Apologies to all. I thought I had read all the older forum pages. Seems I missed quite a few. Just about finished.What I did find and confirmed via a search is that Shawyer's latest revelation, in an email to Mullerton, was that the Flight Thruster end plates WERE SHAPED seems to have missed making the headlines.I did read there was quite a bit of speculation during the time the Flight Thruster dimensions were being worked out as to whether the end plates were flat or shaped.So how we have it from Shawyer himself, the Flight Thruster was designed to have a high Q (narrow bandwidth), use a narrow band RF generator and have shaped end plates. Seems we finally know for sure why the end plates were so thick.
Quote from: TheTraveller on 05/05/2015 04:15 pmApologies to all. I thought I had read all the older forum pages. Seems I missed quite a few. Just about finished.What I did find and confirmed via a search is that Shawyer's latest revelation, in an email to Mullerton, was that the Flight Thruster end plates WERE SHAPED seems to have missed making the headlines.I did read there was quite a bit of speculation during the time the Flight Thruster dimensions were being worked out as to whether the end plates were flat or shaped.So how we have it from Shawyer himself, the Flight Thruster was designed to have a high Q (narrow bandwidth), use a narrow band RF generator and have shaped end plates. Seems we finally know for sure why the end plates were so thick.euhmm... came to the same conclusion...just didn't add the pretty pictures... http://forum.nasaspaceflight.com/index.php?topic=36313.msg1369324#msg1369324
Quote from: TheTraveller on 05/05/2015 01:11 pmHere is my KISS EMDrive test system rough draught.The EM Drive will sit on top of but not connected to one end of a balance beam. On the other will be an adjustable counter balance mass. Very low stiction bearings will be used.The EM Drive end of the balance beam will sit on top of but not connected to a digital load cell with a 0.01g resolution / 0.5kg max and be connected via USB to a laptop running data logger software. Would like more resolution, will see how the budget goes.The counter balance will be adjusted to produce a down force on the load cell of 0.25kg when the EM Drive is unpowered so to bias the load cell into the middle of it's range.The frequency and power adjustable RF source will be connected to the EM Drive by a free floating length of coax with SWR matching capability and to the laptop via USB connector. Control of frequency and power will be via software on the laptop.Fairly long power pulses of of upto 2 minutes will be applied to the EM Drive as per Shawyer's 1st test protocol. http://emdrive.com/feasibilitystudy.htmlThe idea is to keep this KISS and stay as close to the 1st Shawyer test setup that also used vertical orientation of the EM Drive.Based on achieving 10mN/kW (~1gf/kW) performance, the desired 0.1gf (10x load cell resolution) will need the application of 100W of RF power.Desire is to use common 2.4GHz narrow band WiFi based signal generators which can be smoothly varied in frequency and power output to find optimal cavity frequency and energy loading.As this is a narrow band RF signal, ideally the end caps should be spherical to eliminate end plate variable phase change and to get a much better cavity Q. But being a realist and KISS engineer, who hates to reinvent the wheel, will start with simpler flat plates and will follow the excellent work of Mullerton.Comments most welcomeOne possible problem I see with your proposed experiment is the coiled coax. There will always be a significant error force from that and there is no simple way of cancelling it out. Maybe a telescoping waveguide feed would solve that problem. The load cell will also be in jeopordy. Too much imbalance will crush it.
