Quote from: TheTraveller on 05/12/2015 01:16 pm..Again:1) I would not display non-physical negative values in a graph (in my Mathematica code, I have an IF condiitional statement to deal with them). That's a personal choice2) You have a big error in your calculation of 20452.053 design factor that you are not addressing in any of your replies. I haven't seen a reply acknowledging your error.

..

Quote from: Rodal on 05/12/2015 01:26 pmQuote from: TheTraveller on 05/12/2015 01:16 pm..Again:1) I would not display non-physical negative values in a graph (in my Mathematica code, I have an IF condiitional statement to deal with them). That's a personal choice2) You have a big error in your calculation of 20452.053 design factor that you are not addressing in any of your replies. I haven't seen a reply acknowledging your error.Use this data:Big dia: 0.2797mSmall dia: 0.1588mLength: 0.2286mFrequency: 1.262GHz which is very close to the 1/2 subharmonic of 2.45GHz.What is your Df?

Quote from: TheTraveller on 05/12/2015 01:33 pmQuote from: Rodal on 05/12/2015 01:26 pmQuote from: TheTraveller on 05/12/2015 01:16 pm..Again:1) I would not display non-physical negative values in a graph (in my Mathematica code, I have an IF condiitional statement to deal with them). That's a personal choice2) You have a big error in your calculation of 20452.053 design factor that you are not addressing in any of your replies. I haven't seen a reply acknowledging your error.Use this data:Big dia: 0.2797mSmall dia: 0.1588mLength: 0.2286mFrequency: 1.262GHz which is very close to the 1/2 subharmonic of 2.45GHz.What is your Df?Well those dimensions are different from the dimensions that appear next to "Flight Thruster" in your original spreadsheet and the frequency is way too low, therefore I do get these non-physical valuesShawyer Design Factor (air) 20452.052793Shawyer Design Factor (vacuum) -1329.537911I don't understand why you are displaying that non-physical case.When solving a physical problem I like to display values corresponding to physically valid cases.I would not display non-physical values. But again that is a matter of choice. So there is no need to argue about it any further, now that I understand that you are displaying non-physical values.Thank you

Quote from: TheTraveller on 05/12/2015 01:33 pmQuote from: Rodal on 05/12/2015 01:26 pmQuote from: TheTraveller on 05/12/2015 01:16 pm..Again:1) I would not display non-physical negative values in a graph (in my Mathematica code, I have an IF condiitional statement to deal with them). That's a personal choice2) You have a big error in your calculation of 20452.053 design factor that you are not addressing in any of your replies. I haven't seen a reply acknowledging your error.Use this data:Big dia: 0.2797mSmall dia: 0.1588mLength: 0.2286mFrequency: 1.262GHz which is very close to the 1/2 subharmonic of 2.45GHz.What is your Df?Well those dimensions are different from the dimensions that appear next to "Flight Thruster" in your original spreadsheet and the frequency is way too low, therefore I do get these non-physical valuesShawyer Design Factor (air) 20452.052793Shawyer Design Factor (vacuum) -1329.537911When solving a physical problem I like to display values corresponding to physically valid cases.I would not display non-physical values. But again that is a matter of choice. So there is no need to argue about it any further, now that I understand that you are displaying non-physical values.Thank you

...These are the facts as I see them:1) The Df alters with the Rf frequency and cavity configuration.2) The value of the cavity Df effects the generated Thrust. T = 2 Df Po Q / c. Therefore Rf frequency effects Thrust.3) There is a Rf frequency for every cavity configuration that will generate an infinite Df.4) Rf frequencies below that optimal frequency generate negative Dfs.5) Rf frequencies above that optimal frequency generate positive Dfs.6) All tuned / resonant circuits have a peak resonate frequency.7) High Q tuned / resonant circuits have a very sharp energy stored versus frequency curve.Speculation:1) The plots for Df versus frequency sure like what I would expect from a tuned circuit that has a very high Q being subjected to a spectrum sweep.1) Shawyer appears to operate his Flight Thruster at an Rf input frequency of 3x the optimal cavity Df frequency.2) I don't think that is coincidence.

