Author Topic: EM Drive Developments - related to space flight applications - Thread 3  (Read 1875431 times)

Offline WarpTech

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...

This Russian website has this book on

Theory of Photon Acceleration
J T Mendonca
http://bit.ly/1M9gPyy

by one of the original discoverers of what is known as photon acceleration.

This website version of the book is only shown here for research purposes, for researchers such as @Notsosureofit, conducting such research.

People are warned that this book is copyrighted and published by The Institute of Physics, and if interested, you are advised to purchase the book from an authorized bookseller, for example here is Amazon

http://amzn.to/1FxkrXd

instead of relying on the copy from the Russian website.
...

This book is a goldmine! Thank you.

Offline dustinthewind

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I was thinking about the issue of neutralizing force from expanding gas in the cavity when it is heated.  I was thinking we might put 2 nozzles on the sides.  The idea being to place them at a set height so that the volume of air that leaves below is equal to the volume of air the leaves above.  (Edit: The idea being to eliminate pressure gradients inside the cavity.  The extreme being we place the nozzles at the far end.  See link: http://forum.nasaspaceflight.com/index.php?topic=37642.msg1385537#msg1385537 )  I attached a diagram with problem worked out.  The height to place the nozzles if my assumption is correct is height = hv1 .

I was thinking to neutralize the force from convection of air also.  I think some one else already mentioned this but what about just putting the device in a box.  Then the force of air pushed by heat from the cavity strikes the box and there should be cancellation. 

measuring the temperature in the box and cavity we can calculate the buoyancy of the air to boot.  That or just flip the thing over and take another measurement. 

My only worries is that the side tubes for gas ejection might change the behavior of the currents in the cavity. 

I tested the equations for the resulting height by substituting it into the volume equations and I get equal volumes for V1 and V2. 
« Last Edit: 06/07/2015 01:51 AM by dustinthewind »

Offline deltaMass

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I see no point in equalising volumes like that. All that's necessary is the venting orthogonal to the thrust (you have that) and two nozzles, diametrically opposite one another (you have that too). I don't think the height placement is critical.

(I checked your maths and it's correct btw)
« Last Edit: 06/05/2015 08:11 AM by deltaMass »

Online RotoSequence

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I'm sure most have seen this but it's great to visualize a pulse of photons traveling down a coke bottle. What I found interesting is when the pulse reaches the top of the bottle and the area that shrinks in dimension. The wave front traveling in the center remains at the same speed  but look at the sidewall of the bottle shaped like the frustum the wave is still the same but the distance traveled on the surface of the sidewall is longer. Just found this an interesting visual.

Where do those flashes of light behind the advancing wave come from? They seem to appear (popping into existence, even) behind the initial pulse every time the lengthwise volume of the bottle stops shrinking (5:17 to 5:21, 5:25 to 5:29). What's more, why do those flashes look like they're stationary?

EDIT: Is the light wave compensating for the change in geometry by making a portion of the light orthogonal to the original direction of the collimated beam? Does the delay come from time of flight to the camera?
« Last Edit: 06/05/2015 09:35 AM by RotoSequence »

Offline Davinator

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Be careful to stick to space flight elements. This is a space flight site and not a physics site...... or a poetry site.  Yes, there was a poem discussed on here, which I've saved if that person wants it back (PM me if you didn't save it), but really no place for it on here. Small trim.

Offline Giovanni DS

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I can agree about poetry and any other off topic but Physics, Math and Space Flight are closely related IMHO. Everything is finalized to flyable thrusters, is there the need to mention that in each single post?
« Last Edit: 06/05/2015 09:37 AM by Giovanni DS »

Offline OttO

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I do not remember if the following paper has been dissected before.

Generating Net Forces from Backgrounds of Randomly Created Waves
http://file.scirp.org/Html/3-7501960_50603.htm

"We have shown that in a background of randomly created waves a structure with a rectangular concave interior embodying parallel reflecting plates can be subject to net forces.....
For the electromagnetic waves associated with the quantum vacuum, the energy extracted can be seen as originating from the curvature of space- time, which then would become less curved locally. In this perspective, an extended principle of conservation of energy-momentum could be applied to a delimited region of space-time"


It is the reverse I thought and seems shaky as hell...


EDIT: OK after research, I think he is a fraud...
« Last Edit: 06/05/2015 11:42 AM by OttO »

Offline SeeShells

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holes vs not

Nice info. Is a keeper.

