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#840 by lmbfan on 28 Dec, 2015 16:26
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Concerning your experience with Computational Fluid Dynamics, there is a need to model some of these experiments natural convection problem. It involves low Reynolds number flow, but above the Reynolds number for the Stokes flow approximation, so a full Navier-Stokes model may be needed.
For example, rfmwguy has an experiment where he placed a naked magnetron on top of an EM Drive. The magnetron got very hot, which resulted in natural convection currents on the flat plate the magnetron was resting on, with unknown time dependence of the vortex shedding that resulted from it. The problem is more complicated because, rfmwguy turned the magnetron on and off during his experiment which interacted with the natural convection initially set by turning the magnetron on. This resulted in a complicated, low Reynolds number, transient response. The response is NOT unique: sometimes turning the magnetron ON results in a force down during his experiment and sometimes it does not. Glenfish made a valiant attempt at analyzing the response statistically, but he admitted that the statistical population of the sample population is not large enough to ascertain whether it represents the true statistical population of the (unknown transient response details of the) physics behind this experiment.
So, a computational fluid dynamics model of rfmwguy's experiment natural convection interaction with his turning the magnetron on and off would be fun to see.
What CFD computer program do you have experience with, and are you willing to take your time to model the natural convection in these experiments?
Since this is read by a wide audience, this question is really addressed at large: it would be useful for somebody to model the low Reynolds number, natural convection in these experiments with a CFD model
So fair disclosure up front: I write software for a living currently and only have a start on my M.S. in Aerospace, although I have taken a CFD class already that concentrates on both implementation and theory. I have some experience in both Ansys Fluent and OpenFoam. I would be much more comfortable doing 3D simulations in Fluent. Unfortunately, I don't currently have access to Fluent as I am sure you already know, it cost an arm and a leg. Its been over a year since I have used OpenFoam and I don't think with the current level of free time I have that I would be able to mesh the problem in 3D. If anyone wants to help model it, I'd be happy to leave it running on my computer for a week or two though as I have a fairly high end machine that would be ideal for this type of work.
Also, just on a side note, wouldn't this be rather hellish to model? It seems like having a fine mesh like rfmwguy's EMDrive would require an ultra fine grid to get near accurate results of the air interacting with the heated mesh, not to mention the difficulty of creating the model. I am sure there are tools that I am unaware of for modeling this kind of surface though.
What kind of models do you need? I made a simple IGES model of rfmwguy's magnetron housing located here:
http://forum.nasaspaceflight.com/index.php?topic=39004.msg1459224#msg1459224
I may have some free time in the next day or two to make more elaborate models, if given enough information. -
#841 by Rodal on 28 Dec, 2015 17:06
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@Dr. Rodal,
https://drive.google.com/folderview?id=0B1XizxEfB23tRm41bVFtM1pVYlU&usp=sharing
Are you finished with this data set containing 14 sets of csv files for 7 increasingly longer runs, ending with a 1 microsecond run? Runs are for the Yang-Shell 6 degree cavity model with antenna at the big end and at the small end for each run length. That is the same model that you have already post processed data for. If you are finished, or have otherwise secured the data, I would like to remove it so as to recover the Google drive space occupied by the folder. It is a significant percentage of the 15 GB of space available.
Note that the shorter run data sets should be duplicates of data that you have already post processed.
aero
I don't know whether I'm going to get the time to analyze again these data or other Meep data (if my memory is correct there is a very long run, much longer than others, that you had run that I have not had the time to analyze).
