Quote from: Rodal on 02/21/2015 12:56 amQuote from: flux_capacitor on 02/20/2015 11:52 pmQuote from: Flyby on 02/20/2015 11:35 pmFinding pictures of shawyer's test device(s) is not that hard, but can any1 actually confirm that this is the Chinese truncated cone? or is it completely unrelated?...I think it's from Shawyer and improperly attributed to Juan Yang on some other web sites: http://emdrive.com/flightprogramme.htmlSomeone should ask Roger Shawyer directly about the Chinese version (especially the dimensions of the cavity). He knows a lot about it, since he went there to speak with Juan Yang and give her some advice.Yes, that Shawyer's Flight Thruster development programme. A 3.85GHz thruster weighing 2.92 Kg,.http://emdrive.com/flightprogramme.htmlI don't recall estimated dimensions for it. If anybody estimated the dimensions, @aero is the most likely one to have done it.I did not. I see nothing to use as a reference. Perhaps someone could estimate ratios. Big/small, big/height or whatever.
Quote from: flux_capacitor on 02/20/2015 11:52 pmQuote from: Flyby on 02/20/2015 11:35 pmFinding pictures of shawyer's test device(s) is not that hard, but can any1 actually confirm that this is the Chinese truncated cone? or is it completely unrelated?...I think it's from Shawyer and improperly attributed to Juan Yang on some other web sites: http://emdrive.com/flightprogramme.htmlSomeone should ask Roger Shawyer directly about the Chinese version (especially the dimensions of the cavity). He knows a lot about it, since he went there to speak with Juan Yang and give her some advice.Yes, that Shawyer's Flight Thruster development programme. A 3.85GHz thruster weighing 2.92 Kg,.http://emdrive.com/flightprogramme.htmlI don't recall estimated dimensions for it. If anybody estimated the dimensions, @aero is the most likely one to have done it.
Quote from: Flyby on 02/20/2015 11:35 pmFinding pictures of shawyer's test device(s) is not that hard, but can any1 actually confirm that this is the Chinese truncated cone? or is it completely unrelated?...I think it's from Shawyer and improperly attributed to Juan Yang on some other web sites: http://emdrive.com/flightprogramme.htmlSomeone should ask Roger Shawyer directly about the Chinese version (especially the dimensions of the cavity). He knows a lot about it, since he went there to speak with Juan Yang and give her some advice.
Finding pictures of shawyer's test device(s) is not that hard, but can any1 actually confirm that this is the Chinese truncated cone? or is it completely unrelated?...
The photo is a bit blurry and that makes estimating a bit challenging, and there are lens distortions to the photo, but nothing too major. If the concrete block happened to be the standard width of 440 mm, cited by wikipedia, then the dimensions would be roughly as estimated in the chart.I'm an artist, not a physicist. If these dimensions seem wrong and you have a different guess for the width of the concrete block, let me know and I'll recalculate based on your width standard.
Secrets of Antigravity Propulsion Figure 8.4 - copy past this into the Google search. Click the first link it opens up the chapter and the figure 8.4 (interesting picture) Mr. Paul March spoke about. Very interesting reading Mr. Paul, thank you.
A major part of the work is in the development of the frequency tracking algorithm. This is needed to ensure the input frequency matches the resonant frequency of the high Q (60,000) cavity, over the full input power range and the qualification temperature specification.The thruster is designed to be powered from existing flight qualified TWTAs, which are driven from a dual redundant frequency generator unit (FGU) The FGU includes a frequency control loop using feedback signals from the thruster.
According to those figures the frustum height is only 62% of the base diameter. But the height of the frustum in the photo is 75% of its base diameter, and that's excluding the nuts atop the small endplate. If we included those then the percentage would be even greater, closer to 80% of the base diameter. Are we sure those are the correct measures for the frustum in the photo? The distortion in the photo, which is primarily around the periphery, isn't nearly enough to account for that much discrepancy. I don't mind being wrong but I don't see how those numbers jive with the photo.Edit, I see what he's done. He has excluded the height of the base of the frustum and the height of the top of the frustum from the frustum's overall height. If we exclude these in the photo, then the frustum height is almost exactly 62% of the base diameter. So it works out perfectly. (Sorry for the misunderstanding. I'm an artist, not a scientist, lol.)And the diameter of the top cap is 189mm, give or take a mm or two.
Big diameter is 265 mmSmall diameter is 189 mmHeight is 164 mm.
Big diameter is 265 mmSmall diameter is 189 mmHeight is 164 mm.If the diameter of the base and top are measured from where the frustum meets the base and top caps, then Shawyer's numbers (265mm base and 164mm height) don't fit the photo. But if the diameter of the base and top are measured from the widest parts of the end caps, then they fit perfectly with the photo.If you like I'll make another chart to show you what I mean but it'd take twenty minutes or so.
Quote from: JasonAW3 on 02/24/2015 02:16 pm...I take it that this is a hanging Pendulum? ...NASA Eagleworks has not used a hanging pendulum for their measurements.They have used a low thrust torsion pendulum. See the report for further details: http://www.libertariannews.org/wp-content/uploads/2014/07/AnomalousThrustProductionFromanRFTestDevice-BradyEtAl.pdf
...I take it that this is a hanging Pendulum? ...
...And you can see this negative longer term frustum thermal drift by noting the downward going baseline slope of the thrust trace even after the RF power is removed from the copper frustum. ...
