seconds. Heat sink and delivery waveguide temperature increased by about 30 and 10 C respectively, but were very delayed compared to the core. Putting a dielectric inside the microwave definitely slowed the rate of temperature increase, but not significantly. Makes sense that Shawyer decided on a water cooled magnetron...

We are going to contruct an adjustable system and use a VNA to determine the necessary matching adjustments.

How hot can a magnetron get before it is 'damaged'?
I imagine all internal parts are expanding, I wonder how long it takes for parts to plastically deform.
 

I don't know how magnetrons are constructed.  They can probably withstand a temperature above 100 C without getting damaged.   Indium, which is used to solder glass to metal,  has a melting point of 157 C.  However if BeO is used instead of glass then Indium would not be used so the max operating temperature could be much higher.   My guess though is that high reflected power could cause internal arcing and would not cause a sharp rise in temperature before destroying the magnetron.   

The device I saw in a picture from the Chinese experiment (in thread 2) was a waveguide isolator.   It is designed to allow the RF to just go in one direction thru it.  It is a good idea to use something like that because the RF then has no where to go except into the cavity.

Offline lmbfan

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I have compiled and tested out Meep on Cygwin.  I may be able help anyone who wants to figure out how to compile on Windows using Cygwin (I have some experience with programming, but I am no expert).  I can also run any .ctl files if need be.

Just send me a message if you need help or have a .ctl file to use.

Offline Chrochne

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Should be home tomorrow and back online early next week. Have a new high performance 2.45GHz frustum design (Df 0.92) and have moved to a rotary test rig as there are issues using scales of any kind. Also working on an Engineers explanation of How and Why an EMDrive works and does not violate either CofM or CofE. Roger Shawyer has agreed to check it for errors. Will explain more later.

Attached are the original scan data on my Prostate cancer. So Yes it is very real. The white spot are cross sections of the cancer. BTW my PSA at the time was 3.7, which is inside the normal range for my age and would normally indicate no prostate cancer. My docs said 30% of prostate cancers have low PSA reading.

A man's prostate is normally the size of a walnut. My ball of confused prostate and cancer was 5cm in dia mid Dec 14 and 9cm when removed Jun 2015.

Guys GET YOUR PROSTATE CHECKED.

Apologies for elements of this post being Off Topic.

Good to see you back Mr. Traveller. I wish you speedy recovery.

I am also glad to see that Mr. Roger Shawyer is checking the debate here. We also know that NASA guys are also listening and checking. Also the group here that leads the debate are incredible in their research and ideas.

I congratulate you all to create such a hub of ideas. It is inspirational for young people as me.
Congratulations also goes to moderators for their patience.


Online Rodal

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Concept drawing previously posted by Star-Drive (Paul March) for a magnetron feeding RF to a water-cooled EM Drive at the center of the small base of the EM Drive.

EDIT: Paul March also uses spherical (instead of flat) ends, and places the magnetron at the apex of the cone, extending the EM drive towards the minimum small base diameter possible to accommodate the magnetron.  Not concerned about "cut-off" nonsense limits based on cylindrical waveguides (that do not apply to truncated cones). He also plans to excite the lowest natural frequency TM010, which has the highest amplitude of all modes.

Also his design to use the present NASA frustum with an internal partition to resonate at 2.45 GHz in the lower mode, higher amplitude TE011 for the Interferometer tests.
EM Drive testers could use a similar partition to investigate resonance at lower modes, which should exhibit higher amplitude, without needing to cut the EM Drive permanently
« Last Edit: 07/01/2015 01:16 PM by Rodal »

Offline SeeShells

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After some digging I've finally settled on a antenna. It will be placed through the small endcap which will act as a ground plane as well. Nice helical pattern and about 8 db of gain. An axial-mode quadrifilar helical antenna putting out a circularly polarized field. I wrote the company asking if they wanted to donate one, haven't heard back yet and If I don't I'll just make one.
http://orbanmicrowave.com/thebasicsofquadrifilarantennas/

Offline SeeShells

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Concept drawing previously posted by Star-Drive (Paul March) for a magnetron feeding RF to a water-cooled EM Drive at the center of the small base of the EM Drive
Love this design. Can't afford it but like it.

Edit: I've been calculating and digging and researching for days on how to put an antenna into the my copper Frustum and it's pretty much been designed by Dr. Paul March already. I did't see this until this morning but I think it's a beautiful idea. He probably went "Oh no problemo, we can do this off the top of his head". The main difference is I'm going to circularly polarize the field which is something I want to do. 
« Last Edit: 07/01/2015 01:39 PM by SeeShells »

Online Rodal

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Should be home tomorrow and back online early next week. Have a new high performance 2.45GHz frustum design (Df 0.92) and have moved to a rotary test rig as there are issues using scales of any kind. Also working on an Engineers explanation of How and Why an EMDrive works and does not violate either CofM or CofE. Roger Shawyer has agreed to check it for errors. Will explain more later.

