I don't understand why perforated copper sheets instead of solid. At that frequency it will decrease the effective conductivity and ruin the Q of any cavity. Additionally you lose structural rigidity and will be suspect to thermal effects changing the shape of the cavity (having a variable Q).
Quote from: rfcavity on 07/14/2015 07:48 pmI don't understand why perforated copper sheets instead of solid. At that frequency it will decrease the effective conductivity and ruin the Q of any cavity. Additionally you lose structural rigidity and will be suspect to thermal effects changing the shape of the cavity (having a variable Q).The idea with perforations was to eliminate the possibility that the cavity could be working as a hot-air balloon. A perforated cavity reduces hot air as an error factor significantly.(Reduces, not eliminates.)
...I don't understand why perforated copper sheets instead of solid. At that frequency it will decrease the effective conductivity and ruin the Q of any cavity. Additionally you lose structural rigidity and will be suspect to thermal effects changing the shape of the cavity (having a variable Q).
If the emdrive functions as you think it may, and deltamass' statement about the air (acting as a necessary medium) absorbing the apparent violations of CoM is correct, would allowing air to escape mask the fact that air is effectively acting as reaction mass?Again, my apologies if I'm misunderstanding somewhere.
Quote from: ElizabethGreene on 07/14/2015 08:03 pmQuote from: rfcavity on 07/14/2015 07:48 pmI don't understand why perforated copper sheets instead of solid. At that frequency it will decrease the effective conductivity and ruin the Q of any cavity. Additionally you lose structural rigidity and will be suspect to thermal effects changing the shape of the cavity (having a variable Q).The idea with perforations was to eliminate the possibility that the cavity could be working as a hot-air balloon. A perforated cavity reduces hot air as an error factor significantly.(Reduces, not eliminates.) If the emdrive functions as you think it may, and deltamass' statement about the air (acting as a necessary medium) absorbing the apparent violations of CoM is correct, would allowing air to escape mask the fact that air is effectively acting as reaction mass?Again, my apologies if I'm misunderstanding somewhere.
Quote from: ElizabethGreene on 07/14/2015 08:03 pmQuote from: rfcavity on 07/14/2015 07:48 pmI don't understand why perforated copper sheets instead of solid. At that frequency it will decrease the effective conductivity and ruin the Q of any cavity. Additionally you lose structural rigidity and will be suspect to thermal effects changing the shape of the cavity (having a variable Q).The idea with perforations was to eliminate the possibility that the cavity could be working as a hot-air balloon. A perforated cavity reduces hot air as an error factor significantly.(Reduces, not eliminates.) Then you make some small venting areas. Making the whole thing out of it can have really weird side effects (even if all the holes are much smaller than a wavelength).Check out application of a perforated metal sheet at this frequency (2.45 GHz)http://repository.upenn.edu/cgi/viewcontent.cgi?article=1614&context=ese_papers
MWVP thanks for posting this!!!! Is there a slide out there with a Bottom Radius 431.8mm and height 711.2mm?!?!? Looking at this slide you can see that the 431.8mm x 711.2mm is probably not designed for the 2.4GHz frequency... and you can see that the TM010 design is the one that achieves resonance at the lowest frequency - I think March is going TM010 to allow a commercial L-band magnetron to achieve resonance.
"Hard" vacuum is relative. To get to 1-10 millitorr, PTFE gaskets and a standard rotary pump will do.To get far below that, you start needing to use polished steel, all-metal gaskets, turbomolecular or oil-diffusion pumps backed with a rotary pump, etcetera. What was the pressure of the "hard vacuum" tests by NASA?
