If there is a moveable small end, then I can't guess what the interior of the cylinder looks like.
For the O.D. of the copper straight section I get 18.8 cm if that helps (using the pot as ref)15.3 cm using the RF connector, but not sure of the right connector and worse camera angle, sooo ?
Quote from: Notsosureofit on 10/17/2014 08:11 pmFor the O.D. of the copper straight section I get 18.8 cm if that helps (using the pot as ref)15.3 cm using the RF connector, but not sure of the right connector and worse camera angle, sooo ?I offer to try my hand at dimensional analysis. What is being used as the basis for the dimensional extrapolations you guys have come up with?I would start with the nut diameter. These are likely to be standard, and unlikely to be guessed at wrongly by a factor of two.
Quote from: frobnicat on 10/17/2014 05:54 pm...Waiting for adjusted inputs...We still would like to hear whether there is an argument that can be made, explaining the formulas that model the experimental results either as:A) an experimental artifactB) a photon rocketYou can use the whole data (including the outlier) if you like to make the argument. For the photon rocket argument I don't understand how the photons get out of the EM Drive and how does it get to do better than a perfect photon rocket.Can you make an experimental artifact argument?
...Waiting for adjusted inputs...
Quote from: Rodal on 10/17/2014 06:13 pmQuote from: frobnicat on 10/17/2014 05:54 pm...Waiting for adjusted inputs...We still would like to hear whether there is an argument that can be made, explaining the formulas that model the experimental results either as:A) an experimental artifactB) a photon rocketYou can use the whole data (including the outlier) if you like to make the argument. For the photon rocket argument I don't understand how the photons get out of the EM Drive and how does it get to do better than a perfect photon rocket.Can you make an experimental artifact argument?Me ? Not really.Right now my bet would be something in the line of induced DC component interacting magnetically with either earth magnetic field and/or local field (damping system) and/or local ferromagnetic chamber walls. Those are words so this is not an argument yet. Please don't argue, yet.But if anyone wants to help me putting up this argument (and then argue) :for this argument I would need to know if there is a possibility of non linearities around 0 of conductivity in skin of cavity for strong RF fields. Even one part per thousand could be interesting. A small asymmetry in hysteresis for instance. Asking Mulletron and a few search of the available literature didn't float anything like that, at least for metal conductors (rather into semiconductors with more or less exotic composition, not plain copper). Or for dielectrics but I guess they don't have DC conduction to speak of. I don't know if it is because there is no such effect at all in conductors, or because this effect is generally ignored, or because it would be a complex special case of dielectric (non linear) very close conductor (eddy currents). How tight the dielectrics are encased in copper ? Also I would need to understand the geometry of eddy currents, and my EM course is long ago and wasn't specifically on microwave cavities or skin effects. So I'm a bit disarmed.Can we do summary, for the seven data points, of qualitative boolean or discrete values like1/ vacuum ?2/ magnetic damping ?3/ ferromagnetic walls nearby (vacuum chamber or else) ?4/ offboard generator ?5/ inverted pendulum or torsion balance ?6/ thermal isolation casing ?7/ ... ?at least for all such boolean or discrete values for which we have values or likely guess for most of the data points ?Could we also throw in the negative results while we are at it : Brady without dielectric, Brito/Marini/Galian without magnetic damping, what else ?Maybe we could then see some patterns, some already discussed, maybe some others ...
The upper gizmo is the motor and at the bottom it's driving a variable resistor as position feedback. It probably was fed w/ a fixed frequency generator.Hanging out the back is prob a limit switch.
....Right now my bet would be something in the line of induced DC component interacting magnetically with either earth magnetic field ...
Quote from: Notsosureofit on 10/17/2014 07:53 pmThe upper gizmo is the motor and at the bottom it's driving a variable resistor as position feedback. It probably was fed w/ a fixed frequency generator.Hanging out the back is prob a limit switch.Shawyer's demonstrator : isn't it possible that it's a thread driving a plate in longitudinal position inside the cylinder, that is an adjustable length cavity ? Is that what you mean by "fed with a fixed frequency" : the cavity is adjusted to fit the frequency and not the inverse ? Isn't all that documented by Shawyer ? Or is it in NDA ?
