Quote from: Rodal on 06/12/2015 02:13 am...It is amazing that Yang achieves record thrust force and record thrust force/powerInput by doing the complete opposite of common wisdom:* lowest Q of any recorded test (common wisdom: highest Q the better)* smallest cone angle, closest to cylinder (common wisdom: highest cone angle the better)* longer cavity than Shawyer's Demo at same small diameter* smaller big diameter than Shawyer's Demo at same small diameter (common wisdom: the larger the big diameter the better)...1. Q represents energy stored. If ALL the energy is stored, it doesn't do any "work". A lower Q does not imply more waste, it implies more work is being done. It can be due to thrust or heat....Todd
...It is amazing that Yang achieves record thrust force and record thrust force/powerInput by doing the complete opposite of common wisdom:* lowest Q of any recorded test (common wisdom: highest Q the better)* smallest cone angle, closest to cylinder (common wisdom: highest cone angle the better)* longer cavity than Shawyer's Demo at same small diameter* smaller big diameter than Shawyer's Demo at same small diameter (common wisdom: the larger the big diameter the better)...
Quote from: WarpTech on 06/12/2015 06:50 am1. Q represents energy stored. If ALL the energy is stored, it doesn't do any "work". A lower Q does not imply more waste, it implies more work is being done. It can be due to thrust or heat....ToddAssuming your perspective on Q, wouldn't you eventually want to build a cavity where the energy lots it heat is drastically reduced. So that there is more energy to do work via attenuation? If so would simply building a super conducting frustum do the trick, Or would super-conduction also reduce attenuation?
1. Q represents energy stored. If ALL the energy is stored, it doesn't do any "work". A lower Q does not imply more waste, it implies more work is being done. It can be due to thrust or heat....Todd
Thus, the geometrical attenuation theory is in accord with experiments also in this respect, as the experiments show that the highest thrust forces have been produced without dielectric inserts.
Quote from: dustinthewind on 06/12/2015 08:46 am...Hmm this gets me thinking about the standing or non-standing waves in the cavity. Let us say, that for some reason attenuation of light is happening at the top end so reflected light is weaker than light from the bottom. As a result the wave is no longer a standing wave and is instead a traveling wave or semi (standing-traveling wave). We all know if you hold a magnet near an aluminum plate and move it it will drag the plate because of the resistance to change in magnetic field. So maybe the semi-traveling waves could do the same to the cavity and drag it along? Does that sound like a possibility? You can move an object by using a magnet from the outside.However you cannot accelerate the center of mass of an object by moving a magnet inside it.An Astronaut with a powerful magnet inside the ISS can move the magnet all she/he wants, and still will not be able to accelerate the center of mass of the ISS.
...Hmm this gets me thinking about the standing or non-standing waves in the cavity. Let us say, that for some reason attenuation of light is happening at the top end so reflected light is weaker than light from the bottom. As a result the wave is no longer a standing wave and is instead a traveling wave or semi (standing-traveling wave). We all know if you hold a magnet near an aluminum plate and move it it will drag the plate because of the resistance to change in magnetic field. So maybe the semi-traveling waves could do the same to the cavity and drag it along? Does that sound like a possibility?
Quote from: Rodal on 06/12/2015 11:46 am Thus, the geometrical attenuation theory is in accord with experiments also in this respect, as the experiments show that the highest thrust forces have been produced without dielectric inserts.I'm starting to get the impression EW did everything possible not to get thrust.
Quote from: Dortex on 06/12/2015 04:05 pmQuote from: Rodal on 06/12/2015 11:46 am Thus, the geometrical attenuation theory is in accord with experiments also in this respect, as the experiments show that the highest thrust forces have been produced without dielectric inserts.I'm starting to get the impression EW did everything possible not to get thrust.Curious statement, why would they move in that direction?