You have to be your own judge of what to keep and what to delete. The particular runs that I analyzed (for stress, force and Poynting vector field vs time) may be useful to others that may want to independently calculate stresses, forces and Poynting vector fields vs. time, and if you delete them, they may not be able to do such independent verification. -
#842 by ThereIWas3 on 28 Dec, 2015 17:31
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I am having trouble reconciling all the dimensions in SeeShell's blueprint. The waveguide is shown as being 9.97cm high and protruding from the frustrum wall by 7.6 cm at the top. The end of the waveguide is given as 17.79cm from the central axis. This means that the point where the top of the waveguide meets the frustrum is 17.79 - 7.6 = 10.19 cm from the axis. The large end diameter is 29.5cm, so bigR = 14.75cm. Thus the slope of the wall is
atan((14.75 - 10.19) / 9.97) = atan( 4.56 / 9.97) = atan( .457 ) = 24.56 degrees.
But the frustrum itself is described as Height 24.79cm, smallD = 17cm, smallR = 8.5cm, for a slope ofatan( (14.75-8.5) / 24.79 ) = atan( 6.25 / 24.79 ) = atan( .252 ) = 14.15 degrees
Something is inconsistent. I notice the blueprint does not show the dimensions for height or small end diameter, so perhaps the numbers I am using for that, from an earlier post, are obsolete. -
#843 by rfmwguy on 28 Dec, 2015 17:44
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Thanks so much for doing the model. I hope someone here provides you more info. Dimensional is all I have plus temp. Perhaps @Rodal can help since he is wanting this type of data. Here is the video that shows the magnetron ignited:
Concerning your experience with Computational Fluid Dynamics, there is a need to model some of these experiments natural convection problem. It involves low Reynolds number flow, but above the Reynolds number for the Stokes flow approximation, so a full Navier-Stokes model may be needed.
For example, rfmwguy has an experiment where he placed a naked magnetron on top of an EM Drive. The magnetron got very hot, which resulted in natural convection currents on the flat plate the magnetron was resting on, with unknown time dependence of the vortex shedding that resulted from it. The problem is more complicated because, rfmwguy turned the magnetron on and off during his experiment which interacted with the natural convection initially set by turning the magnetron on. This resulted in a complicated, low Reynolds number, transient response. The response is NOT unique: sometimes turning the magnetron ON results in a force down during his experiment and sometimes it does not. Glenfish made a valiant attempt at analyzing the response statistically, but he admitted that the statistical population of the sample population is not large enough to ascertain whether it represents the true statistical population of the (unknown transient response details of the) physics behind this experiment.
So, a computational fluid dynamics model of rfmwguy's experiment natural convection interaction with his turning the magnetron on and off would be fun to see.
What CFD computer program do you have experience with, and are you willing to take your time to model the natural convection in these experiments?
Since this is read by a wide audience, this question is really addressed at large: it would be useful for somebody to model the low Reynolds number, natural convection in these experiments with a CFD model
So fair disclosure up front: I write software for a living currently and only have a start on my M.S. in Aerospace, although I have taken a CFD class already that concentrates on both implementation and theory. I have some experience in both Ansys Fluent and OpenFoam. I would be much more comfortable doing 3D simulations in Fluent. Unfortunately, I don't currently have access to Fluent as I am sure you already know, it cost an arm and a leg. Its been over a year since I have used OpenFoam and I don't think with the current level of free time I have that I would be able to mesh the problem in 3D. If anyone wants to help model it, I'd be happy to leave it running on my computer for a week or two though as I have a fairly high end machine that would be ideal for this type of work.
Also, just on a side note, wouldn't this be rather hellish to model? It seems like having a fine mesh like rfmwguy's EMDrive would require an ultra fine grid to get near accurate results of the air interacting with the heated mesh, not to mention the difficulty of creating the model. I am sure there are tools that I am unaware of for modeling this kind of surface though.
What kind of models do you need? I made a simple IGES model of rfmwguy's magnetron housing located here:
http://forum.nasaspaceflight.com/index.php?topic=39004.msg1459224#msg1459224
I may have some free time in the next day or two to make more elaborate models, if given enough information.
(edit) Also added pic of 12x12 inch top plate. Note it reflects the magnetron, but its own temperature is nominal. Not a high likelihood the top plate is contributing much to lift as some have suggested.
