...At least the Q is almost equal and cannot be the reason for using the propagated cutoff rule.
Quote from: X_RaY on 01/05/2017 07:35 pmSome pages ago I have posted some early results of two different frustum geometries to compare the Q of both.https://forum.nasaspaceflight.com/index.php?topic=41732.msg1624968#msg1624968...At least the Q is almost equal and cannot be the reason for using the propagated cutoff rule.Hi X-Ray,Thank you very much for the detailed simulation analysis! However, I'm a bit curious as to how you came to your final conclusion.If I'm reading your results correctly, the truncated frustum had ~4% higher Ql and Qu. If maximizing Q truly maximizes thrust, then I would assert that your analysis lends credence to the "propagated cutoff rule" rather than refute it. Getting an extra ~4% "thrust" and simultaneously reducing the total mass of the frustum seems like a pretty good engineering optimization.... assuming "thrust" can be shown as proportional to Q.Seems like this latest simulation data might offer a glimpse into how Shawyer came up with his "rule of thumb" for frustum design/construction: ~4% improvement in Q.Ql_truncated/Ql_cone = 37630/36071 = 104.3%Qu_truncated/Qu_cone = 75260/72142 = 104.3%
Some pages ago I have posted some early results of two different frustum geometries to compare the Q of both.https://forum.nasaspaceflight.com/index.php?topic=41732.msg1624968#msg1624968...At least the Q is almost equal and cannot be the reason for using the propagated cutoff rule.
Quote from: X_RaY on 01/05/2017 07:35 pm...At least the Q is almost equal and cannot be the reason for using the propagated cutoff rule.What about comparing to the truncated frustum where the highest current density is "on" the SD end plate, not the side walls? That would be more compliant with Shawyer's advice. I think, if we're going to dissipate power asymmetrically, it should be on the end plate, not the side walls, so the flux that is escaping has the vector in the right direction.
Quote from: WarpTech on 01/05/2017 08:13 pmQuote from: X_RaY on 01/05/2017 07:35 pm...At least the Q is almost equal and cannot be the reason for using the propagated cutoff rule.What about comparing to the truncated frustum where the highest current density is "on" the SD end plate, not the side walls? That would be more compliant with Shawyer's advice. I think, if we're going to dissipate power asymmetrically, it should be on the end plate, not the side walls, so the flux that is escaping has the vector in the right direction.The small end is slightly above cutoff 151.15mm instead of 149.3mmI let the cone angle exact constant.TT stated the currents should be minimized at the endplate.https://forum.nasaspaceflight.com/index.php?topic=41732.msg1624685#msg1624685
As you can see in the first two results the situation differs from calculation to calculate. The reason is slightly different mesh size and coupling factors.
Quote from: X_RaY on 01/05/2017 08:17 pmAs you can see in the first two results the situation differs from calculation to calculate. The reason is slightly different mesh size and coupling factors. Don't forget to include the spherical end-plate frustum with Q of 111,454. That is a pretty significant increase.
Quote from: X_RaY on 01/05/2017 08:21 pmQuote from: WarpTech on 01/05/2017 08:13 pmQuote from: X_RaY on 01/05/2017 07:35 pm...At least the Q is almost equal and cannot be the reason for using the propagated cutoff rule.What about comparing to the truncated frustum where the highest current density is "on" the SD end plate, not the side walls? That would be more compliant with Shawyer's advice. I think, if we're going to dissipate power asymmetrically, it should be on the end plate, not the side walls, so the flux that is escaping has the vector in the right direction.The small end is slightly above cutoff 151.15mm instead of 149.3mmI let the cone angle exact constant.TT stated the currents should be minimized at the endplate.https://forum.nasaspaceflight.com/index.php?topic=41732.msg1624685#msg1624685Yea, I disagree. If the big end is leading when it's accelerating, then we want the power dissipation "on" the SD end plate.
So the mass I've been looking for in order to locate a mass current for the gravitomagnetic equations...(so far effective mass of photons in resonators and waveguide, in materials, photons in a box contributing to overall mass of the box...etc) but one I hadn't considered is (to me the wiser choice now) is the center of mass of a counter-propagating two photon system. Also apply this in the context of a partial standing wave, and the concept is definitely clicking.