Quote from: birchoff on 06/12/2015 02:36 pmQuote from: WarpTech on 06/12/2015 06:50 am1. Q represents energy stored. If ALL the energy is stored, it doesn't do any "work". A lower Q does not imply more waste, it implies more work is being done. It can be due to thrust or heat....ToddAssuming your perspective on Q, wouldn't you eventually want to build a cavity where the energy lots it heat is drastically reduced. So that there is more energy to do work via attenuation? If so would simply building a super conducting frustum do the trick, Or would super-conduction also reduce attenuation?IMO a superconducting frustum, that is longer with a much lower cone angle should exhibit more thrust and less loss to heat. The attenuation, I've learned is caused by the phase differences causing pressure imbalance, not resistive "heat" losses. Consider this a game of tug-of-war. Both teams (pressures) are pushing equally in both directions, but when one team lets go of the rope, the other team experiences "thrust". In this case, the team that lets go, is the destructive interference at one end, and constructive interference at the other end gets to hold onto the rope, er, I mean frustum. Todd
I'm still fooling with meep, trying to get some 3D images and yesterday I had an interesting accident with the code. Using what I thought was a sealed "Bradycone" cavity in 3D, I continued to see extensive RF energy outside the cone. Of course that can not be as we understand things. I made a Force/Power run and meep measured 10+ times ideal photon rocket.On further investigation i discovered that I had modeled the dielectric shifted in the Y direction - sideways - instead of axially. (Meep uses different coordinates in 3D that in 2D, it seems) So with the dielectric penetrating the center of one of the sidewalls of the cone (still oriented with dielectric and cavity ends parallel) F/P was 10 times higher than typical. OH, and this model won't resonate, that's where my investigation started.I don't know if the above is meaningful but I found it interesting. I wish someone else would do some FDTD runs so I would have someone to discuss wierd resiults with.
Quote from: aero on 06/12/2015 04:01 pmI'm still fooling with meep, trying to get some 3D images and yesterday I had an interesting accident with the code. Using what I thought was a sealed "Bradycone" cavity in 3D, I continued to see extensive RF energy outside the cone. Of course that can not be as we understand things. I made a Force/Power run and meep measured 10+ times ideal photon rocket.On further investigation i discovered that I had modeled the dielectric shifted in the Y direction - sideways - instead of axially. (Meep uses different coordinates in 3D that in 2D, it seems) So with the dielectric penetrating the center of one of the sidewalls of the cone (still oriented with dielectric and cavity ends parallel) F/P was 10 times higher than typical. OH, and this model won't resonate, that's where my investigation started.I don't know if the above is meaningful but I found it interesting. I wish someone else would do some FDTD runs so I would have someone to discuss wierd resiults with.I'm just digging into it so I need some more time, it's not easy to learn. When I feel I can offer some intelligent bread crumbs I'll speak up.But your right that is a weird result.Shell
Quote from: WarpTech on 06/12/2015 03:44 pmQuote from: birchoff on 06/12/2015 02:36 pmQuote from: WarpTech on 06/12/2015 06:50 am1. Q represents energy stored. If ALL the energy is stored, it doesn't do any "work". A lower Q does not imply more waste, it implies more work is being done. It can be due to thrust or heat....ToddAssuming your perspective on Q, wouldn't you eventually want to build a cavity where the energy lots it heat is drastically reduced. So that there is more energy to do work via attenuation? If so would simply building a super conducting frustum do the trick, Or would super-conduction also reduce attenuation?IMO a superconducting frustum, that is longer with a much lower cone angle should exhibit more thrust and less loss to heat. The attenuation, I've learned is caused by the phase differences causing pressure imbalance, not resistive "heat" losses. Consider this a game of tug-of-war. Both teams (pressures) are pushing equally in both directions, but when one team lets go of the rope, the other team experiences "thrust". In this case, the team that lets go, is the destructive interference at one end, and constructive interference at the other end gets to hold onto the rope, er, I mean frustum. ToddThe harmonic wave collapse is towards the small end if I'm gleaning this right? Visualizing on the fly here so forgive me if I muck it up. If I consider the internal Frustum structures of a stabilized harmonic wave pattern, it makes sense that the small end would collapse and decay first (simply less harmonic wave support) into effervescent waves and the large end would "rush" in to fill the void where the EM pattern lost structure in the small end. Whereas they also would also decay into effervescent waves. It seems to tie in with the Chinese using the TM mode as the collapsing harmonics at the large end of the Fructum structure would travel down the center of the Frustum towards the small end?