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#844 by Rodal on 28 Dec, 2015 17:48
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Thanks so much for doing the model. I hope someone here provides you more info. Dimensional is all I need. Perhaps @Rodal can help since he is wanting this type of data. Here is the video that shows the magnetron ignited:
Concerning your experience with Computational Fluid Dynamics, there is a need to model some of these experiments natural convection problem. It involves low Reynolds number flow, but above the Reynolds number for the Stokes flow approximation, so a full Navier-Stokes model may be needed.
For example, rfmwguy has an experiment where he placed a naked magnetron on top of an EM Drive. The magnetron got very hot, which resulted in natural convection currents on the flat plate the magnetron was resting on, with unknown time dependence of the vortex shedding that resulted from it. The problem is more complicated because, rfmwguy turned the magnetron on and off during his experiment which interacted with the natural convection initially set by turning the magnetron on. This resulted in a complicated, low Reynolds number, transient response. The response is NOT unique: sometimes turning the magnetron ON results in a force down during his experiment and sometimes it does not. Glenfish made a valiant attempt at analyzing the response statistically, but he admitted that the statistical population of the sample population is not large enough to ascertain whether it represents the true statistical population of the (unknown transient response details of the) physics behind this experiment.
So, a computational fluid dynamics model of rfmwguy's experiment natural convection interaction with his turning the magnetron on and off would be fun to see.
What CFD computer program do you have experience with, and are you willing to take your time to model the natural convection in these experiments?
Since this is read by a wide audience, this question is really addressed at large: it would be useful for somebody to model the low Reynolds number, natural convection in these experiments with a CFD model
So fair disclosure up front: I write software for a living currently and only have a start on my M.S. in Aerospace, although I have taken a CFD class already that concentrates on both implementation and theory. I have some experience in both Ansys Fluent and OpenFoam. I would be much more comfortable doing 3D simulations in Fluent. Unfortunately, I don't currently have access to Fluent as I am sure you already know, it cost an arm and a leg. Its been over a year since I have used OpenFoam and I don't think with the current level of free time I have that I would be able to mesh the problem in 3D. If anyone wants to help model it, I'd be happy to leave it running on my computer for a week or two though as I have a fairly high end machine that would be ideal for this type of work.
Also, just on a side note, wouldn't this be rather hellish to model? It seems like having a fine mesh like rfmwguy's EMDrive would require an ultra fine grid to get near accurate results of the air interacting with the heated mesh, not to mention the difficulty of creating the model. I am sure there are tools that I am unaware of for modeling this kind of surface though.
What kind of models do you need? I made a simple IGES model of rfmwguy's magnetron housing located here:
http://forum.nasaspaceflight.com/index.php?topic=39004.msg1459224#msg1459224
I may have some free time in the next day or two to make more elaborate models, if given enough information.
...
See this message regarding Computational Fluid Dynamics (CD+FD) vis-a-vis rfmwguy's experiment:
https://forum.nasaspaceflight.com/index.php?topic=39004.msg1465399#msg1465399
There may be some confusion in rfmwguy's response (unless I am missing something):
1) The message deals only with a simple IGES model of rfmwguy's magnetron housing, not with a CFD analysis
2) The dimensions needed for rfmwguy's experiment must be given by rfmwguy since rfmwguy is the one that run the experiment. I don't understand on what basis rfmwguy writes << I hope someone here provides you more info. Dimensional is all I need.>>
3) The issues involved with doing a CFD analysis, as previously discussed, have to do with computational resources. Since even Meep models are presently run to only 0.01 microseconds because of lack of computational speed, and since as previously discussed a CFD transient 3D analysis with a full Navier-Stokes solution would make children's play of the Meep analysis. Compound that by the fact that a CFD analysis with the Navier Stokes equation would be nonlinear and hence much more demanding to formulate properly and to interpret properly. -
#845 by Rodal on 28 Dec, 2015 18:03
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Not exactly what has been stated. The fluid dynamics of your experiment are such that as your EM Drive experiences an initial lift force (due to buoyancy of the magnetron as it gets heated and by the air molecules on the outside surface moving up), the top rectangular plate is involved in initial drag forces (and yes, it is also eventually involved in lift as enough air convects in natural convection). As there is vortex shedding, and the EM Drive moves up, there is air rushing below the rectangular plate. Lift and drag are involved together in such a problem in a transient time-dependent way made more complicated by turning the magnetron on and off during your experiment. You have to understand the drag forces (in addition to the lift forces) vs time in order to interpret the results of your experiment.