Quote from: WarpTech on 01/05/2017 08:28 pmQuote from: X_RaY on 01/05/2017 08:21 pmQuote from: WarpTech on 01/05/2017 08:13 pmQuote from: X_RaY on 01/05/2017 07:35 pm...At least the Q is almost equal and cannot be the reason for using the propagated cutoff rule.What about comparing to the truncated frustum where the highest current density is "on" the SD end plate, not the side walls? That would be more compliant with Shawyer's advice. I think, if we're going to dissipate power asymmetrically, it should be on the end plate, not the side walls, so the flux that is escaping has the vector in the right direction.The small end is slightly above cutoff 151.15mm instead of 149.3mmI let the cone angle exact constant.TT stated the currents should be minimized at the endplate.https://forum.nasaspaceflight.com/index.php?topic=41732.msg1624685#msg1624685Yea, I disagree. If the big end is leading when it's accelerating, then we want the power dissipation "on" the SD end plate.why at the end plate now instead of the "small end" at all?I don't know if the shown design produces thrust at all. I don't know if one will show more thrust than the other design. The goal was to find out what happens to the Q-factor when one plate is below the cutoff rule.
Quote from: Monomorphic on 01/05/2017 08:31 pmQuote from: X_RaY on 01/05/2017 08:17 pmAs you can see in the first two results the situation differs from calculation to calculate. The reason is slightly different mesh size and coupling factors. Don't forget to include the spherical end-plate frustum with Q of 111,454. That is a pretty significant increase.Again, at the moment I don't believe in this Q values based on calculations with HOBF. I get freaky inconclusive results when using it.EDITThis is the same frustum as used for the Q compare but using HOBF and fine mesh. Instead of natural possible QL~36000, i get 207000 loaded Q!
Quote from: WarpTech on 01/05/2017 09:15 pmBecause this is comparing 2 frustums where "both" have the power dissipation in the side walls, and your result is that they are almost identical Q values. If we want to see a significant difference in Q, we need to compare two frustums that do NOT both have dissipation on the side walls. One would be on the side walls and the truncated one on the end plate. Think of the small end plate as a partially reflective mirror at one end of a MASER. This is the "output" end of the resonator, and we want the output to be as collimated as possible. I for one would like to know the difference in Q values. It might actually be higher in that configuration.I could make the frustum even shorter to trigger this pattern at the end plate, should be interesting to get this data too Whatever this means for any thrust generation.It will take a while.. .
Because this is comparing 2 frustums where "both" have the power dissipation in the side walls, and your result is that they are almost identical Q values. If we want to see a significant difference in Q, we need to compare two frustums that do NOT both have dissipation on the side walls. One would be on the side walls and the truncated one on the end plate. Think of the small end plate as a partially reflective mirror at one end of a MASER. This is the "output" end of the resonator, and we want the output to be as collimated as possible. I for one would like to know the difference in Q values. It might actually be higher in that configuration.
Quote from: X_RaY on 01/05/2017 08:34 pmQuote from: Monomorphic on 01/05/2017 08:31 pmQuote from: X_RaY on 01/05/2017 08:17 pmAs you can see in the first two results the situation differs from calculation to calculate. The reason is slightly different mesh size and coupling factors. Don't forget to include the spherical end-plate frustum with Q of 111,454. That is a pretty significant increase.Again, at the moment I don't believe in this Q values based on calculations with HOBF. I get freaky inconclusive results when using it.EDITThis is the same frustum as used for the Q compare but using HOBF and fine mesh. Instead of natural possible QL~36000, i get 207000 loaded Q! Can EmPro calculate Q?If yes can you check the results with EmPro?
Yes, and much easier, it's scheduled after holidays. Cant say when exactly I have time then to do this. I will let you know.