Quote from: Rodal on 06/12/2015 01:20 amQuote from: Rodal on 06/12/2015 12:44 amQuote from: WarpTech on 06/11/2015 10:18 pm...Hence, why I said the frustum needs to be longer, so we can have something "closer" to Zeng & Fan's waveguide for traveling waves. If we are confined to 0-length past the cut-off diameter, attenuation is minimized, reflection and Q are higher. If we extend it out a full wavelength, we may attenuate 66% of the energy. The other 33% will be reflected with a larger phase shift than what Shawyer's design allows.Also, the standing waves in a damped cavity will also frequency shift due to the damping. That's what gives Shawyer's design "some" thrust, but as I said, it is the rate of attenuation that will exert a higher force. So a longer front end to give the waves some traveling room to be attenuated faster, is what I believe is needed.In other words, "design" the thruster more like Zeng and Fan and less like Shawyer.ToddProf. Yang's EM Drive is significantly longer than Shawyer'sDescription Mode Shape Length (m) Db (m) Ds (m) Frequency (GHz) Q Force / PowerInput (mN/kW)Shawyer Demo TE012 0.187 0.28 0.14921 2.45 45000 80-243Yang TE012 0.24 0.201 0.1492 2.45 1531 1070Both have the same frequency, same mode shape, same Small Diameter Yang achieves 10 to 5 times greater force/input power by operating with 29 times lower Q with a 28% longer EM Drive and 39% smaller big diameter. All the opposite of what Shawyer recommends.The wavelength is 299700000 m/s /(2.45*10^9 1/s) = 0.122 mSo Yang's EM Drive (which has the same small diameter as Shawyer's Demo) has a length (0.24 - 0.187) = 0.053 mYang's EM Drive is therefore about 1/2 wavelength longer than Shawyer's EM Drive truncated cone lengthThe most important parameter to Zeng & Fan is the cone half-angle. It is drastically different between them:Shawyer (180/Pi) ArcTan[(0.28 - 0.14921)/(2*0.187)] = 19.275 degreesYang (180/Pi) ArcTan[(0.201 - 0.1492)/(2*0.24)] = 6.159 degreesShawyer's EM Drive has a cone half-angle more than 3 times greater.Yang's EM Drive is closer to a cylinder, which according to Zeng & Fan results in much greater attenuation.Thank you for validating everything I just said!
Quote from: Rodal on 06/12/2015 12:44 amQuote from: WarpTech on 06/11/2015 10:18 pm...Hence, why I said the frustum needs to be longer, so we can have something "closer" to Zeng & Fan's waveguide for traveling waves. If we are confined to 0-length past the cut-off diameter, attenuation is minimized, reflection and Q are higher. If we extend it out a full wavelength, we may attenuate 66% of the energy. The other 33% will be reflected with a larger phase shift than what Shawyer's design allows.Also, the standing waves in a damped cavity will also frequency shift due to the damping. That's what gives Shawyer's design "some" thrust, but as I said, it is the rate of attenuation that will exert a higher force. So a longer front end to give the waves some traveling room to be attenuated faster, is what I believe is needed.In other words, "design" the thruster more like Zeng and Fan and less like Shawyer.ToddProf. Yang's EM Drive is significantly longer than Shawyer'sDescription Mode Shape Length (m) Db (m) Ds (m) Frequency (GHz) Q Force / PowerInput (mN/kW)Shawyer Demo TE012 0.187 0.28 0.14921 2.45 45000 80-243Yang TE012 0.24 0.201 0.1492 2.45 1531 1070Both have the same frequency, same mode shape, same Small Diameter Yang achieves 10 to 5 times greater force/input power by operating with 29 times lower Q with a 28% longer EM Drive and 39% smaller big diameter. All the opposite of what Shawyer recommends.The wavelength is 299700000 m/s /(2.45*10^9 1/s) = 0.122 mSo Yang's EM Drive (which has the same small diameter as Shawyer's Demo) has a length (0.24 - 0.187) = 0.053 mYang's EM Drive is therefore about 1/2 wavelength longer than Shawyer's EM Drive truncated cone lengthThe most important parameter to Zeng & Fan is the cone half-angle. It is drastically different between them:Shawyer (180/Pi) ArcTan[(0.28 - 0.14921)/(2*0.187)] = 19.275 degreesYang (180/Pi) ArcTan[(0.201 - 0.1492)/(2*0.24)] = 6.159 degreesShawyer's EM Drive has a cone half-angle more than 3 times greater.Yang's EM Drive is closer to a cylinder, which according to Zeng & Fan results in much greater attenuation.