(edit) Also added pic of 12x12 inch top plate. Note it reflects the magnetron, but its own temperature is nominal. Not a high likelihood the top plate is contributing much to lift as some have suggested.
You cannot ignore the effect of the rectangular plate in the motion of the EM Drive in your experiment. -
#846 by rfmwguy on 28 Dec, 2015 18:06
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2 new DIY Emdrive Videos (Korean - edited):
(symmetrical cavity)
(non-symmetrical cavity - I think?) -
#847 by rfmwguy on 28 Dec, 2015 18:11
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I would be quite helpful to put the words into numbers if you have the experience. Thanks in advance....
Not exactly what has been stated. The fluid dynamics of your experiment are such that as your EM Drive experiences an initial lift force (due to buoyancy of the magnetron as it gets heated and by the air molecules on the outside surface moving up), the top rectangular plate is involved in initial drag forces (and yes, it is also eventually involved in lift as enough air convects in natural convection). As there is vortex shedding, and the EM Drive moves up, there is air rushing below the rectangular plate. Lift and drag are involved together in such a problem in a transient time-dependent way made more complicated by turning the magnetron on and off during your experiment. You have to understand the drag forces (in addition to the lift forces) vs time in order to interpret the results of your experiment.
(edit) Also added pic of 12x12 inch top plate. Note it reflects the magnetron, but its own temperature is nominal. Not a high likelihood the top plate is contributing much to lift as some have suggested.
You cannot ignore the effect of the rectangular plate in the motion of the EM Drive in your experiment. -
#848 by Rodal on 28 Dec, 2015 18:15
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Unless you have the necessary computer resources (*) available to run an ANSYS/Fluent model (for example) the best approach is to completely remove the magnetron from the exterior surface of the EM Drive on your experiment as done by Shell, and to address the remaining smaller natural convection forces as previously discussed (for example by comparison with a heated EM Drive that is not excited by RF).
I would be quite helpful to put the words into numbers if you have the experience. Thanks in advance....
Not exactly what has been stated. The fluid dynamics of your experiment are such that as your EM Drive experiences an initial lift force (due to buoyancy of the magnetron as it gets heated and by the air molecules on the outside surface moving up), the top rectangular plate is involved in initial drag forces (and yes, it is also eventually involved in lift as enough air convects in natural convection). As there is vortex shedding, and the EM Drive moves up, there is air rushing below the rectangular plate. Lift and drag are involved together in such a problem in a transient time-dependent way made more complicated by turning the magnetron on and off during your experiment. You have to understand the drag forces (in addition to the lift forces) vs time in order to interpret the results of your experiment.
(edit) Also added pic of 12x12 inch top plate. Note it reflects the magnetron, but its own temperature is nominal. Not a high likelihood the top plate is contributing much to lift as some have suggested.
You cannot ignore the effect of the rectangular plate in the motion of the EM Drive in your experiment.
____
(*) and even if such resources where available, the point is made that the better experiment is the one where the magnetron is not running naked on top of the EM Drive, as analyzing such a CFD model would be a project in itself and unnecessarily complicates the experiment, as the behavior of such natural convection small forces are known to be somewhat chaotic, with respect to the small forces vs time involved -
#849 by rfmwguy on 28 Dec, 2015 18:45
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I have to (humbly) disagree here, which is no problem, but I believe randomized air turbulence cannot account for significant reaction/recoil against a rather strong lifting force unless there is an outgassing component, which was not present with mesh or within the magnetron itself. There is only ambient air. The magnetron is a closed system.