Hi, Yesterday i received and tested a magnetron from a microwave oven. Today i received the cooper and in a couple of hours i will expect to finish the frustum, will post the results in my website, where i started to post the progress of my work live: http://www.masinaelectrica.com/emdrive-independent-test/. If i do not encounter big problems i should test the drive in 3-4 hours.Iulian

Quote from: TheTraveller on 05/12/2015 02:03 pm...These are the facts as I see them:1) The Df alters with the Rf frequency and cavity configuration.2) The value of the cavity Df effects the generated Thrust. T = 2 Df Po Q / c. Therefore Rf frequency effects Thrust.3) There is a Rf frequency for every cavity configuration that will generate an infinite Df.4) Rf frequencies below that optimal frequency generate negative Dfs.5) Rf frequencies above that optimal frequency generate positive Dfs.6) All tuned / resonant circuits have a peak resonate frequency.7) High Q tuned / resonant circuits have a very sharp energy stored versus frequency curve.Speculation:1) The plots for Df versus frequency sure like what I would expect from a tuned circuit that has a very high Q being subjected to a spectrum sweep.1) Shawyer appears to operate his Flight Thruster at an Rf input frequency of 3x the optimal cavity Df frequency.2) I don't think that is coincidence.The Design Factor is an approximate equation that Shawyer presented but that he never mathematically formally derived. It has been criticized by a large number of physicists and engineers.Shawyer's Design Factor mathematical formula contains a singularity for finite values of the geometrical dimensions and finite values of frequency. The infinite values at the singularity and the negative values are obviously non-physical: they correspond to values that cannot take place in our physical world.Hence instead of writing (for example):3) There is a Rf frequency for every cavity configuration that will generate an infinite Df.That may be misinterpreted as if it would be physically possible for this to occur, and that Shawyer's approximation is an accurate model for reality over the whole range of input variables, I would instead write that there is a finite frequency at which Shawyer's expression blows up due to a singularity in Shawyer's approximaton.As an analogy, McCulloch's expression blows up for the small diameter approaching zero. I brought this up to the attention of McCulloch and McCulloch readily admits that this is due to an approximation he made in his 1-D formula. Obviously, a pointy cone would not behave the way that McCulloch's formula would predict: that limit is a non-physical situation outside the approximation limits of McCulloch.Similarly it maybe that Shawyer's expression is an engineering approximation to certain unknown ranges of dimensions and frequencies. Clearly, very large values of Shawyer's Design Factor much exceeding 1/2 and any negative values are non-physical (as brought up by Todd, separately). It may also very well be that the singularity in Shawyer's Design Factor is due to the cut-off condition. If that is the case, how accurate it is for engineering purposes and for what range of input values, remains to be assessed.

Quote from: Iulian Berca on 05/12/2015 11:47 amHi, Yesterday i received and tested a magnetron from a microwave oven. Today i received the cooper and in a couple of hours i will expect to finish the frustum, will post the results in my website, where i started to post the progress of my work live: http://www.masinaelectrica.com/emdrive-independent-test/. If i do not encounter big problems i should test the drive in 3-4 hours.IulianFrom the thermal and A/m plots from EW, most of the resonance is happening at the big end. I would not put the magnetron in that space because the input there will probably perturb the waves. Shawyer put the input near the small end. I would put it "at" the small end, depending on wave polarization. The walls should do most of the reflecting, not the small end.Todd D.

...I know infinite values are impossible. Likewise negative Dfs. That was not the point.The point is the Df equation, applied to a variable frequency, shows there is an ideal frequency that will generate the best cavity Df. Driving the cavity with some chosen frequency, like 2.45GHZ will probably NOT make anything happen. Like trying to drive a tuned LC circuit with a frequency far away from it's resonate frequency. Waste of time. Likewise driving the cavity with the calculated best Df frequency will probably do the same thing. No thrust in the real world. What the exercise shows is that the Rf generator driving the cavity should be operating 2x or 3x the best Df cavity frequency and that Rf frequency generating system must be able to vary the driving frequency so to search for the best frequency in the real world. The spreadsheet give me a starting place and an understand the cavity best Df frequency should be 1/2 or 1/3 the applied Rf frequency.To me as an engineer starting a replication of the Flight Thruster and associated variable Rf generation system, it is very new and valuable information. This is all related to real world engineering (building actual hardware) to give the best chance of generating thrust.To assisting theory development, well it may not be of much value.

