Using the following dimensions:Length: 138.6mmSmall diameter: 125.7mmBig diameter: 231.4mmand using the speed of light in air:cAir = 299705000 (meter/s)My exact solution gives:Mode: TE013Frequency: 3.94571 GHzMode: TE012Frequency: 3.10927 GHzMode: TE011Frequency: 2.37833 GHzSo the question is: why are you going to excite this with TE013 at 3.95GHz, when you could be exiting it a 2.38 GHz (a frequency much closer to the usual magnetron frequency) in mode TE011 which should give you a greater amplitude (*) ?Does your spreadsheet predict that you are going to get a higher thrust force with TE013 than with TE011 ?Both modes TE011 and TE013 have identical electromagnetic field variation in the circular cross-section, the only difference is that TE013 has a higher frequency variation in the longitudinal direction.(*) 1) Amplitude of mode shapes decreases with frequency, in general, for all kinds of vibrations and 2) Look at Notsosureofit's thrust force formula
I'm just gonna leave this here..."Macroscopic and Direct Light Propulsion of Bulk Graphene Material"http://arxiv.org/ftp/arxiv/papers/1505/1505.04254.pdfQuoteThe force generated from such a process/mechanism is muchlarger than the force generated directly from the conventional light pressure, which ismuch smaller than the force required to propel the samples. QuoteThe mechanism behind this novel phenomenon is believed to be anefficient light-induced ejected electron emission process, following an Auger-like pathdue to both the unique band structure of graphene and its macroscopic morphology ofthis unique material.
The force generated from such a process/mechanism is muchlarger than the force generated directly from the conventional light pressure, which ismuch smaller than the force required to propel the samples.
The mechanism behind this novel phenomenon is believed to be anefficient light-induced ejected electron emission process, following an Auger-like pathdue to both the unique band structure of graphene and its macroscopic morphology ofthis unique material.
The only advantage I see with TE013 is that it has the Poynting vector concentrated at the small end, and a local high amplitude at the small end.
Quote from: kml on 05/28/2015 07:10 pm...Would TE011 actually work? 2.37GHz is below the TE01 cutoff frequency of 2.9GHz for a cylindrical waveguide of the small end (125cm). TE011 is actually not cut-off according to the exact solution with spherical ends for those dimensions listed above (125.7mm). It looks good and strong, very clear signal in the exact solution.It would have higher attenuation at the small end, which according to Todd's theory -which has my seal of approval - is a plus.I suppose that those that think that attenuation is bad may opt against, but it would be nice to test.The only advantage I see with TE013 is that it has the Poynting vector concentrated at the small end, and a local high amplitude at the small end.
...Would TE011 actually work? 2.37GHz is below the TE01 cutoff frequency of 2.9GHz for a cylindrical waveguide of the small end (125cm).
(...)Oh, here is the link to this paper that has put many things into perspective for me and I think it's a good read.Shellhttp://arxiv.org/pdf/gr-qc/0205066.pdf
Quote from: SeeShells on 05/28/2015 07:37 pm(...)Oh, here is the link to this paper that has put many things into perspective for me and I think it's a good read.Shellhttp://arxiv.org/pdf/gr-qc/0205066.pdfGreat article, struggled abit, but demonstrates the uncertainties between classic and "modern" physics. The CoE/CoM handwavers must sense something is afoot. Pretty sure the resonance/shape frustum cavity is partlally responsible for the apparent "effect" and cranking more power may increase it; but it may reach a point of diminishing returns or thermal/practical limits due to materials knowledge or science. The dielectric material has been of special interest (obsession) to me. Can the "effect" be amplified exponentially, not by an increase in power, but by materials in the small end of the cavity. Guess I'm a fan of lower power experimentation with dielectric material as the only variable from test to test. Might have to break out my soldering iron after all...
Quote from: rfmwguy on 05/28/2015 08:19 pmQuote from: SeeShells on 05/28/2015 07:37 pm(...)Oh, here is the link to this paper that has put many things into perspective for me and I think it's a good read.Shellhttp://arxiv.org/pdf/gr-qc/0205066.pdfGreat article, struggled abit, but demonstrates the uncertainties between classic and "modern" physics. The CoE/CoM handwavers must sense something is afoot. Pretty sure the resonance/shape frustum cavity is partlally responsible for the apparent "effect" and cranking more power may increase it; but it may reach a point of diminishing returns or thermal/practical limits due to materials knowledge or science. The dielectric material has been of special interest (obsession) to me. Can the "effect" be amplified exponentially, not by an increase in power, but by materials in the small end of the cavity. Guess I'm a fan of lower power experimentation with dielectric material as the only variable from test to test. Might have to break out my soldering iron after all... I know, so many want high power and to push it, but you know sometimes you can't hear the band if you bang the drums to hard? I'll tell you this, I also see the "effect" under an influence with another material in the small end, just too many things that are clicking right about it.
