Quote from: SeeShells on 07/09/2015 01:43 pmQuote from: TheTraveller on 07/09/2015 05:20 amFurther info on the antenna arrangement I'll be using on my 2.45GHz version of the Flight Thruster.As the EM waves in a cavity with spherical end plates are spherical, the antenna also needs to be spherical as per the sidewall insertion point curve of the EM wave at that point.I could have used a single stub 1/4 wave antenna curved to match the spherical EM wave shape but I had reservations that the end point of a single 1/4 wave stub inside the cavity may shift over time.To stop any shifting, especially as I plan to ship finished EMDrives all over the planet, the single 1/4 wave stub antenna was replaced by 3 x 1/4 wave stub antennas that are joined at the centre and attached to the centre of 3 Rf connectors fitted into the side walls.Trust the attached crude drawing makes it clear how I intend to excite TE013 mode and do so in a way to introduce min phase distortion into the internal resonant standing wave by the excitation antenna.I would hope you take in consideration the phases of your antennas and the distance from each other, you wouldn't want them to cause standing wave attenuations with each other canceling out a good idea.Shell, there is also the issue that in the drawing, the assumption is made that the wave-patterns in the longitudinal direction are sinusoidal harmonic with equidistant nodal points. This is true for a cylindrical waveguide but it is not true for a conical waveguide. With a conical waveguide the wave-patterns in the longitudinal direction are not sinusoidal harmonic: the nodes are not equidistant. How different from equidistant the nodes are depends on the mode(s) being excited and their participation. Hopefully by placing the antenna where it is proposed he can force that mode, but a lot depends on nearby modes and mode participation. Since he is not using a magnetron, that may help in eliminating other modes from participating.
Quote from: TheTraveller on 07/09/2015 05:20 amFurther info on the antenna arrangement I'll be using on my 2.45GHz version of the Flight Thruster.As the EM waves in a cavity with spherical end plates are spherical, the antenna also needs to be spherical as per the sidewall insertion point curve of the EM wave at that point.I could have used a single stub 1/4 wave antenna curved to match the spherical EM wave shape but I had reservations that the end point of a single 1/4 wave stub inside the cavity may shift over time.To stop any shifting, especially as I plan to ship finished EMDrives all over the planet, the single 1/4 wave stub antenna was replaced by 3 x 1/4 wave stub antennas that are joined at the centre and attached to the centre of 3 Rf connectors fitted into the side walls.Trust the attached crude drawing makes it clear how I intend to excite TE013 mode and do so in a way to introduce min phase distortion into the internal resonant standing wave by the excitation antenna.I would hope you take in consideration the phases of your antennas and the distance from each other, you wouldn't want them to cause standing wave attenuations with each other canceling out a good idea.
Further info on the antenna arrangement I'll be using on my 2.45GHz version of the Flight Thruster.As the EM waves in a cavity with spherical end plates are spherical, the antenna also needs to be spherical as per the sidewall insertion point curve of the EM wave at that point.I could have used a single stub 1/4 wave antenna curved to match the spherical EM wave shape but I had reservations that the end point of a single 1/4 wave stub inside the cavity may shift over time.To stop any shifting, especially as I plan to ship finished EMDrives all over the planet, the single 1/4 wave stub antenna was replaced by 3 x 1/4 wave stub antennas that are joined at the centre and attached to the centre of 3 Rf connectors fitted into the side walls.Trust the attached crude drawing makes it clear how I intend to excite TE013 mode and do so in a way to introduce min phase distortion into the internal resonant standing wave by the excitation antenna.