Shawyer (to my knowledge) has never provided all three geometrical dimensions of the truncated cone. Hence one of the dimensions (the diameter of the small base) has to be estimated (as per the attached file, parametrized, or estimated from images, as done by @aero and others). Since Shaywer has not provided all three dimensions, there is uncertainty as to what he actually did and why@aero had correspondence with Shawyer asking for the dimension of the small diameter, to my knowledge Shawyer cryptically answered "small base diameter chosen on the basis of the cut-off frequency" (hence still unknown how close to the cutoff wavelength was the small base diameter.

[...Dr. Rodal, keeping track of these developments, it always seems to me that you and the other active participants here are in a position of "archaeologists", trying to retrace the somewhat mysterious and obscure steps by Shawyer. Maybe I missed the relevant information somewhere down the thread, but shouldn't it be easy to acquire the needed information if Shawyer has a working drive AND supposedly has already been through a lot of what is being now recreated / retraced here (again)? It's not that he has disappeared off the planet (or has he? )...

Quote from: TheTraveller on 05/12/2015 02:52 pm...I know infinite values are impossible. Likewise negative Dfs. That was not the point.The point is the Df equation, applied to a variable frequency, shows there is an ideal frequency that will generate the best cavity Df. Driving the cavity with some chosen frequency, like 2.45GHZ will probably NOT make anything happen. Like trying to drive a tuned LC circuit with a frequency far away from it's resonate frequency. Waste of time. Likewise driving the cavity with the calculated best Df frequency will probably do the same thing. No thrust in the real world. What the exercise shows is that the Rf generator driving the cavity should be operating 2x or 3x the best Df cavity frequency and that Rf frequency generating system must be able to vary the driving frequency so to search for the best frequency in the real world. The spreadsheet give me a starting place and an understand the cavity best Df frequency should be 1/2 or 1/3 the applied Rf frequency.To me as an engineer starting a replication of the Flight Thruster and associated variable Rf generation system, it is very new and valuable information. This is all related to real world engineering (building actual hardware) to give the best chance of generating thrust.To assisting theory development, well it may not be of much value.As to why Shawyer is using a particular excitation frequency I suggest that you use your spreadsheet to check the above vs. the calculated natural frequencies and mode shapes here:http://forum.nasaspaceflight.com/index.php?action=dlattach;topic=36313.0;attach=634741(see in the slide the drawing insert detail containing the two dimensions (the diameter of the big base and the length of the truncated cone) given by Shawyer while the third dimension (the diameter of the small base) of the truncated cone is parametrized on the horizontal axis (ranging from a pointy cone to a cylinder) to ascertain its correct value)Shawyer (to my knowledge) has never provided all three geometrical dimensions of the truncated cone. Hence one of the dimensions (the diameter of the small base) has to be estimated (obtained from the inverse expression for the Design Factor -when Shawyer has provided the Design Factor, parametrized as per the attached file, or estimated from images, as done by @aero and others). Since Shaywer has not provided all three dimensions, there is uncertainty as to what he actually did and why@aero had correspondence with Shawyer asking for the dimension of the small diameter, to my recollection Shawyer cryptically answered "small base diameter chosen on the basis of the cut-off frequency" (hence still unknown how close to the cutoff wavelength was Shawyer's chosen small base diameter).

Quote from: Jared on 05/12/2015 03:53 pm[...Dr. Rodal, keeping track of these developments, it always seems to me that you and the other active participants here are in a position of "archaeologists", trying to retrace the somewhat mysterious and obscure steps by Shawyer. Maybe I missed the relevant information somewhere down the thread, but shouldn't it be easy to acquire the needed information if Shawyer has a working drive AND supposedly has already been through a lot of what is being now recreated / retraced here (again)? It's not that he has disappeared off the planet (or has he? )...Personally, more than an "archaeologist" I feel like somebody dealing with the tar-baby in Uncle Remus: The more that Br'er Rabbit fights the Tar-Baby, the more entangled he becomes. As noted @aero (hat tip to him) already made a valiant effort to obtain the geometrical data from Shawyer. It has already been pointed out that people in present e-mail communication with Shawyer as well as others doing do-it-yourself can similarly attempt to obtain such data directly from him, if so interested.