Quote from: aero on 07/14/2015 04:04 amQuote from: Rodal on 07/14/2015 03:54 amQuote from: WarpTech on 07/14/2015 03:51 amQuote from: SeeShells on 07/14/2015 03:24 amDon't have the software to do the integration on the images but I did the large end.I hope you have good solder joints people! The maximum stress seems to ride the seem of the large end. Hence, the use of bolts, not solder to hold it together. Hmmm...It makes sense though, that when the mode energy reaches the big end, it has already expanded. So after that, most of the reflections must be concentrated around the perimeter of the big end. That's why I want to see a simulation of it turned off. I want to see how far back up the frustum the wave goes after it is reflected from the big end, and for how long.ToddIt is a location NEAR the big end, but NOT at the big end. I still have to plot the stresses at the big and at the small endsIn order to do that, don't you need csv files at the big and small ends? If so, tell me where they are. That is, what rows of the xz or xy csv files that you have correspond to the big and small ends? Then I can cut x slices at those rows and make the right csv files.aero, I figured out exactly where the bases are located in the RFMWGUY latest model that has245 FD nodes in the longitudinal x direction261 FD nodes in the transverse y and z directionsBIG BASE is at x = 16 (column 16 of 245 columns)SMALL BASE is at x = 231 (column 231 of 245 columns) (x corresponds to the column number in the matrix)So, I would need TS013 to TS13 for at x = 16 and at x = 231It is very important to get the exact location, as x=15 and x = 232 have zero fields.If you decide to locate the cross sections based on the middle node located at:x = (245-1)/2 + 1 = 123thenBIG BASE x = 16 corresponds to 123 - 107 SMALL BASE x = 231 corresponds to 123 + 108In other words, the bases are NOT equidistant from the middle node. The big base is closer by one node to the middle node than the small base
Quote from: Rodal on 07/14/2015 03:54 amQuote from: WarpTech on 07/14/2015 03:51 amQuote from: SeeShells on 07/14/2015 03:24 amDon't have the software to do the integration on the images but I did the large end.I hope you have good solder joints people! The maximum stress seems to ride the seem of the large end. Hence, the use of bolts, not solder to hold it together. Hmmm...It makes sense though, that when the mode energy reaches the big end, it has already expanded. So after that, most of the reflections must be concentrated around the perimeter of the big end. That's why I want to see a simulation of it turned off. I want to see how far back up the frustum the wave goes after it is reflected from the big end, and for how long.ToddIt is a location NEAR the big end, but NOT at the big end. I still have to plot the stresses at the big and at the small endsIn order to do that, don't you need csv files at the big and small ends? If so, tell me where they are. That is, what rows of the xz or xy csv files that you have correspond to the big and small ends? Then I can cut x slices at those rows and make the right csv files.
Quote from: WarpTech on 07/14/2015 03:51 amQuote from: SeeShells on 07/14/2015 03:24 amDon't have the software to do the integration on the images but I did the large end.I hope you have good solder joints people! The maximum stress seems to ride the seem of the large end. Hence, the use of bolts, not solder to hold it together. Hmmm...It makes sense though, that when the mode energy reaches the big end, it has already expanded. So after that, most of the reflections must be concentrated around the perimeter of the big end. That's why I want to see a simulation of it turned off. I want to see how far back up the frustum the wave goes after it is reflected from the big end, and for how long.ToddIt is a location NEAR the big end, but NOT at the big end. I still have to plot the stresses at the big and at the small ends
Quote from: SeeShells on 07/14/2015 03:24 amDon't have the software to do the integration on the images but I did the large end.I hope you have good solder joints people! The maximum stress seems to ride the seem of the large end. Hence, the use of bolts, not solder to hold it together. Hmmm...It makes sense though, that when the mode energy reaches the big end, it has already expanded. So after that, most of the reflections must be concentrated around the perimeter of the big end. That's why I want to see a simulation of it turned off. I want to see how far back up the frustum the wave goes after it is reflected from the big end, and for how long.Todd
Don't have the software to do the integration on the images but I did the large end.
@leomillertI think you're fine - looks like you have a good meep install.Yes, all of the numbers in your csv file were different than the numbers in my csv file, the not by much. I loaded both csv files into a spread sheep program then subtracted one from the other, entry by entry. Then I looked for the largest positive difference and the absolute value of the largest negative difference. I came up with 4.16333634234434E-017 and 2.7972416050126E-017. That is the difference in numerical precision of our two machines, nothing more.You're good to go, and for all you theorists out there, leomillert is now set to generate meep data for you.and leomillert, here are some links to manuals that you may wish to bookmark if you haven't already.http://www.gnu.org/software/mit-scheme/documentation/mit-scheme-user.pdfhttp://www.gnu.org/software/mit-scheme/documentation/mit-scheme-ref.pdfhttps://www.mail-archive.com/[email protected]/ - You may need to join.http://ab-initio.mit.edu/wiki/index.php/Meep_Tutorialhttp://ab-initio.mit.edu/wiki/index.php/Meep_Referencehttp://ab-initio.mit.edu/h5utils/h5topng-man.htmlhttp://ab-initio.mit.edu/h5utils/h5totxt-man.htmlhttp://www.hdfgroup.org/products/java/hdfview/UsersGuide/index.htmland don't forget, Google is your friend.aero
Is there someone who explain me the following?I don't understand in Dr White's theory of virtual electrons and positrons:This particles are real after creation (for a really short time, not an infinite) and are able to interact with the copper at the large diameter. If a created positron for example interacts with a electron inside the copper it'll annihilate and erased, at the same time a photon will radiate from the annihilation point(with a other wavelength, feynman diagramm)... how can it be that there are "real-virtual" particle from inside deliver to outside the cavity. I think i've got read about the energy to create those particles is spent by the quantum vacuum energy for a short while to get real particles, real particles can interact with other real particles and the copper is a great barrier for the positrons and electrons. Don't know how this particle can escape. Please help me to understand. Got i am wrong or not? If i am wrong Hawking radiation is also.