I really thought Pinheiro's "self accelerating engine" would have stirred the pot more than it did. Folks are up in arms about how EmDrive violates Conservation of Momentum and Newton's Third Law.This paper really made me go hmmmmm.On Newton's third law and its symmetry-breaking effectsMario J Pinheirohttp://iopscience.iop.org/1402-4896/84/5/055004http://arxiv.org/pdf/1104.5011.pdf (see page 12, pg 18 fig 2)@Rodal did a fantastic thermal analysis early on. So we're already smart on this.http://www.researchgate.net/publication/268804028_NASA%27S_MICROWAVE_PROPELLANT-LESS_THRUSTER_ANOMALOUS_RESULTS_CONSIDERATION_OF_A_THERMO-MECHANICAL_EFFECTSo did one end stay hotter than the other while turned on? I bet TE012 would generate tons of heat at the small end (strong magnetic field there). Actual thermal data would be awesome right about now. My dinky amp doesn't generate any noticeable heat and it can't excite TE01X anyway. We miss having you here @Star Drive. I bet you already know all about this. I did manage to dig up his thermal analysis from here:http://forum.nasaspaceflight.com/index.php?topic=36313.msg1326997#msg1326997and is attached. This looks like it was TM212 @ 1946.65 MHz.Why am I looking into https://en.wikipedia.org/wiki/Non-equilibrium_thermodynamics ?It is clear to me that the "momentum from the QV fluctuations" mechanism (if it is even really happening) isn't the dominant mechanism here. For cavities sans dielectrics, this is especially apparent. Shawyer et al report thrust from unloaded cavities (Eagleworks did not).There must be another...or more than one "thrust mechanism" happening simultaneously here. Gotta go back through the threads and locate which modes @Star Drive said caused the frustum to thrust large end forward to see if there are any patterns. I remember at least one instance where he reported the dielectric fastener popped loose and the thrust reversed too.Been taking a break on the research and enjoying the summer (really don't want to get burned out here). Turns out there are other things in life besides EmDrive. Enjoying the family time. Will jump back in full swing with the experiment soon.
I really thought Pinheiro's "self accelerating engine" would have stirred the pot more than it did. Folks are up in arms about how EmDrive violates Conservation of Momentum and Newton's Third Law.This paper really made me go hmmmmm.On Newton's third law and its symmetry-breaking effectsMario J Pinheirohttp://iopscience.iop.org/1402-4896/84/5/055004http://arxiv.org/pdf/1104.5011.pdf (see page 12, pg 18 fig 2)...
A very important difference between a gas of massive particles and a photon gas with a black body distribution is that the number of photons in the system is not conserved. A photon may collide with an electron in the wall, exciting it to a higher energy state, removing a photon from the photon gas. This electron may drop back to its lower level in a series of steps, each one of which releases an individual photon back into the photon gas. Although the sum of the energies of the emitted photons are the same as the absorbed photon, the number of emitted photons will vary. It can be shown that, as a result of this lack of constraint on the number of photons in the system, the chemical potential of the photons must be zero for black body radiation.
I really thought Pinheiro's "self accelerating engine" would have stirred the pot more than it did. Folks are up in arms about how EmDrive violates Conservation of Momentum and Newton's Third Law.This paper really made me go hmmmmm.On Newton's third law and its symmetry-breaking effectsMario J Pinheirohttp://iopscience.iop.org/1402-4896/84/5/055004http://arxiv.org/pdf/1104.5011.pdf (see page 12, pg 18 fig 2)
I really thought Pinheiro's "self accelerating engine" would have stirred the pot more than it did. Folks are up in arms about how EmDrive violates Conservation of Momentum and Newton's Third Law.Been taking a break on the research and enjoying the summer (really don't want to get burned out here). Turns out there are other things in life besides EmDrive. Enjoying the family time. Will jump back in full swing with the experiment soon.
The cavity is reservatory of energy, like a LC circuit. If a mode has been excited by the source is natural the growing of amplitude of the fields because of the succesives reflections of the counter propagating traveling waves ( forming the stationary wave) will summ with waves generated by the source. This grow will happens until the loss in the walls of the cavity becomes equal the power generated by the source.
Advanced data analysis - For DIYers, I'd recommend we consider standardizing on some DAC software. I've written a couple of LabView projects which are basically a clean slate in displaying test data. (have no biz relationship with National Instruments BTW, just good results).http://www.ni.com/labview/There are student discounts and a free trial period. Chart recordings, temperatures, displacement, vibration, acceleration, voltages, currents, etc are all possible with external sensors. I have this in the back of my mind if I see positive results from the fulcrum test.Word of note, shielding of all sensor interconnects will be critical and I wouldn't start off with this initially. Non-digital measurement is less risky of false positives, but those planning on more elaborating testing down the road should consider LabView as an easy to use GUI based test platform.http://sine.ni.com/cms/images/casestudies/bmpc.bmp?size
...So far, I'm still of the opinion that (the Turtle is correct) it's the resonant standing wave condition that supplies the force through a General Relativistic rotation in the time-z plane.Edit: I should add that finding the 90 degree phase shift component in that rotation is essential to this argument.