My issue would be getting a smooth & accurate roll of the frustum side walls if using other than a solid sheet. Not saying it can't be done but maybe not KISS.
Who said I'm going to do this one in a smooth and slick way? ;) You're right it is tough to take a perforated sheet and get it smooth. This one is my test bed, trying from the get go my different ideas, so it's not going to be a nice smooth curve. It's like when you and Rodal were tap dancing together today (and were doing a beautiful job BTW) a design factor becomes so close to zero why bother. This is going to be a little bent. I'm going to use a hexagonal funnel shape.

Offline SeeShells

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This is for those of you who believe the refractive index of the vacuum is simply a "scalar field". It is not, it is a tensor field and behaves like an anisotropic crystal.

https://www.researchgate.net/publication/1968721_Effective_refractive_index_tensor_for_weak_field_gravity

Effective refractive index tensor for weak-field gravity
Petarpa Boonserm †, Celine Cattoen ‡, Tristan Faber §, Matt Visser ∥, and Silke Weinfurtner ¶
School of Mathematics, Statistics, and Computer Science, Victoria University of Wellington,
P.O.Box 600, Wellington, New Zealand

Abstract.

Gravitational lensing in a weak but otherwise arbitrary gravitational field can be described in terms of a 3 × 3 tensor, the “effective refractive index”. If the sources generating the gravitational field all have small internal fluxes, stresses, and pressures, then this tensor is automatically isotropic and the “effective refractive index” is simply a scalar that can be determined in terms of a classic result involving the Newtonian gravitational potential. In contrast if anisotropic stresses are ever important then the gravitational field acts similarly to an anisotropic crystal. We derive simple formulae for the refractive index tensor, and indicate some situations in which this will be important.

gr-qc/0411034; 8 November 2004;
Revised 10 March 2005; LATEX-ed 7 February 2008

Enjoy!
Good find
http://edafologia.ugr.es/optmine/intro/doblerew.htm

Offline rfmwguy

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Driven mainly by the $4k cost of a 100W 3.85GHz Rf amp, versus $2k for a 100W 2.45GHz Rf amp and the help Roger Shawyer has provided in getting my EMDrive Calculator operational, I have decided to adopt the EW/Mulletron/Iulian copper frustum design but with a slightly altered length to get TE013 resonance at 2.45GHz.

Will shortly provide data on the TE012 & TE013 resonance frequencies of the EW frustum (calculated as per Shawyer) plus what needs to be changed to achieve resonance at Shawyer's suggested TE013.

As EWs has a variable narrow band Rf generator, would be interesting to see what they get exciting their frustum in TE013 mode at the frequency Shawyer claims will generate resonance. They may need to modify their antenna design and feedin point on the side wall.

Broken record: Careful of the 4KV bias voltage  :P

Not using a magnetron. Instead using a variable frequently narrow band Rf gen with a 100W Rf amp. Similar setup to EW.

Very good! Solid state all the way. Depending on the sig gen, if "thrust" were measured, varying ctr freq would be interesting as well as amplitude and modulation; FM/AM/Phase or perhaps pulsing. This type of setup allows for nice variables for eval. A bit envious here  ;)

p.s. 100 mW 2.4 GHz exciter board shipped and should be here this week for my project...only 8 ctr freqs available  >:(
« Last Edit: 06/05/2015 01:04 PM by rfmwguy »

Offline PaulF

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[youtube]snSIRJ2brEk[/youtube]
I'm sure most have seen this but it's great to visualize a pulse of photons traveling down a coke bottle. What I found interesting is when the pulse reaches the top of the bottle and the area that shrinks in dimension. The wave front traveling in the center remains at the same speed  but look at the sidewall of the bottle shaped like the frustum the wave is still the same but the distance traveled on the surface of the sidewall is longer. Just found this an interesting visual.

Where do those flashes of light behind the advancing wave come from? They seem to appear (popping into existence, even) behind the initial pulse every time the lengthwise volume of the bottle stops shrinking (5:17 to 5:21, 5:25 to 5:29). What's more, why do those flashes look like they're stationary?

EDIT: Is the light wave compensating for the change in geometry by making a portion of the light orthogonal to the original direction of the collimated beam? Does the delay come from time of flight to the camera?

Cherenkov radiation perhaps?