Quote from: X_RaY on 07/14/2015 09:20 pmIs there someone who explain me the following?I don't understand in Dr White's theory of virtual electrons and positrons:This particles are real after creation (for a really short time, not an infinite) and are able to interact with the copper at the large diameter. If a created positron for example interacts with a electron inside the copper it'll annihilate and erased, at the same time a photon will radiate from the annihilation point(with a other wavelength, feynman diagramm)... how can it be that there are "real-virtual" particle from inside deliver to outside the cavity. I think i've got read about the energy to create those particles is spent by the quantum vacuum energy for a short while to get real particles, real particles can interact with other real particles and the copper is a great barrier for the positrons and electrons. Don't know how this particle can escape. Please help me to understand. Got i am wrong or not? If i am wrong Hawking radiation is also. My guess, and it's just a guess mind you, is that it is exactly the same phenomenon that results in tunnelling. That is, the annihilation results in the the creation, but not at exactly the same point but somewhere near-by in the QV. I don't know what "near-by" means in the QV world but I suspect that statistically, the outside of the copper is within reach. And I think this idea could extend to superluminal velocity of evanescent photons. They don't really go faster than speed of light, they tunnel, and tunnelling is near instantaneous. Again, just a guess, no math for it.
Quote from: rfcavity on 07/14/2015 07:48 pmQuote from: SeeShells on 07/14/2015 05:42 pmBusy morning and thought I'd give you all a update on the build. Thank goodness for gofundme I couldn't be doing this and I'd be hanging this baby off my bathroom shower curtain rod or throwing into my hot tub. http://www.gofundme.com/yy7yz3kI just ordered hollow carbon fiber rods 12.7 mm x 1.8 m, weight 354 grams or about 12 oz for the test Fulcrum to measure thrust.I've ordered a Raspberry Pi 2 Model B (1GB) Ultimate Starter Kit-- Includes over 40 components--Raspberry Pi 2 Model B--200 Page User Guide--Edimax EW-7811Un 150Mbps for data logging.Added a iPazzPort Raspberry Pi Mini Wireless Handheld Remote Control Keyboard with Multi Touch Touchpad Work for Android and Google Smart TV XBMC KP-810-21B for remote control and added a 32gb San disk for a great price.I've got 2 sheets of perforated copper on order 3x5 ft ~.020 thick for making the test dummy Plus a sheet of O2 free copper conductive .040 perforated copper for the real test.I've got price quotes coming from L3 for a complete power supply with a .01-50% duty cycle along with a 800w magnetron water cooled.If that doesn't work out and proves to much than I'll use for first test a standard 800 w OTS magnetron and power supply.What else? Oh ya, a http://www.ebay.com/itm/138M-4-4G-SMA-signal-source-generator-simple-spectrum-analyzer-Tracking-source-/111493176997?pt=LH_DefaultDomain_0&hash=item19f582dea5I've got wires and silver solder and cables on order Shielded where needed. Oh and a couple of inexpensive lasers and mirrors and graph paper, a tub and foam for the anti-vibration component of the test.I have a android pad w/wifi and blue tooth that I'll use as well.Now starts the process of putting it all together getHere we go!!! I'm so jazzed to see this project go ahead. Note to self, don't talk on the phone while typing.. sheesh.I don't understand why perforated copper sheets instead of solid. At that frequency it will decrease the effective conductivity and ruin the Q of any cavity. Additionally you lose structural rigidity and will be suspect to thermal effects changing the shape of the cavity (having a variable Q).Think the only reasons are one can look into the cavity(possible plasma strokes) and the thermal heated gas can evacuated it selves by convection... Q can only be less than in a solid case. But i also think these are interesting experiments, we will see whats happens and the "bandwidth" of experiments can't be high enough
