Quote from: StrongGR on 05/15/2015 02:39 pmThe main result of the paper is that the gravitational effects are proportional to the energy density of the electromagnetic field inside the cavity (roughly speaking). This means that the electromagnetic field inside the cavity determines the way the gravitational field is distributed. A change could be due to the proportionality factor L(x). Of course, there could be an effect due to the Earth gravitational field but I did not estimate it yet.So, if I understand correctly, L(x) is purely a function of the position "x vector" obtained by a defined volume integral, and is only dependent on the geometry of the cavity and the l0 (ell zero) constant which depends on U0 which depends on the source energy.In Equation 37, given a defined geometry of the frustum, "a" is later determined to be a constant term, "b" is also a constant term, so the shape of the function depends on the logarithm and the square of "r vector". However Equation 38 sets a condition by which "r vector" is linear to "z vector". Does this mean that "r vector" is a function of z, i.e. it varies with the position on the height axis of the frustum?Am I understanding it correctly?If that is the case, then the gravitational effect is stronger towards one plate than the other. Which leads to my concerns about a torque being present rather than a thrust. Presumably, in an experiment the frustum is suspended or supported in such a way that a static balance is achieved; however if a torque is present the balance is altered and this could potentially be confused for a thrust depending on how the mechanical parts of the experiment are set up.(I've realised that there could be a torque even in vacuum because you can't remove the existence of the frustum itself, and its weight distribution could change with the gravitational effect)But again, I'm not 100% sure I'm understanding this correctly. I'm just throwing ideas for the smarter people to think about. I hope this is useful.
The main result of the paper is that the gravitational effects are proportional to the energy density of the electromagnetic field inside the cavity (roughly speaking). This means that the electromagnetic field inside the cavity determines the way the gravitational field is distributed. A change could be due to the proportionality factor L(x). Of course, there could be an effect due to the Earth gravitational field but I did not estimate it yet.
Went back to investigate what I reported in post #233 http://forum.nasaspaceflight.com/index.php?topic=36313.msg1318683#msg1318683 about the RF and Microwave Toolbox app. I found that the app is reporting the correct solutions for TE and TM. The help file just had a typo. I verified it against the KWOK lectures http://www.engr.sjsu.edu/rkwok/EE172/Cavity_Resonator.pdf slide 16. KWOK and the APP match. So this works as a quick and easy way to find resonant modes! There really is an app for everything. I remain unconvinced that calculating resonant modes for cylinders is a good approximation for conical frustums though.
Besides, contributions from Earth gravitational field are damped by a factor (Schwarzschild radius)/(Earth radius) where the Schwarzschild radius of the Earth is 9 mm while the Earth radius is about 6000 km. This factor being 10^(-12) makes negligible the effect with respect to the behaviour of the electromagnetic field inside the cavity.
Does the Flight Thruster have a slightly concave top and convex bottom? Would appear so from the gaps.Enhanced the photo as much as I can for those wishing to try to extract dimensions as this photo is better that the original as it has no distortion.If we can find the dimensions of the bottom Rf connector flange, we can set pixels per cm and start doing measurements.
Quote from: Mulletron on 01/25/2015 08:56 amWent back to investigate what I reported in post #233 http://forum.nasaspaceflight.com/index.php?topic=36313.msg1318683#msg1318683 about the RF and Microwave Toolbox app. I found that the app is reporting the correct solutions for TE and TM. The help file just had a typo. I verified it against the KWOK lectures http://www.engr.sjsu.edu/rkwok/EE172/Cavity_Resonator.pdf slide 16. KWOK and the APP match. So this works as a quick and easy way to find resonant modes! There really is an app for everything. I remain unconvinced that calculating resonant modes for cylinders is a good approximation for conical frustums though.The problem as I see it with the cylindrical resonate model to the (in progress) frustum resonate model is in the cylinder model the guide wavelength / frequency stays the same from one end to the other, while in the frustum, the guide wavelength / frequency continually varies as the diameter varies.As example in your frustum big end = 0.2797m dia & small = 0.1588m dia and 2.45GHz applied Rf frequency. Guide wavelengths / frequencies: big end = 0.12654m / 2.368,462,699Ghz small end = 0.13703m / 2.187,156,644GHz diff (big-small) = -0.010490m / 0.181,306,055GHzData attached.These are guide wavelength / frequency and NOT cut off wavelength/frequencies. At 2.45GHz, both of your ends operate well above cutoff.So for your frustum, operating at 2.45GHZ, there is a 181.3MHz difference in the guide frequencies at each end.Trying to imagine what this would look like. Can easily see a cylindrical model with constant guide wavelength from end to end. I may be wrong but as I see it cavity resonance occurs at the internal guide wavelength and not at the external applied Rf wavelength. We know the guide frequency at each end of the frustum, so how to get the applied Rf frequency that causes end plate to end plate resonance at 1/2 wave or other harmonic of some internal guide frequency?