Quote from: SeeShells on 05/28/2015 08:30 pmQuote from: rfmwguy on 05/28/2015 08:19 pmQuote from: SeeShells on 05/28/2015 07:37 pm(...)Oh, here is the link to this paper that has put many things into perspective for me and I think it's a good read.Shellhttp://arxiv.org/pdf/gr-qc/0205066.pdfGreat article, struggled abit, but demonstrates the uncertainties between classic and "modern" physics. The CoE/CoM handwavers must sense something is afoot. Pretty sure the resonance/shape frustum cavity is partlally responsible for the apparent "effect" and cranking more power may increase it; but it may reach a point of diminishing returns or thermal/practical limits due to materials knowledge or science. The dielectric material has been of special interest (obsession) to me. Can the "effect" be amplified exponentially, not by an increase in power, but by materials in the small end of the cavity. Guess I'm a fan of lower power experimentation with dielectric material as the only variable from test to test. Might have to break out my soldering iron after all... I know, so many want high power and to push it, but you know sometimes you can't hear the band if you bang the drums to hard? I'll tell you this, I also see the "effect" under an influence with another material in the small end, just too many things that are clicking right about it. Yes, Shell, I'd start with cavity optimization, then dielectric, then power. Dielectric variables can be "tuned" as shown in Shawyer's model and Iulian is replicating. These threads seem to be focused on cavity discussions/optimization which is needed, but phase 2 could be dielectrics...guess i'm jumping ahead too soon
Quote from: SeeShells on 05/28/2015 08:30 pmQuote from: rfmwguy on 05/28/2015 08:19 pmQuote from: SeeShells on 05/28/2015 07:37 pm(...)Oh, here is the link to this paper that has put many things into perspective for me and I think it's a good read.Shellhttp://arxiv.org/pdf/gr-qc/0205066.pdfYes, Shell, I'd start with cavity optimization, then dielectric, then power. Dielectric variables can be "tuned" as shown in Shawyer's model and Iulian is replicating. These threads seem to be focused on cavity discussions/optimization which is needed, but phase 2 could be dielectrics...guess i'm jumping ahead too soon No you're right, you never design the cart before you get the horse. In the design you need to make room for a baseline design and that includes variable input frequencies, multiple injection points, phase shifting, a cavity that's tunable, easy disassembly and assembly, different materials and test equipment and the list goes on and on. I've had engineers working for me that wanted to build a running Cadillac when all we needed was a wheel to get rolling and we could add another one if needed.
Quote from: rfmwguy on 05/28/2015 08:19 pmQuote from: SeeShells on 05/28/2015 07:37 pm(...)Oh, here is the link to this paper that has put many things into perspective for me and I think it's a good read.Shellhttp://arxiv.org/pdf/gr-qc/0205066.pdfYes, Shell, I'd start with cavity optimization, then dielectric, then power. Dielectric variables can be "tuned" as shown in Shawyer's model and Iulian is replicating. These threads seem to be focused on cavity discussions/optimization which is needed, but phase 2 could be dielectrics...guess i'm jumping ahead too soon
Quote from: SeeShells on 05/28/2015 07:37 pm(...)Oh, here is the link to this paper that has put many things into perspective for me and I think it's a good read.Shellhttp://arxiv.org/pdf/gr-qc/0205066.pdf
Quote from: Paul Novy on 05/28/2015 07:49 amI'm just gonna leave this here..."Macroscopic and Direct Light Propulsion of Bulk Graphene Material"http://arxiv.org/ftp/arxiv/papers/1505/1505.04254.pdfQuoteThe force generated from such a process/mechanism is muchlarger than the force generated directly from the conventional light pressure, which ismuch smaller than the force required to propel the samples. QuoteThe mechanism behind this novel phenomenon is believed to be anefficient light-induced ejected electron emission process, following an Auger-like pathdue to both the unique band structure of graphene and its macroscopic morphology ofthis unique material. This article is showing that for certain types of materials, light can impart more force to the material, than it would if it were simply used to as a photon rocket to push the same material. The difference is the Auger Effect, where the incoming light causes a population inversion in the material, that then causes electrons to be ejected from the material, greatly increasing the force by many orders of magnitude. Perhaps a similar effect can be obtained asymmetrically in a cavity?Thank you for posting it!Todd
EDIT: Oh, by the way, the Poynting vector frequency is always twice the frequency of the electromagnetic field, its period is 1/2 the period of the electromagnetic field. It reverses direction twice as often as the electromagnetic fields.