Eliminate 5/ inverted pendulum or torsion balance ?I did a fully coupled nonlinear analysis and the problem cannot be explained solely on that basis.What it can do is to magnify another effect.
Concerning: <<Could we also throw in the negative results while we are at it : Brady without dielectric>>No, that is not a relevant result, did you have a chance to look at my posts regarding that? Conducted first in the their testing program, at a completely different frequency, way off the scale to the right on their S22 chart and their COMSOL Finite Element predictions. I don't think it has anything to do with the dielectric. At that frequency they didn't report any force measurements whatsoever (with or without). Basically they were flying blind, they did that experiment at a different frequency, they did not report any Q at that frequency, and from the S22 plot it is likely there was no resonance at that frequency
Concerning <<Brito/Marini/Galian>>Not relevant to microwave cavities. Not relevant to Shawyer, China or NASA Eagleworks experiments. Only relevant to Woodward/March MET.
Concerning <<6/ thermal isolation casing ?>>What is that? Please elaborate
Quote from: frobnicat on 10/17/2014 10:12 pm....Right now my bet would be something in the line of induced DC component interacting magnetically with either earth magnetic field ...Interaction with the Earth's magnetic field is also first in my list of experimental artifacts. Why would an interaction with the Earths' magnetic field be oriented along the cone axis and would favor a larger difference between the diameters of the bases of the truncated cone?
Quote from: Rodal on 10/17/2014 10:39 pmQuote from: frobnicat on 10/17/2014 10:12 pm....Right now my bet would be something in the line of induced DC component interacting magnetically with either earth magnetic field ...Interaction with the Earth's magnetic field is also first in my list of experimental artifacts. Why would an interaction with the Earths' magnetic field be oriented along the cone axis and would favor a larger difference between the diameters of the bases of the truncated cone?Good questions.Can earth magnetic field account for the order of magnitude of results ? This I could help to address with rough estimates. The direction, axis and magnitude dependence on geometry, I have no precise idea right now and am unsure I could contribute. Thinking about it (part time).
Quote from: frobnicat on 10/17/2014 11:22 pmQuote from: Rodal on 10/17/2014 10:39 pmQuote from: frobnicat on 10/17/2014 10:12 pm....Right now my bet would be something in the line of induced DC component interacting magnetically with either earth magnetic field ...Interaction with the Earth's magnetic field is also first in my list of experimental artifacts. Why would an interaction with the Earths' magnetic field be oriented along the cone axis and would favor a larger difference between the diameters of the bases of the truncated cone?Good questions.Can earth magnetic field account for the order of magnitude of results ? This I could help to address with rough estimates. The direction, axis and magnitude dependence on geometry, I have no precise idea right now and am unsure I could contribute. Thinking about it (part time).I'm not too concerned with the order of magnitude at this point in time because the inverted torsional pendulum can amplify whatever effect is thrusting the device (maybe even dark matter ). I would think that the main thing to do is to find a classical experimental artifact that also acts along the axis of the cone, that depends on orientation of the big base and that it is larger with increasing difference between the base diameters.
There are no details in the literature as to the precise dimensions of the cavities used in the experiments, so that an example roughly similar to the overall dimension reported and with the proportions observed in the published photographs will be used. Assuming a wall of thickness 1 mm, and a copper mass density of 8.9×103 kg/m3, we have σ = 8.9kg/m2. We further consider the copper cavity to have r1 = 18 cm, r2 = 36 cm, and θ0 = 22◦. For this cavity, the lowest TM mode corresponds to the order n = 5.75632 of the Legendre polynomial, with a resonant frequency ν = 1.05GHz. For a resistivity η = 1.72×10−8 Ωm the quality factor for this mode is Qcav = 3.13×104. The next two TM modes have the same order n = 5.75632, and resonant frequencies ν = 2.05GHz11 and ν = 2.76GHz, with quality factors Qcav = 3.11 × 104 and Qcav = 5.24 × 104, respectively.