You can get a reasonably close approximation to the exact expression for the natural frequencies of a truncated cone
Quote from: TheTraveller on 05/15/2015 07:36 amDoes the Flight Thruster have a slightly concave top and convex bottom? Would appear so from the gaps.Enhanced the photo as much as I can for those wishing to try to extract dimensions as this photo is better that the original as it has no distortion.If we can find the dimensions of the bottom Rf connector flange, we can set pixels per cm and start doing measurements.Most N connectors like that are 1" square, and the holes are .718" center line to center line.Pixel away.
Quote from: Rodal on 05/15/2015 05:45 pmYou can get a reasonably close approximation to the exact expression for the natural frequencies of a truncated coneWhat is the "exact expression for the natural frequencies of a truncated cone"?Why go with close estimates?
The competitionhttp://nextbigfuture.com/2015/05/photonic-laser-thruster-has-moved-one.html
Quote from: LasJayhawk on 05/15/2015 05:42 pmQuote from: TheTraveller on 05/15/2015 07:36 amDoes the Flight Thruster have a slightly concave top and convex bottom? Would appear so from the gaps.Enhanced the photo as much as I can for those wishing to try to extract dimensions as this photo is better that the original as it has no distortion.If we can find the dimensions of the bottom Rf connector flange, we can set pixels per cm and start doing measurements.Most N connectors like that are 1" square, and the holes are .718" center line to center line.Pixel away. Thanks. Have fine rotated to vertical / horizontal and lined up. Attached if anyone else wants to have a go.
Quote from: deltaMass on 05/15/2015 07:13 pmThe competitionhttp://nextbigfuture.com/2015/05/photonic-laser-thruster-has-moved-one.htmlThat's what I'm talking about! Something like this would be at least 20% more efficient than an EM Drive could ever be. IMO, no competition... Todd D.
I can see future development that includes optical cavities that span many kilometers achieved with precise mirror alignment to enable maneuvering spacecraft many kilometers apart, and propellant-free propulsion of satellites in formations.
Quote from: TheTraveller on 05/15/2015 06:10 pmQuote from: LasJayhawk on 05/15/2015 05:42 pmQuote from: TheTraveller on 05/15/2015 07:36 amDoes the Flight Thruster have a slightly concave top and convex bottom? Would appear so from the gaps.Enhanced the photo as much as I can for those wishing to try to extract dimensions as this photo is better that the original as it has no distortion.If we can find the dimensions of the bottom Rf connector flange, we can set pixels per cm and start doing measurements.Most N connectors like that are 1" square, and the holes are .718" center line to center line.Pixel away. Thanks. Have fine rotated to vertical / horizontal and lined up. Attached if anyone else wants to have a go.If you tell me specifically what measure you are trying to find, and what measures you know with regards to the photo, I might be able to help.
The size of the rectangular section the Flight Thruster is sitting on and the size of the Rf connector flange and mounting hole spacing should be knowable.
Quote from: TheTraveller on 05/15/2015 07:39 amQuote from: Iulian Berca on 05/15/2015 07:31 amYesterday night i did a new test with the Magnetron moved to the small side (10cm from the small side). I patched the previous hole.I also put a coil around one magnet in hope to change the frequency.I ordered a frequency counter, so i will now exactly what is the frequency produced and the intensity.No pendulum movement was observed. The duration of the test was ~40 sec.In the future tests i will be able to observe any change in frequency by modifying the current in the coilIf this will not change the frequency i will modify the frustum to add a moving plate inside.Moving a small internal end plate back and forth was what Shawyer seemed to do to get his cavity into length resonance.As per attached.Would suspect the movable small end plate was very near or at the right end of the cylinder as in the drawing.Yes this is the disk i`m refering. I read almos all this thread and first one, and almost all the papers related to em drive from www.emdrive.comI bought this counter,i should receive it in a few days. .I want to know if i can change the magnetron frequency. It`s working up to 2,6Ghz and it also has signal strength indicator, so i can check for leaks.Here you can buy from ebay. http://www.ebay.com/itm/Black-Mini-Frequency-Counter-IBQ101-Handheld-LCD-Display-HoT-Counter-/171299666945?_trksid=p2054897.l4275
Quote from: Iulian Berca on 05/15/2015 07:31 amYesterday night i did a new test with the Magnetron moved to the small side (10cm from the small side). I patched the previous hole.I also put a coil around one magnet in hope to change the frequency.I ordered a frequency counter, so i will now exactly what is the frequency produced and the intensity.No pendulum movement was observed. The duration of the test was ~40 sec.In the future tests i will be able to observe any change in frequency by modifying the current in the coilIf this will not change the frequency i will modify the frustum to add a moving plate inside.Moving a small internal end plate back and forth was what Shawyer seemed to do to get his cavity into length resonance.As per attached.Would suspect the movable small end plate was very near or at the right end of the cylinder as in the drawing.
Yesterday night i did a new test with the Magnetron moved to the small side (10cm from the small side). I patched the previous hole.I also put a coil around one magnet in hope to change the frequency.I ordered a frequency counter, so i will now exactly what is the frequency produced and the intensity.No pendulum movement was observed. The duration of the test was ~40 sec.In the future tests i will be able to observe any change in frequency by modifying the current in the coilIf this will not change the frequency i will modify the frustum to add a moving plate inside.