Attached are the original scan data on my Prostate cancer. So Yes it is very real. The white spot are cross sections of the cancer. BTW my PSA at the time was 3.7, which is inside the normal range for my age and would normally indicate no prostate cancer. My docs said 30% of prostate cancers have low PSA reading.

A man's prostate is normally the size of a walnut. My ball of confused prostate and cancer was 5cm in dia mid Dec 14 and 9cm when removed Jun 2015.

Guys GET YOUR PROSTATE CHECKED.

Apologies for elements of this post being Off Topic.

Sorry to hear about what you had to go through and hoping for a quick recovery.

If you care to discuss further, it would be helpful for others to know what symptoms did you experience that gave you a warning sign.

////

QUESTION: Concerning your rotary test rig, are you planning to use an air bearing set-up, like Shawyer's ?

Offline SeeShells

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Concept drawing previously posted by Star-Drive (Paul March) for a magnetron feeding RF to a water-cooled EM Drive at the center of the small base of the EM Drive.

EDIT: Paul March also uses spherical (instead of flat) ends, and places the magnetron at the apex of the cone, extending the EM drive towards the minimum small base diameter possible to accommodate the magnetron.  Not concerned about "cut-off" nonsense limits based on cylindrical waveguides (that do not apply to truncated cones). He also plans to excite the lowest natural frequency TM010, which has the highest amplitude of all modes.

Also his design to use the present NASA frustum with an internal partition to resonate at 2.45 GHz in the lower mode, higher amplitude TE011 for the Interferometer tests.
EM Drive testers could use a similar partition to investigate resonance at lower modes, which should exhibit higher amplitude, without needing to cut the EM Drive permanently

That can be easy enough to test with my split design that allowed for inserts along the cavity.

Offline TheTraveller

Should be home tomorrow and back online early next week. Have a new high performance 2.45GHz frustum design (Df 0.92) and have moved to a rotary test rig as there are issues using scales of any kind. Also working on an Engineers explanation of How and Why an EMDrive works and does not violate either CofM or CofE. Roger Shawyer has agreed to check it for errors. Will explain more later.

Attached are the original scan data on my Prostate cancer. So Yes it is very real. The white spot are cross sections of the cancer. BTW my PSA at the time was 3.7, which is inside the normal range for my age and would normally indicate no prostate cancer. My docs said 30% of prostate cancers have low PSA reading.

A man's prostate is normally the size of a walnut. My ball of confused prostate and cancer was 5cm in dia mid Dec 14 and 9cm when removed Jun 2015.

Guys GET YOUR PROSTATE CHECKED.

Apologies for elements of this post being Off Topic.

Sorry to hear about what you had to go through and hoping for a quick recovery.

If you care to discuss further, it would be helpful for others to know what symptoms did you experience that gave you a warning sign.

////

QUESTION: Concerning your rotary test rig, are you planning to use an air bearing set-up, like Shawyer's ?

My GP talked me into letting him do a DRE (Digital Rectal Exam) as part of a yearly checkup despite my PSA being 3.7. The digital bit is the doctors gloved finger. He found the left side of my prostate was enlarged and sent me to have a prostate biopsy, where they take 12 needle biopsies through the rectal wall. Quick and painless. 20 minutes and they were done. Told me he expected to see nothing as my blood work was excellent and showed no signs of anything. When he got the results, his face was white. 5 of the 6 biopsies of my left prostate had Gleason 8 & 9 cores. 10 is the tops. Means almost the entire left side of my prostate was pure high level cancer cells, yet my PAS was only 3.7.

After the scan the picture was clearer that I had a 5cm fuzzy ball of prostate cancer cells growing inside me and it had exited the prostate and was growing in surrounding tissues.

Had no symptoms. Wee and bowel actions were normal. No suspicious pains. My doc told me he wished he was in my condition when he was my age (late 60s). I'm not on any drugs or medications. Eat very healthy, only fresh fruits and veggies, some meat, mostly salmon. Ave 1 glass of good Aussie Shiraz per day, max 4 in any day. Blood pressure, fasting and non fasting glucose excellent, cholesterol excellent, heart rate excellent. Maybe carrying a bit more weight than I would like but doc says I'm fine, just walk a bit more.

So yes a very big shock to both me and my GP that they took a 9cm ball of cancer cells out of my gut.

As I said, GET YOURSELF CHECKED.

========================

As for the test rig, will use a DIY magnetic thrust bearing as the max load will be around 10kg as against SPR's 100kg test load. Will have 1,000s of output pulses per rev to enable easy accel calcs. All data logged. Will not have adjustable load as such but can vary the mass to get different accel as per A = F/M.

When SPR did this they found the KE transferred to the 100kg load mass was what which was drawn from the power supply, adjusting for losses.

As SPR have not yet published this data, my tests may be the 1st to show the KE gain by the load is sourced from the power supply, which eliminates ZPE as the energy source. Can't do this with scales.

I need to stop as phone battery is almost dead and the nurse will be around any minute. Will be good to be home again.
« Last Edit: 07/01/2015 02:02 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

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