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#200 by OttO on 10 Aug, 2015 13:44
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I was asking myself how long it would take to empty the frustum of the energy stored, now I know, not long
Extracting microwave energy from a cavity by mode conversion at a coupling window
http://rd.springer.com/article/10.1134/1.1259080
"It is shown that microwave rf pulse compressors with copper storage cavities and energy extraction by mode conversion at a coupling window can provide gains of 5–13 dB with output signal durations of 20–150 ns and peak powers of 5–10 MW in the 3-cm band and 50–100 MW in the 10-cm band. " -
#201 by SeeShells on 10 Aug, 2015 13:53
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Off topic alert - Today, I turned the big six-zero; a milestone birthday. Which should be used to convince others that one can still think, dream and build well into their senior era. So many companies and institutions look to replace older folks once they turn 50...I know from experience. I also know that its a waste of talent to do this.
And a very happy birthday from another of the older generation. As my mom said to me many times Dave. Make it so!
So, here's to the older generation still plugging away at science. How I wish something like this project were around when I was much younger. THAT should be a message to the young folks out there to get involved in science early. Push the envelope, think outside the box, do something different...who knows, what you may come up with could change the world.
Onward and upward - Dave (rfmwguy)
Michelle -
#202 by SeeShells on 10 Aug, 2015 13:57
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I was asking myself how long it would take to empty the frustum of the energy stored, now I know, not long
Perfect! Was looking this morning at how much the mode changes could kill off the Q and the time frame needed. Thanks
Extracting microwave energy from a cavity by mode conversion at a coupling window
http://rd.springer.com/article/10.1134/1.1259080
"It is shown that microwave rf pulse compressors with copper storage cavities and energy extraction by mode conversion at a coupling window can provide gains of 5–13 dB with output signal durations of 20–150 ns and peak powers of 5–10 MW in the 3-cm band and 50–100 MW in the 10-cm band. "
back to reading and lurking. -
#203 by ElizabethGreene on 10 Aug, 2015 14:20
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Has anyone, in the thousands of posts here, calculated how much water (gm/s) it would take to generate X N of thrust by evaporation and steam jetting?
I can do it, but require more data. It's F= (p_exit - p_0) A_e + _mdot V_e
The terms are, in order, pressure at the nozzle, ambient pressure, Area of the nozzle exit, Mass flow rate (in kilograms per second), and exit velocity.
For forces ~ 1 N in air I "feel" like...
A.) You would notice it.
B.) The cavity would exhaust the available water vapor in the cavity very rapidly.
For short bursts of power or muN force levels steam jetting or hot air jets do "feel" like realistic sources of experimental error. Putting symmetrical (relatively) big holes in the sidewalls and doing longer runs should reduce these by maximizing Ae, minimizing p, and exhausting the available water vapor.
I have similar concerns with hot air in the cavity causing ballooning error. I don't know how to eliminate that effect while retaining a gas-filled cavity. Advice in that direction would be appreciated. -
#204 by aero on 10 Aug, 2015 14:24
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Off topic alert - Today, I turned the big six-zero; a milestone birthday. Which should be used to convince others that one can still think, dream and build well into their senior era. So many companies and institutions look to replace older folks once they turn 50...I know from experience. I also know that its a waste of talent to do this.
So, here's to the older generation still plugging away at science. How I wish something like this project were around when I was much younger. THAT should be a message to the young folks out there to get involved in science early. Push the envelope, think outside the box, do something different...who knows, what you may come up with could change the world.
Onward and upward - Dave (rfmwguy)
Happy birthday, youngster. -
#205 by tleach on 10 Aug, 2015 14:33
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Hi Thor,
No, 30% is the amount of time power is at 100%, so it will "pulse" at full power for 30% of the time.
Sorry, busy weekend! Happy birthday!
Ok, right. That's makes the spreadsheet spit out (assuming 64% efficiency in converting electrical input into RF) a figure of up to 100.93mN or 144.71 mN for 30% of the time. -
#206 by OttO on 10 Aug, 2015 14:38
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Conical Waves Producing Longitudinal Power Flows
http://rd.springer.com/article/10.1134/1.1307823#page-1
"A conical electromagnetic wave converging to its axis is studied theoretically. It is
demonstrated that the wave produces an intense self-accelerating flow of energy
(momentum)"
Seem to me a bit strange but... [EDIT] Do not stay in front, very barsoonian
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#207 by Rodal on 10 Aug, 2015 14:40
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Hi Thor,
No, 30% is the amount of time power is at 100%, so it will "pulse" at full power for 30% of the time.