Unless you have the necessary computer resources (*) available to run an ANSYS/Fluent model the best approach is to completely remove the magnetron from the exterior surface of the EM Drive on your experiment as done by Shell, and to address the remaining smaller natural convection forces as previously discussed (for example by comparison with a heated EM Drive that is not excited by RF).
I would be quite helpful to put the words into numbers if you have the experience. Thanks in advance....
(...)You cannot ignore the effect of the rectangular plate in the motion of the EM Drive in your experiment.
(edit) Also added pic of 12x12 inch top plate. Note it reflects the magnetron, but its own temperature is nominal. Not a high likelihood the top plate is contributing much to lift as some have suggested.
____
(*) and even if such resources where available, the point is made that the better experiment is the one where the magnetron is not running naked on top of the EM Drive, as analyzing such a CFD model would be a project in itself and unnecessarily complicates the experiment, as the behavior of such natural convection small forces are known to be somewhat chaotic, with respect to the small forces vs time involved
I dwell on this because a heat source, once turned on, would naturally begin to lift and not sink as long as there were no fuel/gases/propellant released (action-reaction sort of thing). Can you demonstrate or point to a study in fluid dynamics that runs counter to my belief that there is negligible reaction/recoil against thermal lift once a heat source is turned on and zero propellant was used?
Reason I am sticking to my guns on this (until proven wrong) is #1. I don't believe there is a significant thermal recoil. #2. A mechanical redesign of the RF source requires a lot more of an investment and mechanically "complicates" the experiment with more variables (making it inherently different from my Phase I observations). -
#850 by Chrochne on 28 Dec, 2015 18:56
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2 new DIY Emdrive Videos (Chinese):
(symmetrical cavity)
(non-symmetrical cavity - I think?)
Unless I am wrong the kanji (symbols) are korean not chinese. I am student of japanese language and I know chinese kanji looks different. -
#851 by Rodal on 28 Dec, 2015 19:05
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I have to (humbly) disagree here, which is no problem, but I believe randomized air turbulence cannot account for significant reaction/recoil against a rather strong lifting force unless there is an outgassing component, which was not present with mesh or within the magnetron itself. There is only ambient air. The magnetron is a closed system.
Unless you have the necessary computer resources (*) available to run an ANSYS/Fluent model the best approach is to completely remove the magnetron from the exterior surface of the EM Drive on your experiment as done by Shell, and to address the remaining smaller natural convection forces as previously discussed (for example by comparison with a heated EM Drive that is not excited by RF).
I would be quite helpful to put the words into numbers if you have the experience. Thanks in advance....
(...)You cannot ignore the effect of the rectangular plate in the motion of the EM Drive in your experiment.
(edit) Also added pic of 12x12 inch top plate. Note it reflects the magnetron, but its own temperature is nominal. Not a high likelihood the top plate is contributing much to lift as some have suggested.
____
(*) and even if such resources where available, the point is made that the better experiment is the one where the magnetron is not running naked on top of the EM Drive, as analyzing such a CFD model would be a project in itself and unnecessarily complicates the experiment, as the behavior of such natural convection small forces are known to be somewhat chaotic, with respect to the small forces vs time involved
I dwell on this because a heat source, once turned on, would naturally begin to lift and not sink as long as there were no fuel/gases/propellant released (action-reaction sort of thing). Can you demonstrate or point to a study in fluid dynamics that runs counter to my belief that there is negligible reaction/recoil against thermal lift once a heat source is turned on and zero propellant was used?
Reason I am sticking to my guns on this (until proven wrong) is #1. I don't believe there is a significant thermal recoil. #2. A mechanical redesign of the RF source requires a lot more of an investment and mechanically "complicates" the experiment with more variables (making it inherently different from my Phase I observations).