Quote from: rfmwguy on 01/05/2017 12:00 pmQuote from: Mulletron on 01/05/2017 11:33 amSo the mass I've been looking for in order to locate a mass current for the gravitomagnetic equations...(so far effective mass of photons in resonators and waveguide, in materials, photons in a box contributing to overall mass of the box...etc) but one I hadn't considered is (to me the wiser choice now) is the center of mass of a counter-propagating two photon system. Also apply this in the context of a partial standing wave, and the concept is definitely clicking. Good find. Perhaps this explains why Paul M suggests emdrive performance is enhanced when drive signal freq is slightly off cavity resonance...a condition which should create partial standing waves...which are directional. I might visualize the partial standing wave being able to travel in either direction dependent upon whether the drive freq is above or below resonance peak...which corresponds to deflection forces both forwards and backwards in relation to small and large endplates...which just gave me a brain cramp Rfmwguy, that idea of yours just triggered my memory. For a long time, I was wondering what unforeseen effect the magnetron experiments may have had, that would not easily (at least not automatically) be replicated in solid state systems.One possibly large effect will be the particular combination of phase-shifted AM and FM. The magnetron has 100% AM modulation depth at 50 (60) Hz, due to the single diode power supply. However it also has some FM, as evident by the splatter spectra that people had posted here last year. What is interesting however, is that the FM is to a large extent due to magnetron-internal thermal effects, therefore it is phase delayed compared to the AM because of thermal time constants.What so far nobody seems to have tested with solid state systems is such an AM+FM signal. To maximize the effect, it would need a modulation signal source with separate sine and cosine outputs (I and Q), with I being applied to the frequency control of the RF VCO (working as frequency modulator) and with Q being applied to the gain control of a variable gain amplifier (working as amplitude modulator). This would create a signal that goes up in frequency (through the center) while at its maximal amplitude and that goes down in frequency while the amplitude is minimal, thereby working like an "unidirectional on average" upwards sweep signal (or a downward sweep if you swap the signal generator polarity). If I'm not mistaken, this may result in a net unidirectional travelling wave like pattern in the resonator.We may have had that pattern almost forever with the magnetron experiments and nobody realizing its potential siginficance. And then, precision solid state experiments get done with extremely stable signals, and report null results!
Quote from: Mulletron on 01/05/2017 11:33 amSo the mass I've been looking for in order to locate a mass current for the gravitomagnetic equations...(so far effective mass of photons in resonators and waveguide, in materials, photons in a box contributing to overall mass of the box...etc) but one I hadn't considered is (to me the wiser choice now) is the center of mass of a counter-propagating two photon system. Also apply this in the context of a partial standing wave, and the concept is definitely clicking. Good find. Perhaps this explains why Paul M suggests emdrive performance is enhanced when drive signal freq is slightly off cavity resonance...a condition which should create partial standing waves...which are directional. I might visualize the partial standing wave being able to travel in either direction dependent upon whether the drive freq is above or below resonance peak...which corresponds to deflection forces both forwards and backwards in relation to small and large endplates...which just gave me a brain cramp
Again, at the moment I don't believe in this Q values based on calculations with HOBF. I get freaky inconclusive results when using it.EDITThis is the same frustum as used for the Q compare but using HOBF and fine mesh. Instead of natural possible QL~36000, i get 207000 loaded Q!
Does anyone have the dimensions and frequency for this build? Can they share them? FL
...The caveat here is the RF source is in the same frame of reference and should not allow asymmetrical momentum in one direction unless we can somehow invoke the outside world and make it an open system. This is where I hit a brick wall...where would asymmetrical momentum be from? External fields or the "vacuum".Sorry, I have no answers.
Quote from: FattyLumpkin on 01/05/2017 11:01 pmDoes anyone have the dimensions and frequency for this build? Can they share them? FLThat's rfmwguy's NSF1701A. TE013 at ~2.83Ghz.
Quote from: Monomorphic on 01/05/2017 11:03 pmQuote from: FattyLumpkin on 01/05/2017 11:01 pmDoes anyone have the dimensions and frequency for this build? Can they share them? FLThat's rfmwguy's NSF1701A. TE013 at ~2.83Ghz.We know. What are the dimensions please? Dave's data is not in the wiki.