Sorry, busy weekend! Happy birthday!
Ok, right. That's makes the spreadsheet spit out (assuming 64% efficiency in converting electrical input into RF) a figure of up to 100.93mN or 144.71 mN for 30% of the time.
Please notice that McCulloch's formula is completely unable to distinguish between TM (transverse magnetic) from TE (transverse electric) modes. Actually McCulloch's formula completely ignores the mode shape (it ignores not only whether TE or TM but also it ignores the quantum mode shape numbers m,n,p). This is a weakness in McCulloch's formula (not present in Notsosureofit's formula that does take into account the mode shapes).
Those claiming much larger thrust and thrust/InputPower claim to use TE modes: Shawyer and Yang.
NASA also reported much larger thrust/InputPower when using TE modes but could not excite it consistently so they switched to TM modes.
So, there is considerable uncertainty when predicting thrust with a formula that ignores the mode shape of EM Drive operation.
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#208 by SeeShells on 10 Aug, 2015 14:54
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Nice work aero. I like this and your run file is very easy to read.
I organized the images in a equal grid http://i.imgur.com/0S3xpKH.jpg
My question is, are the vertical columns when arranged like this showing the same time stamp through the frustum for the sample on the waveform showing the mode?
Shell
First column
ex.t00
ey.t00
ez.000
etc....I took a break today and let my computer run 64 cycles of the Shell conic frustum cavity model. The png views and csv data of the final 14 time slices is available here. To me, it does look to be much more "converged" than 32 cycle runs.
https://drive.google.com/folderview?id=0B1XizxEfB23tfmVCZlhnNUVtTGRoTTlZSGJiT3ZfSHBvYnNELUc1WlN0Sk15ZDZud3pSWmM&usp=sharing
Please read the data description file for the details of the run. -
#209 by aero on 10 Aug, 2015 15:16
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Thanks.
Yes, all of the slices labelled t 00 are taken just after the 62.7th cycle, those labelled t 01 just after the 62.8th cycle and so forth, up to the slice labelled t13 which is taken at the end of the run, at the 64th cycle.Nice work aero. I like this and your run file is very easy to read.
I organized the images in a equal grid http://i.imgur.com/0S3xpKH.jpg
My question is, are the vertical columns when arranged like this showing the same time stamp through the frustum for the sample on the waveform showing the mode?
Shell
First column
ex.t00
ey.t00
ez.000
etc....I took a break today and let my computer run 64 cycles of the Shell conic frustum cavity model. The png views and csv data of the final 14 time slices is available here. To me, it does look to be much more "converged" than 32 cycle runs.
https://drive.google.com/folderview?id=0B1XizxEfB23tfmVCZlhnNUVtTGRoTTlZSGJiT3ZfSHBvYnNELUc1WlN0Sk15ZDZud3pSWmM&usp=sharing
Please read the data description file for the details of the run. -
#210 by tleach on 10 Aug, 2015 15:25
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Please notice that McCulloch's formula is completely unable to distinguish between TM (transverse magnetic) from TE (transverse electric) modes. Actually McCulloch's formula completely ignores the mode shape (it ignores not only whether TE or TM but also it ignores the quantum mode shape numbers m,n,p). This is a weakness in McCulloch's formula (not present in Notsosureofit's formula that does take into account the mode shapes).
Those claiming much larger thrust and thrust/InputPower claim to use TE modes: Shawyer and Yang.
NASA also reported much larger thrust/InputPower when using TE modes but could not excite it consistently so they switched to TM modes.
So, there is considerable uncertainty when predicting thrust with a formula that ignores the mode shape of EM Drive operation.
The derivation (F = 6PQL/c * [1/(L+4wb) - 1/(L+4ws) ] which I found on http://physicsfromtheedge.blogspot.co.uk/2015/02/mihsc-vs-emdrive-data-3d.html) that I'm using in my spreadsheet doesn't take into account the input frequency of the radiation either, just the Power and the "Q".
