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#1240
by
FattyLumpkin
on 14 Apr, 2016 22:53
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Now envision five frustums axially connected by waveguide... would there be a power decrease in the distal frustum or would they all eventually "load" until some sort of equilibrium were attained? or?
Beat me to it again eh Monomorphic! LOL ...Run sims for a longer time period (would your program allow for such "loading" were it to occur?)
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#1241
by
FattyLumpkin
on 14 Apr, 2016 23:05
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serve me right for not checking the whole site...check this out:
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#1242
by
aero
on 14 Apr, 2016 23:24
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Some quick sims of stacked emdrives before heading out to dinner. My dims (TE311), different size holes between frustums, and far right using square waveguide.
Try connecting the cavity via a not to wide gap around the circumference. Maybe 10% of the radius wide. Not sure how well it will couple but pretty sure that it will maintain resonance much better than a central opening.
aero
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#1243
by
A_M_Swallow
on 14 Apr, 2016 23:54
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I got an simple idea to filter/stabilize the output of a noisy magnetron:
In HF technology it is state of the art to stabilize frequencies using resonant circuits such like stripline-, dielectric- or cavity-resonators. It is possible to use a simple cylindrical cavity resonator as a kind of frequency selective filter. So the suggestion is to build a small simple to calc cavity resonator at 2.45GHz and place it inline between magnetron and antenna of the frustum. The output of this additional resonator will way more stable than the magnetron alone, if one stack two or more the effect increases. Its an effective bandpass filter.
Of course this output costs a part of the power(some dB) but its pretty easy to realize and low cost technic.
In the second pic the visual Field vector represents the E-Field.
IMHO We are not after a fixed frequency but the resonant frequency of the cavity. As the cavity changes the frequency needs to change to track it.
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#1244
by
rfmwguy
on 14 Apr, 2016 23:55
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My bad, thanks flux_capacitor...yes, Cannae is stacking low freq drives now...wow, a lot has changed since their last product unveiling. Superconductor, stacking, lower frequencies.
Now...if only we could witness the performance somehow with all these design changes. Guess we don't matter, its the potential customers that need to see proof. Perhaps that has been done.
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#1245
by
rq3
on 14 Apr, 2016 23:58
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I got an simple idea to filter/stabilize the output of a noisy magnetron:
In HF technology it is state of the art to stabilize frequencies using resonant circuits such like stripline-, dielectric- or cavity-resonators. It is possible to use a simple cylindrical cavity resonator as a kind of frequency selective filter. So the suggestion is to build a small simple to calc cavity resonator at 2.45GHz and place it inline between magnetron and antenna of the frustum. The output of this additional resonator will way more stable than the magnetron alone, if one stack two or more the effect increases. Its an effective bandpass filter.
Of course this output costs a part of the power(some dB) but its pretty easy to realize and low cost technic.
In the second pic the visual Field vector represents the E-Field.
This is a classic dispersive bandpass filter. Its output power will be a small fraction of the input. The delta is heat. Again: tune the source. Repeat: tune the source. Once more: tune the source.
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#1246
by
FattyLumpkin
on 15 Apr, 2016 01:26
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That, or as aforementioned: feed Maggie clean DC and she won't burp on you:
Image compliments of Shell
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#1247
by
SteveD
on 15 Apr, 2016 01:29
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Yes. Logically though you could think it's a lot of time and effort for Guido unless he had seen real results himself from his experiments?
Considering the current mess in the LENR field, caution would seem advisable. At the same time, the EMDrive lacks the history of failed replication attempts found with LENR.
I wonder if you could get a YBCO endplate cool enough to be superconducting using Peltier tiles or the like (cut out the entire liquid nitrogen mess). I fear that it might cost too much $$$.
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#1248
by
tchernik
on 15 Apr, 2016 01:48
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My bad, thanks flux_capacitor...yes, Cannae is stacking low freq drives now...wow, a lot has changed since their last product unveiling. Superconductor, stacking, lower frequencies.
Now...if only we could witness the performance somehow with all these design changes. Guess we don't matter, its the potential customers that need to see proof. Perhaps that has been done.
The claims aren't small, though: the site says the deep space probe could go 0.1 light years in 'bout 15 years (and to 0.5 ly in about 33 years). I'm sure any potential customers would like a very good demonstration of that.
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#1249
by
Tellmeagain
on 15 Apr, 2016 02:14
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From the site: "We recently completed successful demonstration of a 2nd generation superconducting prototype. We are planning a news release regarding our demonstration results. Cannae now has demonstrated the ability to numerically model, design, manufacture and test superconducting RF thrusters. A next generation superconducting Cannae Drive prototype is in the design phase now."
The deep space probe is interesting. Looks like they are stacking their drives.
I could not help thinking that they have the ability to numerically model, numerically design, numerically manufacture and numerically test superconducting RF thrusters. Do they mean that, seriously?
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#1250
by
rfmwguy
on 15 Apr, 2016 02:35
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From the site: "We recently completed successful demonstration of a 2nd generation superconducting prototype. We are planning a news release regarding our demonstration results. Cannae now has demonstrated the ability to numerically model, design, manufacture and test superconducting RF thrusters. A next generation superconducting Cannae Drive prototype is in the design phase now."
The deep space probe is interesting. Looks like they are stacking their drives.