Your experimental results do not show a unique reaction against turning on the magnetron, on the contrary, there are times at which the magnetron is turned on and there is no such reaction force. You don't have a motion down that was produced to a predicted amount every time that you commanded. That's why you resorted to a statistical analysis.
Glenfish accepted that your sample population is not large enough to arrive at a statistical conclusion because your sample population cannot be shown to statistically represent the true statistical population (particularly for a problem whose natural convection forces vs time are not being modeled).
This time dependent motion down may be due to the transient natural convection due to the drag forces from the square plate and from the vortex shedding interacting with the magnetron being turned on and off, all interacting with the dynamics of your weighted pendulum .
There is no robust basis to disagree on anyway because we don't have an analysis of the natural convection lift and drag forces vs. time, and nobody has run a CFD analysis -nor will it be practical to run that analysis-. It is your experience with such problems vs. my experience on how we interpret your experimental results. Let's agree that neither of us are going to convince other people, just based on our subjective assessments.
Concerning <<Can you demonstrate or point to a study in fluid dynamics that runs counter to my belief that there is negligible reaction/recoil against thermal lift once a heat source is turned on and zero propellant was used?>> any natural convection problem involving a heated object (being turned on and off) on top of a square plate, in a balance will experience non-monotic lift vs time: it will involve momentary motions down (as well as up). Frobnicat also gave examples of what could produce such motions.
I find your interpretation of the erratic motion down (that sometimes correlates with the magnetron and sometimes it does NOT) as being due to an anomalous EM Drive force as unconvincing.
Again, we disagree on an interpretation of your experiment and to me it is evident that <<the best approach is to completely remove the magnetron from the exterior surface of the EM Drive on your experiment as done by Shell, and to address the remaining smaller natural convection forces as previously discussed (for example by comparison with a heated EM Drive that is not excited by RF).>>
Actually, as the proponents of the EM Drive propose that it is useful for spaceflght, such experiments would be best conducted in a partial vacuum and hence completely eliminate this controversy
Another interesting alternative is TheTraveller's proposed rotary rig where he is predicting that it will accelerate continuously under a given Input Power
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#852 by RonM on 28 Dec, 2015 19:29
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2 new DIY Emdrive Videos (Chinese):
(symmetrical cavity)
(non-symmetrical cavity - I think?)
Unless I am wrong the kanji (symbols) are korean not chinese. I am student of japanese language and I know chinese kanji looks different.
Yes, those are Hangul (Korean alphabet). Each symbol is a group of letters indicating a syllable. An elegant form of writing.
https://en.wikipedia.org/wiki/Hangul -
#853 by aero on 28 Dec, 2015 19:39
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I am having trouble reconciling all the dimensions in SeeShell's blueprint. The waveguide is shown as being 9.97cm high and protruding from the frustrum wall by 7.6 cm at the top. The end of the waveguide is given as 17.79cm from the central axis. This means that the point where the top of the waveguide meets the frustrum is 17.79 - 7.6 = 10.19 cm from the axis. The large end diameter is 29.5cm, so bigR = 14.75cm. Thus the slope of the wall is
atan((14.75 - 10.19) / 9.97) = atan( 4.56 / 9.97) = atan( .457 ) = 24.56 degrees.
But the frustrum itself is described as Height 24.79cm, smallD = 17cm, smallR = 8.5cm, for a slope ofatan( (14.75-8.5) / 24.79 ) = atan( 6.25 / 24.79 ) = atan( .252 ) = 14.15 degrees
Something is inconsistent. I notice the blueprint does not show the dimensions for height or small end diameter, so perhaps the numbers I am using for that, from an earlier post, are obsolete.
What are the dimensions used in aero's Meep model of Shell's fustrum of a cone?
and how do they compare with the above dimensions?
My approach is somewhat different, using only the radius of the frustum at the top of the wave guide. I calculate that using the slope of the cone wall.
slope = (bigrad - smallrad)/height.