EDIT: If I get a chance tonight I'll try to add Notsosureofit's formula to my spreadsheet and see what happens -
#211 by Mulletron on 10 Aug, 2015 16:21
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Frobnicat, that smiley was perfect. Definitely a WTF moment.
LOL...yep
was perfect. Funny how people jump to extreme applications without due-diligence on prototypes...i.e. replication, explanation and 3rd party verification. That leads to speculation on whether its all a funding scheme.
On NSF-1701, if I've detected any force whatsoever, I'll try and figure out why only to a point. After that, I would prefer to offer it (for free) to a reputable institution that is willing to duplicate tests under (expensive) laboratory conditions.
Of course, if they break it...that would spoil my day
Is it legally possible and ethically right for us to try and open source this Resonant Cavity Thruster? I mean seriously, nobody owns the wheel. If this approach proves to be a viable means for propellantless propulsion, then the impact factor is no less important.
For Shawyer to try and patent this before there was even a dream of a viable commercial product is ludicrous.
He should have opened it up to research at the beginning.
Based on what I know, the current iteration is obviously not viable.
So, what do we have now that is truly unique and novel with which we can package up and give to the world?
If members of the public are able to own a personal stake in something as evolutionary as this, some will gladly invest enormous amounts of effort, even with no guarantee of any financial reward or any success; like us.
So can it be done? Should it be done? If so, we need help...
We just have to make it roll. The rest is history.
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#212 by Rodal on 10 Aug, 2015 16:36
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Please notice that McCulloch's formula is completely unable to distinguish between TM (transverse magnetic) from TE (transverse electric) modes. Actually McCulloch's formula completely ignores the mode shape (it ignores not only whether TE or TM but also it ignores the quantum mode shape numbers m,n,p). This is a weakness in McCulloch's formula (not present in Notsosureofit's formula that does take into account the mode shapes).
Those claiming much larger thrust and thrust/InputPower claim to use TE modes: Shawyer and Yang.
NASA also reported much larger thrust/InputPower when using TE modes but could not excite it consistently so they switched to TM modes.
So, there is considerable uncertainty when predicting thrust with a formula that ignores the mode shape of EM Drive operation.
The derivation (F = 6PQL/c * [1/(L+4wb) - 1/(L+4ws) ] which I found on http://physicsfromtheedge.blogspot.co.uk/2015/02/mihsc-vs-emdrive-data-3d.html) that I'm using in my spreadsheet doesn't take into account the input frequency of the radiation either, just the Power and the "Q".
EDIT: If I get a chance tonight I'll try to add Notsosureofit's formula to my spreadsheet and see what happens
Of course there are many ways to look at this, to play devil's advocate:
1) It may be that Shawyer's and Yang's claims are unreliable and the only reliable claims are those of NASA using TM modes
2) Since so little is known with certainty at this point in time, the simplicity of McCulloch's formula at this stage may be justified, as there is no point in overfitting unreliable data. -
#213 by phaseshift on 10 Aug, 2015 16:37
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Interesting Russian EMDrive like patent:
http://bankpatentov.ru/node/123593
and comment received on Reddit EMDrive forum:
https://www.reddit.com/r/EmDrive/comments/3ceyjv/email_from_roger_shawyer/ctww6rd
As Dr. Vladimir Leonov claims the "Shawyer Effect" works via the QV, Dr. White might be interested.
Thanks for posting this TT. Warping space is a requirement of the EM-Drive and as the author states it can be done through an EM interaction. -
#214 by Rodal on 10 Aug, 2015 17:53
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Off topic alert - Today, I turned the big six-zero; a milestone birthday. Which should be used to convince others that one can still think, dream and build well into their senior era. So many companies and institutions look to replace older folks once they turn 50...I know from experience. I also know that its a waste of talent to do this.
So, here's to the older generation still plugging away at science. How I wish something like this project were around when I was much younger. THAT should be a message to the young folks out there to get involved in science early. Push the envelope, think outside the box, do something different...who knows, what you may come up with could change the world.