Quote from: Jared on 05/12/2015 03:53 pm[...Dr. Rodal, keeping track of these developments, it always seems to me that you and the other active participants here are in a position of "archaeologists", trying to retrace the somewhat mysterious and obscure steps by Shawyer. Maybe I missed the relevant information somewhere down the thread, but shouldn't it be easy to acquire the needed information if Shawyer has a working drive AND supposedly has already been through a lot of what is being now recreated / retraced here (again)? It's not that he has disappeared off the planet (or has he? )...Personally, more than an "archaeologist" I feel like somebody dealing with the tar-baby in Uncle Remus: The more that Br'er Rabbit fights the Tar-Baby, the more entangled he becomes.

Quote from: Rodal on 05/12/2015 04:17 pmQuote from: Jared on 05/12/2015 03:53 pm[...Dr. Rodal, keeping track of these developments, it always seems to me that you and the other active participants here are in a position of "archaeologists", trying to retrace the somewhat mysterious and obscure steps by Shawyer. Maybe I missed the relevant information somewhere down the thread, but shouldn't it be easy to acquire the needed information if Shawyer has a working drive AND supposedly has already been through a lot of what is being now recreated / retraced here (again)? It's not that he has disappeared off the planet (or has he? )...Personally, more than an "archaeologist" I feel like somebody dealing with the tar-baby in Uncle Remus: The more that Br'er Rabbit fights the Tar-Baby, the more entangled he becomes. Haha, thanks for this analogy. So let's hope all mysteries will be solved before anyone gets thrown into the Briar Patch... (pun so very much intended ).

1) I have not read it in a long long time , but as I recall Br'er Rabbit wanted to trick whoever caught him into throwing him into the Briar Patch, which is where he really wanted to be 2) I recall this better: the Ba'ku planet (in Star Trek's Briar Patch) is effectively a fountain of youth, so not a bad place to be either

...

Quote from: TheTraveller on 05/12/2015 04:34 pm...Quote from: deltaMass on 05/12/2015 03:17 am...Quote from: frobnicat on 05/12/2015 01:07 pm...Quote from: WarpTech on 05/12/2015 02:16 pm...Quote from: Notsosureofit on 05/11/2015 08:50 pm...Having dealt with such technical subjects as Br'er Rabbit, the Tar-Baby, the Briar Patch, and the Ba'ku planet, we embark now into the more mundane world of Shawyer's experimental data. Please observe the attached image of Shawyer's Demonstrator Engine Data. Please notice the huge difference between the onset of the Power signal trace (vs. time) and the Down and Up thrust force signals vs. time. Note the time (from onset to reaching the first plateau or knee of the curve) is about ~20 sec.Recall that for NASA Eagleworks tests this delay is ~2 sec (about 10 times less). QUESTION 1: What is responsible for the huge time delay in Shaywer's force signal traces? For NASA Eagleworks this delay represents about ~4*10^9 electromagnetic wave cycles. For Shawyer this represents ~33*10^9 cycles. Clearly, this huge number of cycles has nothing to do with the Quantum Vacuum, or the speed of light, or the time required for a resonant cavity to reach steady state in standing waves. Is this time delay (20 sec) due to a time delay associated with a Q-multiplier effect ? Is the time delay mainly due to the phase shift settling with time ? (due to Shawyer working with a Q multiplier setup having a Q=X times multiplier with feedback, having a phase shift narrow in frequency). (hat tip to @Notsosureofit for the explanatory hint, any misinterpretation of which is mine).QUESTION 2: What is responsible for the time delay in Shaywer's force signal traces after the power is turned off? Note: quotes used to call attention to this message in case they have quotes linked to e-mail message forum notifications.Reference: http://www.emdrive.com/IAC-08-C4-4-7.pdf

From the thermal and A/m plots from EW, most of the resonance is happening at the big end. I would not put the magnetron in that space because the input there will probably perturb the waves. Shawyer put the input near the small end. I would put it "at" the small end, depending on wave polarization. The walls should do most of the reflecting, not the small end.Todd D.