I could not help thinking that they have the ability to numerically model, numerically design, numerically manufacture and numerically test superconducting RF thrusters. Do they mean that, seriously?
Think they needed to drop "numerically" altogether. Kind of a superfluous word imho.
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#1251
by
Tellmeagain
on 15 Apr, 2016 02:43
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I got an simple idea to filter/stabilize the output of a noisy magnetron:
In HF technology it is state of the art to stabilize frequencies using resonant circuits such like stripline-, dielectric- or cavity-resonators. It is possible to use a simple cylindrical cavity resonator as a kind of frequency selective filter. So the suggestion is to build a small simple to calc cavity resonator at 2.45GHz and place it inline between magnetron and antenna of the frustum. The output of this additional resonator will way more stable than the magnetron alone, if one stack two or more the effect increases. Its an effective bandpass filter.
Of course this output costs a part of the power(some dB) but its pretty easy to realize and low cost technic.
In the second pic the visual Field vector represents the E-Field.
This is a classic dispersive bandpass filter. Its output power will be a small fraction of the input. The delta is heat. Again: tune the source. Repeat: tune the source. Once more: tune the source.
I do not agree. I think X-Ray's idea has some merit. Remember that the magnetron, the filter, and the load are tightly coupled. The internal state of the magnetron will inevitably be influenced by the filter and the load, and they can't be analyzed/modeled separately. It is not like a single-direction device that your filtered-out extra energy is turned into heat. It is more like that the extra energy will not be generated in the first place.
Actually when I first saw X-ray's design, I thought of the idea that magnetron tightly coupled with a frustrum without filters as being better (close to Tajmar's design). The new one has the benefit of automatically tracking thermal expending of the frustum. X-ray's design has the problem of frequency-mismatch when the frustum and the filters are heated differently. Of course for the new one we have to determine which mode the system will lock onto.
Maybe the ultimate design is a properly shaped magnetron itself.
I am not suggestion the device I described will generate thruster. I believe it will lock into a clean oscillation though.
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#1252
by
Monomorphic
on 15 Apr, 2016 03:01
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Stacked emdrive sweep.
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#1253
by
FattyLumpkin
on 15 Apr, 2016 03:05
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Now the time to talk about REAL power sources for operation in space? Introducing the
SAFE 400 reactor. Mass 5-600 kg producing 100 kWe.
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#1254
by
SteveD
on 15 Apr, 2016 04:00
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Now the time to talk about REAL power sources for operation in space? Introducing the
SAFE 400 reactor. Mass 5-600 kg producing 100 kWe.
Is that 100kw electric or thermal? Either way dealing with the waste heat would be a major issue.
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#1255
by
Elmar Moelzer
on 15 Apr, 2016 04:28
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Now the time to talk about REAL power sources for operation in space? Introducing the
SAFE 400 reactor. Mass 5-600 kg producing 100 kWe.
Is that 100kw electric or thermal? Either way dealing with the waste heat would be a major issue.
It says kWe... So electric. I would rather go with a bigger reactor. We can build 1GW reactors with only 8,000 kg (without the cooling and turbines needed for energy generation). At least 10 kW/kg should be thinkable.
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#1256
by
FattyLumpkin
on 15 Apr, 2016 05:02
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The SAFE 400 produces 400 kW of thermal energy of which 100 kW of electric in generated by Brayton cycle (turbine). The thermal energy is transferred by the simplistic "heat pipe"... No high pressure radioactive fluids. Still can't figure out why we're not proposing a LFTR for use in space. Heat pipe tech attached.
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#1257
by
Elmar Moelzer
on 15 Apr, 2016 05:09
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You will still need cooling panels to radiate off all the heat in space. Hotter reactors are better, because (somewhat counterintuitively), more heat is easier to radiate off.
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#1258
by
X_RaY
on 15 Apr, 2016 05:30
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#1259
by
X_RaY
on 15 Apr, 2016 06:36
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I got an simple idea to filter/stabilize the output of a noisy magnetron:
In HF technology it is state of the art to stabilize frequencies using resonant circuits such like stripline-, dielectric- or cavity-resonators. It is possible to use a simple cylindrical cavity resonator as a kind of frequency selective filter. So the suggestion is to build a small simple to calc cavity resonator at 2.45GHz and place it inline between magnetron and antenna of the frustum. The output of this additional resonator will way more stable than the magnetron alone, if one stack two or more the effect increases. Its an effective bandpass filter.
Of course this output costs a part of the power(some dB) but its pretty easy to realize and low cost technic.
In the second pic the visual Field vector represents the E-Field.
This is a classic dispersive bandpass filter. Its output power will be a small fraction of the input. The delta is heat. Again: tune the source. Repeat: tune the source. Once more: tune the source.
OK this was a tip for people using a noisy magnetron as source because its cheap but not tunable in frequency.
Its less of interest what is tuned, the source frequency at fixed resonator geometry or the cavity at fixed frequency of the source(movable endplate or similar). If this done well the result is similar.
But again I am with you, If a tunable source(+amp) is available (maybe PLL control) it is much easier to tune the frequency.
BTW there are automated mechanical stub tuners available at the market.
http://www.mksinst.com/docs/UR/SmartMatch-DS.pdfA mechanical cavity tuning could be automated in the same way.