Onward and upward - Dave (rfmwguy)
Just think of it, Dave: Donald Trump is over 69 years old, so you have more than 9 years left for you to run for President of the US
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#215 by RotoSequence on 10 Aug, 2015 18:03
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Just think of it, Dave: Donald Trump is over 69 years old, so you have more than 9 years left for you to run for President of the US
13 years if you wait as long as Bernie Sanders did.
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#216 by SeeShells on 10 Aug, 2015 18:11
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https://drive.google.com/folderview?id=0B1XizxEfB23tfmVCZlhnNUVtTGRoTTlZSGJiT3ZfSHBvYnNELUc1WlN0Sk15ZDZud3pSWmM&usp=sharing
I took both Center x and Center Y pages and opened them into separate folders, sized them so one row was 14 images across and the vertical columns were synced 00, 01, 02, 03, 04... same time slice. Then switched back and forth between the pages comparing a image and mode for X to Y and at the same position.
In some cases the modes match X and Y but several they don't even come close. Just another flag of an interesting anomaly of how you could see in a relatively symmetrical cavity mode variation just between a X slice through the middle and a Y slice through the middle in the same time stamp.
Or has everyone seen this weirdness and you're going to go... phhhsst, silly old woman...
Shell -
#217 by Rodal on 10 Aug, 2015 18:30
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https://drive.google.com/folderview?id=0B1XizxEfB23tfmVCZlhnNUVtTGRoTTlZSGJiT3ZfSHBvYnNELUc1WlN0Sk15ZDZud3pSWmM&usp=sharing
Since the mode shapes are shown on different scales, without showing the numbers, a mode shape that has magnitude that is dozens or hundreds of times smaller amplitude (and thus insignficant) looks significant when compared without numbers. Hence the images are very difficult to understand .
I took both Center x and Center Y pages and opened them into separate folders, sized them so one row was 14 images across and the vertical columns were synced 00, 01, 02, 03, 04... same time slice. Then switched back and forth between the pages comparing a image and mode for X to Y and at the same position.
In some cases the modes match X and Y but several they don't even come close. Just another flag of an interesting anomaly of how you could see in a relatively symmetrical cavity mode variation just between a X slice through the middle and a Y slice through the middle in the same time stamp.
Or has everyone seen this weirdness and you're going to go... phhhsst, silly old woman...
Shell
Remember how we progressed:
1) At the beginning of MEEP runs, the same fields were shown on different scales from time step to time step. It looked so crazy that even the field outside the EM Drive had flashing colors. And inside the EM Drive we could see fractals that were numerical artifacts.
This was fixed by showing all the time steps at the same final scale. This fixed the fractals and the crazy colors outside the EM Drive.
2) We still have the problem that different fields in different directions: Ex, Ey, Ez, Hx, Hy, and Hz, are shown with different scales. Thus one is not able to distinguish, say if E in the x direction is 1000 times less than E in the y direction. Thus we cannot distinguish "noise" from signal.
ALL electric fields should be shown on the same scale and all magnetic fields should be shown to the same scale. Otherwise there is no comprehension.
3) I cannot tell what the mode shape being excited is, from looking at these images: is it TE ? is it TM? nobody knows. Why is it that nobody knows? Because the fields are not shown to the same scale, thus nobody can tell whether it is TE or TM. We don't know what is noise and what is signal.
Is the field in the longitudinal z direction an electric field (and hence a TM mode) or is it a magnetic field (and thus a TE mode). We cannot tell, both mode shapes are being shown and we don't know which is large and which is negligible.
If they would be shown to the same scale, and one mode shape happens to be 100 times smaller magnitude than another one, it would look like zero, and we would not look at it, thus we would better understand because we would be looking ONLY at the mode shapes that are high in magnitude. The way it is now, we don't know what is high magnitude and what is low magnitude.
Imagine what life would be like if your senses would be such that we would not be able to distinguish between what is near and what is far, between what is high and what is low, we would be lost.
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#218 by X_RaY on 10 Aug, 2015 18:53
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Happy birthday rfmwguy
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#219 by rfmwguy on 10 Aug, 2015 19:11
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Happy birthday rfmwguy
Danke, herr x_ray!
was perfect. Funny how people jump to extreme applications without due-diligence on prototypes...i.e. replication, explanation and 3rd party verification. That leads to speculation on whether its all a funding scheme. 