Quote from: SeeShells on 07/14/2015 05:42 pmBusy morning and thought I'd give you all a update on the build. Thank goodness for gofundme I couldn't be doing this and I'd be hanging this baby off my bathroom shower curtain rod or throwing into my hot tub. http://www.gofundme.com/yy7yz3kI just ordered hollow carbon fiber rods 12.7 mm x 1.8 m, weight 354 grams or about 12 oz for the test Fulcrum to measure thrust.I've ordered a Raspberry Pi 2 Model B (1GB) Ultimate Starter Kit-- Includes over 40 components--Raspberry Pi 2 Model B--200 Page User Guide--Edimax EW-7811Un 150Mbps for data logging.Added a iPazzPort Raspberry Pi Mini Wireless Handheld Remote Control Keyboard with Multi Touch Touchpad Work for Android and Google Smart TV XBMC KP-810-21B for remote control and added a 32gb San disk for a great price.I've got 2 sheets of perforated copper on order 3x5 ft ~.020 thick for making the test dummy Plus a sheet of O2 free copper conductive .040 perforated copper for the real test.I've got price quotes coming from L3 for a complete power supply with a .01-50% duty cycle along with a 800w magnetron water cooled.If that doesn't work out and proves to much than I'll use for first test a standard 800 w OTS magnetron and power supply.What else? Oh ya, a http://www.ebay.com/itm/138M-4-4G-SMA-signal-source-generator-simple-spectrum-analyzer-Tracking-source-/111493176997?pt=LH_DefaultDomain_0&hash=item19f582dea5I've got wires and silver solder and cables on order Shielded where needed. Oh and a couple of inexpensive lasers and mirrors and graph paper, a tub and foam for the anti-vibration component of the test.I have a android pad w/wifi and blue tooth that I'll use as well.Now starts the process of putting it all together getHere we go!!! I'm so jazzed to see this project go ahead. Note to self, don't talk on the phone while typing.. sheesh.I don't understand why perforated copper sheets instead of solid. At that frequency it will decrease the effective conductivity and ruin the Q of any cavity. Additionally you lose structural rigidity and will be suspect to thermal effects changing the shape of the cavity (having a variable Q).
Busy morning and thought I'd give you all a update on the build. Thank goodness for gofundme I couldn't be doing this and I'd be hanging this baby off my bathroom shower curtain rod or throwing into my hot tub. http://www.gofundme.com/yy7yz3kI just ordered hollow carbon fiber rods 12.7 mm x 1.8 m, weight 354 grams or about 12 oz for the test Fulcrum to measure thrust.I've ordered a Raspberry Pi 2 Model B (1GB) Ultimate Starter Kit-- Includes over 40 components--Raspberry Pi 2 Model B--200 Page User Guide--Edimax EW-7811Un 150Mbps for data logging.Added a iPazzPort Raspberry Pi Mini Wireless Handheld Remote Control Keyboard with Multi Touch Touchpad Work for Android and Google Smart TV XBMC KP-810-21B for remote control and added a 32gb San disk for a great price.I've got 2 sheets of perforated copper on order 3x5 ft ~.020 thick for making the test dummy Plus a sheet of O2 free copper conductive .040 perforated copper for the real test.I've got price quotes coming from L3 for a complete power supply with a .01-50% duty cycle along with a 800w magnetron water cooled.If that doesn't work out and proves to much than I'll use for first test a standard 800 w OTS magnetron and power supply.What else? Oh ya, a http://www.ebay.com/itm/138M-4-4G-SMA-signal-source-generator-simple-spectrum-analyzer-Tracking-source-/111493176997?pt=LH_DefaultDomain_0&hash=item19f582dea5I've got wires and silver solder and cables on order Shielded where needed. Oh and a couple of inexpensive lasers and mirrors and graph paper, a tub and foam for the anti-vibration component of the test.I have a android pad w/wifi and blue tooth that I'll use as well.Now starts the process of putting it all together getHere we go!!! I'm so jazzed to see this project go ahead. Note to self, don't talk on the phone while typing.. sheesh.
I'll try to write a step-by-step guide soon so others can do what I am doing in order to provide more data to the scientists.
..You have confused me. Did you transpose the matrix? My csv files have 245 rows and JA columns = 261 columns.I will trust that you intended "rows" instead of "columns," because the x dimension corresponding to length is smaller than the y,z dimension corresponding to diameter of the cavity.