EDIT: Apparently the problem is with the way that Dropbox posts the image in a webpage: the dropbox link does not show like other links
Isn't frustum a misnomer since frustum refers to a cone, not a four-sided structure...?Is the frustum-under-test (fut) just a truncated pyramid structure? ...
...If the a frustum produces 100 mN thrust, a Giza size structure might produce thrust of 100 million Newtons.In comparison, a Saturn V First stage produces approximately 34 kN (7,648,000 lbf)If we scale up by a only a factor of 10 or 100, we have respectively thrust maximums of 100 N or 100 kN....
Not really my expertise field.............
FYIhttp://www.intelligent-aerospace.com/articles/2015/02/boeing-to-build-all-electric-propulsion-satellite-for-ses.html
Quote from: FuturePass on 02/19/2015 05:56 pm...If the a frustum produces 100 mN thrust, a Giza size structure might produce thrust of 100 million Newtons.In comparison, a Saturn V First stage produces approximately 34 kN (7,648,000 lbf)If we scale up by a only a factor of 10 or 100, we have respectively thrust maximums of 100 N or 100 kN....The thrust of the EM Drive (if it is not an artifact, and if indeed it can be used for space propulsion) it is not expected to scale geometrically. On the contrary, (as discussed previously in this thread), the larger the diameter, the lower the natural frequencies of the first few modes. A significantly larger EM Drive truncated cone would result in either very low natural frequencies for the first few modes, or if one would attempt to excite the EM Drive in the GHz range, these natural frequencies would correspond to very high mode shapes that would be bunched up together in the frequency spectrum and it would be even much more difficult to keep the EM Drive in resonance with a particular mode shape. Also, very high natural frequency mode shapes are extremely difficult to calculate accurately (even with the exact solution, and almost hopeless with the Finite Element method because of difficult issues associated with ill-conditioning in inverting the matrix for very large eigenvalues).What is envisioned (if it is not an artifact, and if indeed it can be used for space propulsion) , rather than a very large EM Drive, is to maximize the thrust of the EM Drive (perhaps using superconductivity, and/or high magnetic permeability materials for the big flat end, as well as much better, anisotropic, dielectric) and to use a number of EM Drives to achieve a large overall thrust.Unlike liquid propellant rocket engines, there are no issues of fuels and oxidizers hydraulic lines, pumps, injectors, combustion instability, ignition, hydraulic pressure, etc., associated with using a large number of EM Drives, of course, particularly if ambient temperature EM Drives are used (and superconducting low temperature solutions are avoided).
Quote from: Notsosureofit on 02/19/2015 06:47 pmFYIhttp://www.intelligent-aerospace.com/articles/2015/02/boeing-to-build-all-electric-propulsion-satellite-for-ses.htmlDoes it work by work by electrically expelling propellant (reaction mass) at high speed?http://spacenews.com/35894electric-propulsion-satellites-are-all-the-rage/
Quote from: Rodal on 02/19/2015 06:19 pm.The thrust of the EM Drive (if it is not an artifact, and if indeed it can be used for space propulsion) it is not expected to scale geometrically. On the contrary, (as discussed previously in this thread), the larger the diameter, the lower the natural frequencies of the first few modes. A significantly larger EM Drive truncated cone would result in either very low natural frequencies for the first few modes, or if one would attempt to excite the EM Drive in the GHz range, these natural frequencies would correspond to very high mode shapes that would be bunched up together in the frequency spectrum and it would be even much more difficult to keep the EM Drive in resonance with a particular mode shape. Also, very high natural frequency mode shapes are extremely difficult to calculate accurately (even with the exact solution, and almost hopeless with the Finite Element method because of difficult issues associated with ill-conditioning in inverting the matrix for very large eigenvalues).What is envisioned (if it is not an artifact, and if indeed it can be used for space propulsion) , rather than a very large EM Drive, is to maximize the thrust of the EM Drive (perhaps using superconductivity, and/or high magnetic permeability materials for the big flat end, as well as much better, anisotropic, dielectric) and to use a number of EM Drives to achieve a large overall thrust.Unlike liquid propellant rocket engines, there are no issues of fuels and oxidizers hydraulic lines, pumps, injectors, combustion instability, ignition, hydraulic pressure, etc., associated with using a large number of EM Drives, of course, particularly if ambient temperature EM Drives are used (and superconducting low temperature solutions are avoided).Hi, Just want to say that I am enjoying this thread immensely even though a lot of the science is a bit above my pay grade!If the thrust is not an artifact of the experiment, in theory what level of thrust are we expecting in the best circumstances?
.The thrust of the EM Drive (if it is not an artifact, and if indeed it can be used for space propulsion) it is not expected to scale geometrically. On the contrary, (as discussed previously in this thread), the larger the diameter, the lower the natural frequencies of the first few modes. A significantly larger EM Drive truncated cone would result in either very low natural frequencies for the first few modes, or if one would attempt to excite the EM Drive in the GHz range, these natural frequencies would correspond to very high mode shapes that would be bunched up together in the frequency spectrum and it would be even much more difficult to keep the EM Drive in resonance with a particular mode shape. Also, very high natural frequency mode shapes are extremely difficult to calculate accurately (even with the exact solution, and almost hopeless with the Finite Element method because of difficult issues associated with ill-conditioning in inverting the matrix for very large eigenvalues).What is envisioned (if it is not an artifact, and if indeed it can be used for space propulsion) , rather than a very large EM Drive, is to maximize the thrust of the EM Drive (perhaps using superconductivity, and/or high magnetic permeability materials for the big flat end, as well as much better, anisotropic, dielectric) and to use a number of EM Drives to achieve a large overall thrust.Unlike liquid propellant rocket engines, there are no issues of fuels and oxidizers hydraulic lines, pumps, injectors, combustion instability, ignition, hydraulic pressure, etc., associated with using a large number of EM Drives, of course, particularly if ambient temperature EM Drives are used (and superconducting low temperature solutions are avoided).
This is what confusing about this as some proponents of the technology talk of grand projects others speak of far more modest expectations and to the layperson that's rather confusing.
Quote from: Star One on 02/19/2015 07:08 pmThis is what confusing about this as some proponents of the technology talk of grand projects others speak of far more modest expectations and to the layperson that's rather confusing.I would think that the larger, more optimistic predictions are relying on technology that hasn't been developed yet but is in theory possible.
Quote from: TescoBag on 02/19/2015 07:12 pmQuote from: Star One on 02/19/2015 07:08 pmThis is what confusing about this as some proponents of the technology talk of grand projects others speak of far more modest expectations and to the layperson that's rather confusing.I would think that the larger, more optimistic predictions are relying on technology that hasn't been developed yet but is in theory possible.Good point. The other point of confusion is this purely a technology if it works that is only useful outside the atmosphere because of the conditions of its operation. I've read it couldn't actual get anything on its own off the ground, so it's of no use for a making a launch vehicle. We aren't going to get George Jetson getting in his flying car and nipping off to the moon.
A question... is the Q-Thruster that was being worked by EagleWorks Lab similar to the EM Drive they tested? Are them completely different things with different principles? I have the vague notion of seeing a photo of it long ago (while the main subject of the article was in fact Dr White's Warp Drive experiments) and I donīt remember it having a cone similar to Shawyer's EM Drive, so I guess they are totally different principles? I wonder if the former is still being pursued? If it is "considered" an EM Drive? Maybe Paul March can clear this up (if noone else knows the answer)?