Quote from: Rodal on 07/09/2015 01:52 pmQuote from: SeeShells on 07/09/2015 01:43 pmQuote from: TheTraveller on 07/09/2015 05:20 amFurther info on the antenna arrangement I'll be using on my 2.45GHz version of the Flight Thruster.As the EM waves in a cavity with spherical end plates are spherical, the antenna also needs to be spherical as per the sidewall insertion point curve of the EM wave at that point.I could have used a single stub 1/4 wave antenna curved to match the spherical EM wave shape but I had reservations that the end point of a single 1/4 wave stub inside the cavity may shift over time.To stop any shifting, especially as I plan to ship finished EMDrives all over the planet, the single 1/4 wave stub antenna was replaced by 3 x 1/4 wave stub antennas that are joined at the centre and attached to the centre of 3 Rf connectors fitted into the side walls.Trust the attached crude drawing makes it clear how I intend to excite TE013 mode and do so in a way to introduce min phase distortion into the internal resonant standing wave by the excitation antenna.I would hope you take in consideration the phases of your antennas and the distance from each other, you wouldn't want them to cause standing wave attenuations with each other canceling out a good idea.Shell, there is also the issue that in the drawing, the assumption is made that the wave-patterns in the longitudinal direction are sinusoidal harmonic with equidistant nodal points. This is true for a cylindrical waveguide but it is not true for a conical waveguide. With a conical waveguide the wave-patterns in the longitudinal direction are not sinusoidal harmonic: the nodes are not equidistant. How different from equidistant the nodes are depends on the mode(s) being excited and their participation. Hopefully by placing the antenna where it is proposed he can force that mode, but a lot depends on nearby modes and mode participation. Since he is not using a magnetron, that may help in eliminating other modes from participating.I'm quite aware the nodes are not equidistant as the guide wavelength varies as the tapered waveguide diameter varies along the tapered waveguide.My calculator figures out where the 1/4 wave position is from the big end, factoring in the continually variable guide wavelength and the radius of curvature of the spherical wave at that point.There are no nearby TE modes and my antenna will not excite TM modes.
Quote from: rfmwguy on 07/09/2015 02:50 pmAdvanced data analysis - For DIYers, I'd recommend we consider standardizing on some DAC software. I've written a couple of LabView projects which are basically a clean slate in displaying test data. (have no biz relationship with National Instruments BTW, just good results).http://www.ni.com/labview/There are student discounts and a free trial period. Chart recordings, temperatures, displacement, vibration, acceleration, voltages, currents, etc are all possible with external sensors. I have this in the back of my mind if I see positive results from the fulcrum test.Word of note, shielding of all sensor interconnects will be critical and I wouldn't start off with this initially. Non-digital measurement is less risky of false positives, but those planning on more elaborating testing down the road should consider LabView as an easy to use GUI based test platform.http://sine.ni.com/cms/images/casestudies/bmpc.bmp?sizeAlready downloaded. Using it in conjunction with an oscilloscope to check and make sure the signal generator is outputting the correct values. The DAQs are quite expensive, at least for me anyways. So, I'll hold off on data acquisition in that respect. But Free/19.99 for student edition is a lot better than $10,000 for the full program. Edit: once I finish the OpenCV program, I'll post it here in case others want to use this method for data acquisition on a laser. My goal is to be accurate to within a millimeter. Maybe less.
Quote from: Notsosureofit on 07/09/2015 02:27 pm...So far, I'm still of the opinion that (the Turtle is correct) it's the resonant standing wave condition that supplies the force through a General Relativistic rotation in the time-z plane.Edit: I should add that finding the 90 degree phase shift component in that rotation is essential to this argument.Have you taken a look at Todd's (WarpTech's ) latest analysis?His formulation looks (at least superficially) similar to yours. Any comments on a comparison of Notsosureofit and WarpTech's latest would be deeply appreciated, if you have a chance.