Offline SeeShells

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I'm sure most have seen this but it's great to visualize a pulse of photons traveling down a coke bottle. What I found interesting is when the pulse reaches the top of the bottle and the area that shrinks in dimension. The wave front traveling in the center remains at the same speed  but look at the sidewall of the bottle shaped like the frustum the wave is still the same but the distance traveled on the surface of the sidewall is longer. Just found this an interesting visual.

Where do those flashes of light behind the advancing wave come from? They seem to appear (popping into existence, even) behind the initial pulse every time the lengthwise volume of the bottle stops shrinking (5:17 to 5:21, 5:25 to 5:29). What's more, why do those flashes look like they're stationary?

EDIT: Is the light wave compensating for the change in geometry by making a portion of the light orthogonal to the original direction of the collimated beam? Does the delay come from time of flight to the camera?
BINGO! That's what intrigues me! The beam has not quite hit the end of the cap and here is all this beautiful action in the frustum area of the bottle right after the pulse has passed. I don't think there is a delay to the camera causing it.
What is interesting as well is the wave at the junction of the frustum angle, it's traveling along the boundary of the angle like a wave on the sea shore, appearing to travel faster on the edge or is this just an optical illusion?

Offline Left Field

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[youtube]snSIRJ2brEk[/youtube]
I'm sure most have seen this but it's great to visualize a pulse of photons traveling down a coke bottle. What I found interesting is when the pulse reaches the top of the bottle and the area that shrinks in dimension. The wave front traveling in the center remains at the same speed  but look at the sidewall of the bottle shaped like the frustum the wave is still the same but the distance traveled on the surface of the sidewall is longer. Just found this an interesting visual.

Where do those flashes of light behind the advancing wave come from? They seem to appear (popping into existence, even) behind the initial pulse every time the lengthwise volume of the bottle stops shrinking (5:17 to 5:21, 5:25 to 5:29). What's more, why do those flashes look like they're stationary?

EDIT: Is the light wave compensating for the change in geometry by making a portion of the light orthogonal to the original direction of the collimated beam? Does the delay come from time of flight to the camera?

Cherenkov radiation perhaps?
If I understand the flashes meant... they are internal reflections. The incident light is traveling at an angle to the axis of the bottle, so the light gets refracted toward the normal by the near side of the bottle and then reflected off the far side of the bottle.

Just look at the apple tomato example to see how the light propagates and hopefully it will become clearer.
« Last Edit: 06/05/2015 02:32 PM by Left Field »

Offline SeeShells

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holes vs not

Nice info. Is a keeper.

My issue would be getting a smooth & accurate roll of the frustum side walls if using other than a solid sheet. Not saying it can't be done but maybe not KISS.
Who said I'm going to do this one in a smooth and slick way? ;) You're right it is tough to take a perforated sheet and get it smooth. This one is my test bed, trying from the get go my different ideas, so it's not going to be a nice smooth curve. It's like when you and Rodal were tap dancing together today (and were doing a beautiful job BTW) a design factor becomes so close to zero why bother. This is going to be a little bent. I'm going to use a hexagonal funnel shape.
Started to do the layouts, have the stepper motor lead screw and carrier, drivers and controller, now getting ready to have the endplates water jet cut

Offline deltaMass

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I have an Italian coffee maker that looks like that :-[

Offline zen-in

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holes vs not

Nice info. Is a keeper.

My issue would be getting a smooth & accurate roll of the frustum side walls if using other than a solid sheet. Not saying it can't be done but maybe not KISS.

It's very easy if the Copper is completely soft.   Sheet Copper comes work hardened from the rolling process.  To soften it you have to heat it to a dull red and let it air dry.   That will oxidize the surface.  A sulphuric dip will dissolve all the oxide.   You will have to polish it to get the surface bright again.   If you have a softwood form made to bend the Copper on you can bend the cone by hand; using a rubber hammer for the ends.  For the best RF performance join the seam with a strip of Copper on the outside riveted to both sides; using Copper rivets.

Offline rfmwguy

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[youtube]snSIRJ2brEk[/youtube]
I'm sure most have seen this but it's great to visualize a pulse of photons traveling down a coke bottle. What I found interesting is when the pulse reaches the top of the bottle and the area that shrinks in dimension. The wave front traveling in the center remains at the same speed  but look at the sidewall of the bottle shaped like the frustum the wave is still the same but the distance traveled on the surface of the sidewall is longer. Just found this an interesting visual.