Sorry to keep harping on this, I'll soon be done and out of the way. But I just wanna make sure I get this right. Can someone answer the question on the chart?
....Later on thread 2 (related to spaceflight) while explaining why the buckling analysed by Rodal ... would make a ... thrust in opposite direction to the one observed by the pendulum, ...
Quote from: lasoi on 02/25/2015 12:39 amSorry to keep harping on this, I'll soon be done and out of the way. But I just wanna make sure I get this right. Can someone answer the question on the chart?At least for the internal height, the junction between the plates is the place to measure from.The internal diameters need to know the wall thickness of the cone etc.That whole thing looks like he used (standard ?) heavy duty vacuum/pressure components.
An interesting bit of information over on TP, here:http://www.talk-polywell.org/bb/viewtopic.php?f=10&t=5830I would post to the link but for some reason my computer is forbidden to access the arxiv web site. Anyone know why that might be?Anyway, seems that in looking at the Juno fly-by anomaly they have came up with a "new" force relating angular and linear momentum. Seemingly would also work for electrical phenomenon and it might even be of the right order of magnitude to be of interest to us here.
Quote from: frobnicat on 02/25/2015 12:49 am....Later on thread 2 (related to spaceflight) while explaining why the buckling analysed by Rodal ... would make a ... thrust in opposite direction to the one observed by the pendulum, ...That's incorrect.
The buckling analysis (thermal instability) gives a force precisely in the same direction as measured.It was the thermal expansion explanation (advanced by Oak Ridge Labs in another context) that gives a force in the completely opposite direction.Please refer back to the original image to see that the thermal expansion force (of the dielectric, which is what thermally expands the most, as per Oak Ridge) is the one in the wrong direction.The buckling on the end plate is in the opposite direction to the thermal expansion of the dielectric.Buckling movement of the large diameter end is towards the left, and the buckling force is towards the left. (Paul indicates it as "oil canning" of the flat plate).
Now Newton's third law still states that for every action there is an equal and opposite reaction. So when the copper frustum's large OD end-cap's prompt and inward oil canning action, followed by the slower frustum cone thermal expansions, they both push the copper frustum's Center of Mass (CoM) to the left as viewed from the front of the Eagleworks' vacuum chamber looking back at the test article and torque pendulum, while noting how the copper frustum is bolted on to the T.P.. These thermally induced actions to the left requires the torque pendulum's arm to move to the right to maintain the balance of the torque pendulum's arm in the lab's 1.0 gee gravity field, since we also use the Earth's g-field to help null the pendulum's movements.
Thermal expansion of the HD PE dielectric is towards the right.Movement of the EM Drive is towards the left, exactly the same direction as the buckling movement, and the same as the buckling force.
The buckling force is analogous to somebody pushing (actually bending) the center of the end plate towards the left, which will deflect the plate inwards. If the structure (the EM Drive) is free to move, it will move to the left, as a consequence of the plate being pushed inwards towards the left.
The buckling force perfectly explains the initial impulse magnitude, time duration of the impulse, and direction of travel. The buckling force cannot explain the sustained 40 sec force, hence the buckling force explanation is rejected on the grounds that it cannot explain the 40 sec duration of the force.The thermal expansion explanation is rejected, upon inspection, on several grounds that the thermal expansion movement (of the HD PE) is in the opposite direction as the movement of the EM Drive, rejected on the basis that the HD PE has a free surface, hence free to expand, and therefore there should be no force arising from an unrestrained isothermal homogeneous thermal expansion. Thermal stresses arise in restrained materials or those under a temperature gradient or those with anisotropic coefficients of thermal expansion. This follows from the equations of thermoelasticity. The equations presented in the Oak Ridge report do not abide by the equations of thermoelasticity (Boley and Wiener).
Quote from: Rodal on 02/25/2015 01:00 amQuote from: frobnicat on 02/25/2015 12:49 am....Later on thread 2 (related to spaceflight) while explaining why the buckling analysed by Rodal ... would make a ... thrust in opposite direction to the one observed by the pendulum, ...That's incorrect.Maybe, but it appears Paul March in this post says that it is opposite, and I don't see that this disagreement was acknowledged ...
Dr. Rodal analyzed possible thermal instability (thermal buckling of the flat ends) as a cause for the measured thrust and reported this at NSF and at ResearchGate (https://www.researchgate.net/publication/268804028_NASA%27S_MICROWAVE_PROPELLANT-LESS_THRUSTER_ANOMALOUS_RESULTS_CONSIDERATION_OF_A_THERMO-MECHANICAL_EFFECT). A thermo-mechanical effect (thermal buckling) is shown that occurs in less than 1 second (for the copper thickness employed for the microwave cavity), with a temperature increase of a degree C or less and that results in forces of the same magnitude as reportedly measured by NASA. Moreover, this thermal instability produces forces in the same direction as measured, and it will occur in a vacuum (since the heating can be due either to induction heating from the axial magnetic field in a TE mode or resistive heating due to the axial electric field in a TM mode). However, this effect can only explain the initial impulsive force and cannot explain the longer 30 to 40 second measured force. Thus the thrust force measured for up to 40 second is not nullified by this explanation either.Thermal expansion effect as posited by a team from Oak Ridge National Labs for another propellant-less set of experiments was also eliminated as a possible source by the NSF contributors because it would result in forces in the complete opposite direction as the forces measured by NASA.