WGtoprad = bigrad - WGheight * slope
I also correct for lateral curvature of the cone to close gaps at the top corners, which in reality just cuts through the remainder of the skin at the top corner as I use a thick skin model. With the frustum radius at the top inside of the wave guide, place the back plane 0.076 m more distant add skin thickness all around and place a material block of the correct wave guide dimensions. Finally, cut the inside with an air block and shave the inside as ThereIWas3 does by completing the frustum with an internal air frustum.
That gives 0.1963594294 m between the wave guide back plane and the central axis.
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#854 by rfmwguy on 28 Dec, 2015 19:45
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Thanks! Appreciate the info...Hey, Korea...a new Country for DIY!2 new DIY Emdrive Videos (Chinese):
(symmetrical cavity)
(non-symmetrical cavity - I think?)
Unless I am wrong the kanji (symbols) are korean not chinese. I am student of japanese language and I know chinese kanji looks different.
Yes, those are Hangul (Korean alphabet). Each symbol is a group of letters indicating a syllable. An elegant form of writing.
https://en.wikipedia.org/wiki/Hangul -
#855 by Chrochne on 28 Dec, 2015 20:04
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Thanks! Appreciate the info...Hey, Korea...a new Country for DIY!2 new DIY Emdrive Videos (Chinese):
(symmetrical cavity)
(non-symmetrical cavity - I think?)
Unless I am wrong the kanji (symbols) are korean not chinese. I am student of japanese language and I know chinese kanji looks different.
Yes, those are Hangul (Korean alphabet). Each symbol is a group of letters indicating a syllable. An elegant form of writing.
https://en.wikipedia.org/wiki/Hangul
Do you have any more information?
Is this a DIY experiment ?
Is it done at a University?
Are there experimental reports?
실험 - stands for "Experiment" so we know he conducts EmDrive Experiment or test. Lets look for his name...
alright I found something - but its whole in korean - I do not understand a word there, but from pictures you can cleary see that it is whole about EmDrive.
http://m.blog.daum.net/smileru/8888521
- Yes world definitely took notice of EmDrive and DIY are popping all around the world.
Now what we need is to contact those isolated groups of testers and get them here.
I will be digging a bit more and will try to report on what I will find
Modification: I think this is the guys web. I found this site using his YouTube name, but it is only my guess. -
#856 by RonM on 28 Dec, 2015 20:12
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alright I found something - but its whole in korean - I do not understand a word there, but from pictures you can cleary see that it is whole about EmDrive.
If you are using Chrome, you can right click on the site and select translate. Google Translate will fix it up for you. Of course, depending on how different the language is from your own, you still might not be able to understand it. Computer based translation has a long way to go.
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#857 by Chrochne on 28 Dec, 2015 20:18
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Thanks! Appreciate the info...Hey, Korea...a new Country for DIY!2 new DIY Emdrive Videos (Chinese):
(symmetrical cavity)
(non-symmetrical cavity - I think?)
Unless I am wrong the kanji (symbols) are korean not chinese. I am student of japanese language and I know chinese kanji looks different.
Yes, those are Hangul (Korean alphabet). Each symbol is a group of letters indicating a syllable. An elegant form of writing.
https://en.wikipedia.org/wiki/Hangul
Do you have any more information?
Is this a DIY experiment ?
Is it done at a University?
Are there experimental reports?
실험 - stands for "Experiment" so we know he conducts EmDrive Experiment or test. Lets look for his name...
alright I found something - but its whole in korean - I do not understand a word there, but from pictures you can cleary see that it is whole about EmDrive.
http://m.blog.daum.net/smileru/8888521
- Yes world definitely took notice of EmDrive and DIY are popping all around the world.
Now what we need is to contact those isolated groups of testers and get them here.
I will be digging a bit more and will try to report on what I will find
Modification: I think this is the guys web. I found this site using his YouTube name, but it is only my guess.