Where do those flashes of light behind the advancing wave come from? They seem to appear (popping into existence, even) behind the initial pulse every time the lengthwise volume of the bottle stops shrinking (5:17 to 5:21, 5:25 to 5:29). What's more, why do those flashes look like they're stationary?

EDIT: Is the light wave compensating for the change in geometry by making a portion of the light orthogonal to the original direction of the collimated beam? Does the delay come from time of flight to the camera?

Cherenkov radiation perhaps?
If I understand the flashes meant... they are internal reflections. The incident light is traveling at an angle to the axis of the bottle, so the light gets refracted toward the normal by the near side of the bottle and then reflected off the far side of the bottle.

Just look at the apple tomato example to see how the light propagates and hopefully it will become clearer.

I think this is a reflection of the packet of photon energy propogating in the frustum-like bottle (towards the large end). A near field effect...comparing this to MW freqs, wonder if the near-field attenuation would be as great? I'm thinking no, as the skin-effect of copper would have far less attenuation at MW than light does in the clear plastic...

Offline hhexo

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I have an Italian coffee maker that looks like that :-[

Me too!
I wonder if one could manufacture an "Espresso EmDrive" that is between Iulian's and the Baby EmDrive in terms of dimensions. :) One could even re-use the hole where the safety valve is as the RF injection hole... And the cylindrical part where the filter is lodged could be used as the range for the variable plate... :D

Who wants to solve the resonance modes analysis for a coffee maker's tank? :P

Edit: I know, I'm joking, but have a look at the rather appropriate shape of the Venus's heating vessel (9):
« Last Edit: 06/05/2015 03:36 PM by hhexo »

Offline SeeShells

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[youtube]snSIRJ2brEk[/youtube]
I'm sure most have seen this but it's great to visualize a pulse of photons traveling down a coke bottle. What I found interesting is when the pulse reaches the top of the bottle and the area that shrinks in dimension. The wave front traveling in the center remains at the same speed  but look at the sidewall of the bottle shaped like the frustum the wave is still the same but the distance traveled on the surface of the sidewall is longer. Just found this an interesting visual.

Where do those flashes of light behind the advancing wave come from? They seem to appear (popping into existence, even) behind the initial pulse every time the lengthwise volume of the bottle stops shrinking (5:17 to 5:21, 5:25 to 5:29). What's more, why do those flashes look like they're stationary?

EDIT: Is the light wave compensating for the change in geometry by making a portion of the light orthogonal to the original direction of the collimated beam? Does the delay come from time of flight to the camera?

Cherenkov radiation perhaps?
If I understand the flashes meant... they are internal reflections. The incident light is traveling at an angle to the axis of the bottle, so the light gets refracted toward the normal by the near side of the bottle and then reflected off the far side of the bottle.

Just look at the apple tomato example to see how the light propagates and hopefully it will become clearer.

I think this is a reflection of the packet of photon energy propogating in the frustum-like bottle (towards the large end). A near field effect...comparing this to MW freqs, wonder if the near-field attenuation would be as great? I'm thinking no, as the skin-effect of copper would have far less attenuation at MW than light does in the clear plastic...
As the packet enters just enters the neck and has passed the frustum area, the frustum area starts to increase dramatically in photonic activity even after the light pulse dissipates into the endcap and in one of the last frames you can see the end result.

Offline Rodal

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...
As the packet enters just enters the neck and has passed the frustum area, the frustum area starts to increase dramatically in photonic activity even after the light pulse dissipates into the endcap and in one of the last frames you can see the end result.
Shell, thanks again for posting this great video and for sharing your great insights.  And thank you for the still photographs !
Your last comment brings to mind something that we have not discussed in enough detail before: the EM Drive shape used by Shawyer for the Demonstrator (and now by Iulian in his next series of tests) is a little like this soda bottle.  The straight section after the taper is like the straight endcap in the soda bottle.

I think that assuming that the Demonstrator behaves like Shawyer's experimental or like NASA's frustum may be  unwarranted because of this straight section after the taper.  It is not a simple truncated cone anymore.  The natural frequencies and mode shapes are different.  The mode shapes are less similar to a cylinder. 
« Last Edit: 06/05/2015 04:14 PM by Rodal »

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