Quote from: WarpTech on 06/11/2015 10:18 pm...Hence, why I said the frustum needs to be longer, so we can have something "closer" to Zeng & Fan's waveguide for traveling waves. If we are confined to 0-length past the cut-off diameter, attenuation is minimized, reflection and Q are higher. If we extend it out a full wavelength, we may attenuate 66% of the energy. The other 33% will be reflected with a larger phase shift than what Shawyer's design allows.Also, the standing waves in a damped cavity will also frequency shift due to the damping. That's what gives Shawyer's design "some" thrust, but as I said, it is the rate of attenuation that will exert a higher force. So a longer front end to give the waves some traveling room to be attenuated faster, is what I believe is needed.In other words, "design" the thruster more like Zeng and Fan and less like Shawyer.ToddProf. Yang's EM Drive is significantly longer than Shawyer'sDescription Mode Shape Length (m) Db (m) Ds (m) Frequency (GHz) Q Force / PowerInput (mN/kW)Shawyer Demo TE012 0.187 0.28 0.14921 2.45 45000 80-243Yang TE012 0.24 0.201 0.1492 2.45 1531 1070Both have the same frequency, same mode shape, same Small Diameter Yang achieves 10 to 5 times greater force/input power by operating with 29 times lower Q with a 28% longer EM Drive and 39% smaller big diameter. All the opposite of what Shawyer recommends.The wavelength is 299700000 m/s /(2.45*10^9 1/s) = 0.122 mSo Yang's EM Drive (which has the same small diameter as Shawyer's Demo) has a length (0.24 - 0.187) = 0.053 mYang's EM Drive is therefore about 1/2 wavelength longer than Shawyer's EM Drive truncated cone length
...Hence, why I said the frustum needs to be longer, so we can have something "closer" to Zeng & Fan's waveguide for traveling waves. If we are confined to 0-length past the cut-off diameter, attenuation is minimized, reflection and Q are higher. If we extend it out a full wavelength, we may attenuate 66% of the energy. The other 33% will be reflected with a larger phase shift than what Shawyer's design allows.Also, the standing waves in a damped cavity will also frequency shift due to the damping. That's what gives Shawyer's design "some" thrust, but as I said, it is the rate of attenuation that will exert a higher force. So a longer front end to give the waves some traveling room to be attenuated faster, is what I believe is needed.In other words, "design" the thruster more like Zeng and Fan and less like Shawyer.Todd
Quote from: SeeShells on 06/12/2015 05:21 pmQuote from: aero on 06/12/2015 04:01 pmI'm still fooling with meep, trying to get some 3D images and yesterday I had an interesting accident with the code. Using what I thought was a sealed "Bradycone" cavity in 3D, I continued to see extensive RF energy outside the cone. Of course that can not be as we understand things. I made a Force/Power run and meep measured 10+ times ideal photon rocket.On further investigation i discovered that I had modeled the dielectric shifted in the Y direction - sideways - instead of axially. (Meep uses different coordinates in 3D that in 2D, it seems) So with the dielectric penetrating the center of one of the sidewalls of the cone (still oriented with dielectric and cavity ends parallel) F/P was 10 times higher than typical. OH, and this model won't resonate, that's where my investigation started.I don't know if the above is meaningful but I found it interesting. I wish someone else would do some FDTD runs so I would have someone to discuss wierd resiults with.I'm just digging into it so I need some more time, it's not easy to learn. When I feel I can offer some intelligent bread crumbs I'll speak up.But your right that is a weird result.ShellOh thank you, thank you! It took me about 2 months in a vacuum to get my first valid Force/Power run working, but then I've had more time to forget my education than you have. About 5 years more, if my gleaning from your remarks is correct. That, and side trips into Maxima and ParaView made my progress a little slow.I hope you won't need to study Meep in a vacuum though. Ask, or PM me if you have questions about Meep that you'd rather not share with the forum.