Quote from: WarpTech on 07/09/2015 03:44 am...The paradox with propellant driven space craft was explained too, by Dr. White. It occurs anytime "constant acceleration" is assumed, without taking into account the variables in the av(t) expression I posted. In the case of the EM drive where there is no exhaust, dm/dt is replaced by the change in potential energy from the small end, to the big end, per unit time, /c2. And BTW, if the EM drive were to store every bit of energy put into it, with a high power source it would have to explode eventually. The energy either needs to escape, generate heat or move the thing in order to dissipate. Or else the source input will eventually become saturated until nothing more will go in. ToddEach time I try to stay on topic with this breakeven business, which you say I have "wrong", you throw another spanner in the works. Let's try and focus here. I want to understand what's "wrong" as you see it. So far, you're not making sense to me. If you do want to make sense to me, and convince me that I'm "wrong", you're going to have to take my derivation and show, line by line, the "right" substitution.Over to you.
...The paradox with propellant driven space craft was explained too, by Dr. White. It occurs anytime "constant acceleration" is assumed, without taking into account the variables in the av(t) expression I posted. In the case of the EM drive where there is no exhaust, dm/dt is replaced by the change in potential energy from the small end, to the big end, per unit time, /c2. And BTW, if the EM drive were to store every bit of energy put into it, with a high power source it would have to explode eventually. The energy either needs to escape, generate heat or move the thing in order to dissipate. Or else the source input will eventually become saturated until nothing more will go in. Todd
Re frobnicat Post #3681“But you seem to imply in your posts that the risk is more in false negatives (a working principle and experimenters failing to record thrust from it) rather than false positives (a bogus principle and experimenters failing to report null results, down to a certain sensitivity).”You are right. Sorta. What I am saying is that the risk is BOTH.
I really don't like this, to ask. I've always forged my own path through the years with very little help and built businesses in industries where a billion spent is sometimes a drop in the bucket.Totaling up what the costs I'm facing it became clear that with the little I get on retirement I can't do it in the time frame needed. I guess I'm asking for a little help and only if you can.I'm so driven to see real data from these test and to add to the pool of knowledge, I have to swallow my pride and ask. http://www.gofundme.com/yy7yz3kThank you all for your support, your ideas and most of all sharing a dream.Shell
Quote from: Rodal on 07/09/2015 11:55 amQuote from: TheTraveller on 07/09/2015 07:54 amThe Chinese may have figured out how to make a cavity with a Q of 117,500 using flat end plates.As per the attachment they build in a short section, at each end of the tapered wave guide, of constant diameter circular waveguide that allows the spherical waves in the tapered portion of the cavity to transition from/to a planar wave that will generate no phase distortion as it bounces off the flat end plate.Very clever.The drawings also show how they do impedance matching.See attachment.I now know my 100,000 Q goal is obtainable. Yea!If you draw a horizontal axis through the middle of the waveguide in the picture you show, what does the waveguide opening into the cavity on the plane perpendicular to that axis look like?In other words, what does the other view look like?It would be nice if we could guesstimate what the waveguide opening aspect ratio is, compared to the lateral cavity dimensionsMore info is in the paper, which is in Chinese. Attached.I don't think the drawing is dimensionally correct.
Quote from: TheTraveller on 07/09/2015 07:54 amThe Chinese may have figured out how to make a cavity with a Q of 117,500 using flat end plates.As per the attachment they build in a short section, at each end of the tapered wave guide, of constant diameter circular waveguide that allows the spherical waves in the tapered portion of the cavity to transition from/to a planar wave that will generate no phase distortion as it bounces off the flat end plate.Very clever.The drawings also show how they do impedance matching.See attachment.I now know my 100,000 Q goal is obtainable. Yea!If you draw a horizontal axis through the middle of the waveguide in the picture you show, what does the waveguide opening into the cavity on the plane perpendicular to that axis look like?In other words, what does the other view look like?It would be nice if we could guesstimate what the waveguide opening aspect ratio is, compared to the lateral cavity dimensions
The Chinese may have figured out how to make a cavity with a Q of 117,500 using flat end plates.As per the attachment they build in a short section, at each end of the tapered wave guide, of constant diameter circular waveguide that allows the spherical waves in the tapered portion of the cavity to transition from/to a planar wave that will generate no phase distortion as it bounces off the flat end plate.Very clever.The drawings also show how they do impedance matching.See attachment.I now know my 100,000 Q goal is obtainable. Yea!