Alright I just wrote to the guy on YouTube. He seems to check regulary and I told him to check the NSF forum, that we took notice of his experiments and would like him to join us here and tell us about his experiment. -
#858 by ThereIWas3 on 28 Dec, 2015 20:19
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What are the dimensions used in aero's Meep model of Shell's fustrum of a cone?
and how do they compare with the above dimensions?
I am more interested in what dimensions Shell is actually using in her device, The numbers I have, all directly from her, are inconsistent, so there is a mistake somewhere.
My model has no edge gaps in it, because I model the entire frustrum as a single hollow piece of copper.
I detected the problem as I was trying to get my 3D openSCAD model to look like her blueprint, regarding the placement of antennas, and could not get it to look like her drawing, using her dimensions. -
#859 by rfmwguy on 28 Dec, 2015 20:27
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(my Mod hat is off)
(...)
Unless you have the necessary computer resources (*) available to run an ANSYS/Fluent model the best approach is to completely remove the magnetron from the exterior surface of the EM Drive on your experiment as done by Shell, and to address the remaining smaller natural convection forces as previously discussed (for example by comparison with a heated EM Drive that is not excited by RF).
I would be quite helpful to put the words into numbers if you have the experience. Thanks in advance....
(...)You cannot ignore the effect of the rectangular plate in the motion of the EM Drive in your experiment.
(edit) Also added pic of 12x12 inch top plate. Note it reflects the magnetron, but its own temperature is nominal. Not a high likelihood the top plate is contributing much to lift as some have suggested.
____
(*) and even if such resources where available, the point is made that the better experiment is the one where the magnetron is not running naked on top of the EM Drive, as analyzing such a CFD model would be a project in itself and unnecessarily complicates the experiment, as the behavior of such natural convection small forces are known to be somewhat chaotic, with respect to the small forces vs time involved
Your experimental results do not show a unique reaction against turning on the magnetron, on the contrary, there are times at which the magnetron is turned on and there is no such reaction force. You don't have a motion down that was produced to a predicted amount every time that you commanded. That's why you resorted to a statistical analysis.
Glenfish accepted that your sample population is not large enough to arrive at a statistical conclusion because your sample population cannot be shown to statistically represent the true statistical population (particularly for a problem whose natural convection forces vs time are not being modeled).
This will be my last public posting on this issue, but you've made public comments regarding my Phase I observations and so will I:
I find your assessment a bit perplexing since you had been away for so long and had no commentary during my experiment as it was being conducted...only well after the fact and it was very subjective/declarative. I accept specific quantifiable critique, not "generalized". This, of course, is a big problem on other forums and not usually here.
"That's why you resorted to a statistical analysis."
This is another problem...I did not seek/resort to Glenn's assistance. He volunteered it when other's like yourself fell silent. In fact, several others helped when I was struggling with the Laser-spot analysis. Other people here stepped up THEN, not weeks later with hindsight commentary.
So, to summarize, I do not agree with your belated assessment, mainly because you have no specific critique, but generalized statements such as "there are times at which the magnetron is turned on and there is no such reaction force". What about the majority of the time when something was noted?
Glenn has the statistical analysis which I don't believe you can dismiss off hand. Rather than take up bandwidth here, please PM him to sort things out. I only ask one thing:
Whether accidently or by intent, you have given people the impression that my Phase I observational tests were null. I do not agree with that, both from what I personally witnessed with my own eyes (ala Shell) and more importantly, what Glenn relayed to me thru statistical analysis. Check out my FT2B video where the "aha" moment was and compare that to FT1, FT2 and FT2A where there was none.
Look, if we don't have the computing power to do your fluid dynamics analysis...so be it, don't even bring it up. I happen to believe that lift can be predicted and accounted for statistically and there is no phantom downwards "turbulence" that must be accounted for. Did I have an ideal experiment? No. Did I do things simply and within a small budget? Yes.
Got that off my chest, now back to mod-mode.