...Also the longer length of the Chinese Frustum makes sense with the sidewalls of the Frustum not attenuating as it (less angle) collapses into the smaller end. Longer distance traveled = higher Momentum gained and speed through less loss, a more focused effervescent wave collapse?
Quote from: WarpTech on 06/12/2015 01:53 amQuote from: Rodal on 06/12/2015 01:20 amQuote from: Rodal on 06/12/2015 12:44 amQuote from: WarpTech on 06/11/2015 10:18 pm...Hence, why I said the frustum needs to be longer, so we can have something "closer" to Zeng & Fan's waveguide for traveling waves. If we are confined to 0-length past the cut-off diameter, attenuation is minimized, reflection and Q are higher. If we extend it out a full wavelength, we may attenuate 66% of the energy. The other 33% will be reflected with a larger phase shift than what Shawyer's design allows.Also, the standing waves in a damped cavity will also frequency shift due to the damping. That's what gives Shawyer's design "some" thrust, but as I said, it is the rate of attenuation that will exert a higher force. So a longer front end to give the waves some traveling room to be attenuated faster, is what I believe is needed.In other words, "design" the thruster more like Zeng and Fan and less like Shawyer.ToddProf. Yang's EM Drive is significantly longer than Shawyer'sDescription Mode Shape Length (m) Db (m) Ds (m) Frequency (GHz) Q Force / PowerInput (mN/kW)Shawyer Demo TE012 0.187 0.28 0.14921 2.45 45000 80-243Yang TE012 0.24 0.201 0.1492 2.45 1531 1070Both have the same frequency, same mode shape, same Small Diameter Yang achieves 10 to 5 times greater force/input power by operating with 29 times lower Q with a 28% longer EM Drive and 39% smaller big diameter. All the opposite of what Shawyer recommends.The wavelength is 299700000 m/s /(2.45*10^9 1/s) = 0.122 mSo Yang's EM Drive (which has the same small diameter as Shawyer's Demo) has a length (0.24 - 0.187) = 0.053 mYang's EM Drive is therefore about 1/2 wavelength longer than Shawyer's EM Drive truncated cone lengthThe most important parameter to Zeng & Fan is the cone half-angle. It is drastically different between them:Shawyer (180/Pi) ArcTan[(0.28 - 0.14921)/(2*0.187)] = 19.275 degreesYang (180/Pi) ArcTan[(0.201 - 0.1492)/(2*0.24)] = 6.159 degreesShawyer's EM Drive has a cone half-angle more than 3 times greater.Yang's EM Drive is closer to a cylinder, which according to Zeng & Fan results in much greater attenuation.Thank you for validating everything I just said! I have now added the dimensions of the EM Drive cavities used in experiments, figured out in spherical coordinates, which is the natural system to use for the microwaves inside the cavity (they are spherical waves), to the wiki page for Experimental Results:http://emdrive.wiki/Experimental_ResultsOf these spherical geometry parameters, Zeng and Fan single out the cone half angle as the most important, as the geometrical attenuation is a very strong function of the cone half angle.Zeng and Fan show data for 7.5 degrees, 15 degrees, up to 90 degrees in 7.5 degree increments.They show that the largest attenuation by far occurs at 7.5 degrees.It is fascinating, again that Yang achieves 10 to 5 times greater force/input power by operating with 29 times lower Q with a cone half angle of 6 degrees, while Shawyer's EM Drive has a cone half-angle more than 3 times greater.