QuoteEDIT: Oh, by the way, the Poynting vector frequency is always twice the frequency of the electromagnetic field, its period is 1/2 the period of the electromagnetic field. It reverses direction twice as often as the electromagnetic fields.So the Poynting vector is an even number of cycles no matter the number of half-cycles of the drive frequency. Well, next we ask, is the drive frequency (period, wavelength) always an interger number of half-cycles? Seems it must be in order to resonate but the shape of the cavity and the existance of the dielectric makes one wonder, what is the effective drive frequency as far as the Poynting vector is concerned and does it remain always an even number of cycles everywhere within the cavity? Perhaps a more salient question would be, what is the strength of the Poynting vector force over one-half cycle as that should be the maximum Poynting force attainable, and how does it compare to F = 2PQ/c?
Quote from: aero on 05/28/2015 09:15 pmQuoteEDIT: Oh, by the way, the Poynting vector frequency is always twice the frequency of the electromagnetic field, its period is 1/2 the period of the electromagnetic field. It reverses direction twice as often as the electromagnetic fields.So the Poynting vector is an even number of cycles no matter the number of half-cycles of the drive frequency. Well, next we ask, is the drive frequency (period, wavelength) always an interger number of half-cycles? Seems it must be in order to resonate but the shape of the cavity and the existance of the dielectric makes one wonder, what is the effective drive frequency as far as the Poynting vector is concerned and does it remain always an even number of cycles everywhere within the cavity? Perhaps a more salient question would be, what is the strength of the Poynting vector force over one-half cycle as that should be the maximum Poynting force attainable, and how does it compare to F = 2PQ/c?Only the Experimental EM Drive used an internal small end dielectric. As a result, it had low Q and low thrust.The Demonstrator and Flight Thruster EM Drives are high Q and high thrust devices which did not use a dielectric.Shawyer says using a dielecrtic:1) increases loss,2) reduces Q,3) reduces thrust.His reported results back up that claimSo why the interest in dielectrics?
Quote from: Rodal on 05/28/2015 02:34 pmQuote from: TheTraveller on 05/28/2015 02:10 pmHave asked Roger Shawyer to confirm the quoted Df for the Demonstrator EMDrive is 0.844:http://emdrive.com/demonstratorengine.htmlCan you please ask for him to check his original data documents (rather than his published papers) , and re-calculate the Design Factor based on known geometry, to make sure that there was not an unintended typo somewhere?From work on my spreadsheet, that can easily adopt to various TMm,n and TEm,n modes, I believe it is possible to get an excitation mode that will deliver a high Df, small end operating just above cutoff (as Shawyer recommends), without using stupid geometry.Did ask for the excitation mode. If he shares that, will be able to plug it into my spreadsheet and see what it says about small diameter.The more I work with my spreadsheet, the more I get a good gut feeling about how the 3 dimensions, excitation mode and external Rf frequency interplay with each other to get an optimal mix of all 5 variables for max thrust per applied power.
Quote from: TheTraveller on 05/28/2015 02:10 pmHave asked Roger Shawyer to confirm the quoted Df for the Demonstrator EMDrive is 0.844:http://emdrive.com/demonstratorengine.htmlCan you please ask for him to check his original data documents (rather than his published papers) , and re-calculate the Design Factor based on known geometry, to make sure that there was not an unintended typo somewhere?
Have asked Roger Shawyer to confirm the quoted Df for the Demonstrator EMDrive is 0.844:http://emdrive.com/demonstratorengine.html
Flight Thruster build update:From the best photo of the Flight Thruster I could find and allowing for 2mm thick walls, to add thermal mass and reduce the rate of thermal expansion, the following internal Flight Thruster dimensions were obtained:Length: 138.6mmSmall diameter: 125.7mmBig diameter: 231.4mmApplying those to my spreadsheet generated:Df: 0.638Frequency: 3.85GHzMode: TE013I then asked Roger Shawyer did I get close? His reply:Df: 0.635Frequency: 3.9003GHzMode: TE013I'm VERY happy with that as my Rf gen can easily go to that frequency. Time now to finalise drawings and get some copper sheet laser cut.Roger also mentioned it is best to give the internal frustum surfaces a nice bright shinny polish. No need for Silver or Gold overcoats.
so, no scat, there i was... I learned you can do stuff that violates the laws of physics so long as you label the process as happening in imaginary time even if it has real physical consequences.http://phys.org/news/2015-05-physicists-quantum-tunneling-mystery.htmlSynopsis: Massive things that quantum tunnel can violate the physical speed limit of light so long as there isn't anybody watching and there cannot be anyone watching because it happens in imaginary time.I don't know about you; but i kind of had a different idea of what "imaginary" means but evidently imaginary does NOT mean unreal.