Curious statement, why would they move in that direction?
Quote from: Rodal on 06/12/2015 02:21 pmHow do we know that the truncated cone entropy distribution is maximized in an accelerated frame or reference?This has been the cause of much discussions in these threads, for example @frobnicat, @deltaMass and @wallofwolfstreet insisting that there is no preferred frame of reference, that the photons don't accelerate, and that everything should be based on frame-indifference. They insist on applying frame-indifference to the cavity.To be fair, doesn't the bulk of experimental evidence outside the realm of EM Drives support frame indifference?
How do we know that the truncated cone entropy distribution is maximized in an accelerated frame or reference?This has been the cause of much discussions in these threads, for example @frobnicat, @deltaMass and @wallofwolfstreet insisting that there is no preferred frame of reference, that the photons don't accelerate, and that everything should be based on frame-indifference. They insist on applying frame-indifference to the cavity.
Quote from: SeeShells on 06/12/2015 05:43 pm...Also the longer length of the Chinese Frustum makes sense with the sidewalls of the Frustum not attenuating as it (less angle) collapses into the smaller end. Longer distance traveled = higher Momentum gained and speed through less loss, a more focused effervescent wave collapse?OK, I need your help here Shell.I understand Zeng and Fan's paper analytically, that the smaller the half-angle the greater the attenuation, but I don't have a physical understanding of this to explain it in simple terms. Which means that when it comes down to it, I don't understand really understand it .This is my problem in understanding this:1) A perfect cylinder has no geometrical attenuation: it has no evanescent waves, no progressive cut-off of modes. The modes that are cut-off are the ones that have a bigger diameter than the cylinder, that's it.2) So, how can it be that the biggest geometrical attenuation occurs for the smallest half-angle ? in other words for the geometry that is closest to a cylinder?3) What happens in the limit with the geometrical attenuation as the cone becomes a cylinder (as the half angle becomes zero)? How does one go from the largest geometrical attenuation for a cone to NO geometrical attenuation for a cylinder?
Quote from: SeeShells on 06/12/2015 05:43 pm...Also the longer length of the Chinese Frustum makes sense with the sidewalls of the Frustum not attenuating as it (less angle) collapses into the smaller end. Longer distance traveled = higher Momentum gained and speed through less loss, a more focused effervescent wave collapse?OK, I need your help here Shell.I understand Zeng and Fan's paper analytically, that the smaller the half-angle the greater the attenuation, but I don't have a physical understanding of this to explain it in simple terms. Which it comes down to,it means that I don't understand it really .This is my problem in understanding this:1) A perfect cylinder has no geometrical attenuation: it has no evanescent waves, no progressive cut-off of modes. The modes that are cut-off are the ones that have a bigger diameter than the cylinder, that's it.Yep, that's about it and very well said.2) So, how can it be that the biggest geometrical attenuation occurs for the smallest half-angle ? in other words for the geometry that is closest to a cylinder?The way I see it it it really doesn't matter after the harmonic pattern starts its collapse at the small end. The collapse of the wave functions is part of the Quantum collapse into effervescent waves and where the discussions of any harmonic actions are mute as there aren't any harmonic cavities to support a Quantum environment. All we are left with are the quantum force vectors... I think.http://rationalwiki.org/wiki/Quantum_collapse3) What happens in the limit with the geometrical attenuation as the cone becomes a cylinder (as the half angle becomes zero)? How does one go from the largest geometrical attenuation for a cone to NO geometrical attenuation for a cylinder?I think number 2 answers that.