Here is my KISS EMDrive test system rough draught.The EM Drive will sit on top of but not connected to one end of a balance beam. On the other will be an adjustable counter balance mass. Very low stiction bearings will be used.The EM Drive end of the balance beam will sit on top of but not connected to a digital load cell with a 0.01g resolution / 0.5kg max and be connected via USB to a laptop running data logger software. Would like more resolution, will see how the budget goes.The counter balance will be adjusted to produce a down force on the load cell of 0.25kg when the EM Drive is unpowered so to bias the load cell into the middle of it's range.The frequency and power adjustable RF source will be connected to the EM Drive by a free floating length of coax with SWR matching capability and to the laptop via USB connector. Control of frequency and power will be via software on the laptop.Fairly long power pulses of of upto 2 minutes will be applied to the EM Drive as per Shawyer's 1st test protocol. http://emdrive.com/feasibilitystudy.htmlThe idea is to keep this KISS and stay as close to the 1st Shawyer test setup that also used vertical orientation of the EM Drive.Based on achieving 10mN/kW (~1gf/kW) performance, the desired 0.1gf (10x load cell resolution) will need the application of 100W of RF power.Desire is to use common 2.4GHz narrow band WiFi based signal generators which can be smoothly varied in frequency and power output to find optimal cavity frequency and energy loading.As this is a narrow band RF signal, ideally the end caps should be spherical to eliminate end plate variable phase change and to get a much better cavity Q. But being a realist and KISS engineer, who hates to reinvent the wheel, will start with simpler flat plates and will follow the excellent work of Mullerton.Comments most welcome
Quote from: Flyby on 05/05/2015 04:48 pmQuote from: TheTraveller on 05/05/2015 04:15 pmApologies to all. I thought I had read all the older forum pages. Seems I missed quite a few. Just about finished.What I did find and confirmed via a search is that Shawyer's latest revelation, in an email to Mullerton, was that the Flight Thruster end plates WERE SHAPED seems to have missed making the headlines.I did read there was quite a bit of speculation during the time the Flight Thruster dimensions were being worked out as to whether the end plates were flat or shaped.So how we have it from Shawyer himself, the Flight Thruster was designed to have a high Q (narrow bandwidth), use a narrow band RF generator and have shaped end plates. Seems we finally know for sure why the end plates were so thick.euhmm... came to the same conclusion...just didn't add the pretty pictures... http://forum.nasaspaceflight.com/index.php?topic=36313.msg1369324#msg1369324You certainly did! You also ended up with a bottom-of-the-page post, which are fairly easy to miss; that never helps.
Quote from: zellerium on 05/04/2015 07:41 pmQuote from: zen-in on 05/04/2015 07:21 pmQuote from: TheTraveller on 05/04/2015 04:51 pmChinese did report their cavity bandwidth data: http://www.emdrive.com/yang-juan-paper-2012.pdfInteresting. Earlier in the first thread the discussion centered around cavity Q and the need for a high Q. This cavity only has a Q = 1531.The 2013 paper from NWPU: "It was found that the thrustercavity made by copper and resonating on the equivalent TE011mode has a quality factor 320400 and generates total net EMthrust 411 mN for 1000 W 2.45 GHz incident microwave." http://iopscience.iop.org/1674-1056/22/5/050301The Q's reported in the tables 1 and 2 of http://www.emdrive.com/NWPU2010paper.pdf and in the above quote are much higher than the calculated Q based on the bandwidth. Zen-In's calculated Q from the bandwidth is correct: Q = f/bandwidthf (by definition)Can anybody make sense of the discrepancy?
Quote from: zen-in on 05/04/2015 07:21 pmQuote from: TheTraveller on 05/04/2015 04:51 pmChinese did report their cavity bandwidth data: http://www.emdrive.com/yang-juan-paper-2012.pdfInteresting. Earlier in the first thread the discussion centered around cavity Q and the need for a high Q. This cavity only has a Q = 1531.The 2013 paper from NWPU: "It was found that the thrustercavity made by copper and resonating on the equivalent TE011mode has a quality factor 320400 and generates total net EMthrust 411 mN for 1000 W 2.45 GHz incident microwave." http://iopscience.iop.org/1674-1056/22/5/050301
Quote from: TheTraveller on 05/04/2015 04:51 pmChinese did report their cavity bandwidth data: http://www.emdrive.com/yang-juan-paper-2012.pdfInteresting. Earlier in the first thread the discussion centered around cavity Q and the need for a high Q. This cavity only has a Q = 1531.
Chinese did report their cavity bandwidth data: http://www.emdrive.com/yang-juan-paper-2012.pdf
I am afraid that Star-Drive...aka Paul March isn't coming back. We had such a productive collaboration. That was open source science happening right before the World's eyes.We'll reach the stars someday, and you're getting us there...one data point at a time.
I am afraid that Star-Drive...aka Paul March may not come back. We had such a productive collaboration. That was open source science happening right before the World's eyes.We'll reach the stars someday, and you're getting us there...one data point at a time.
BTW, I think Mr. Shawyer claimed that there was no dielectric inserted into his cavity at all because it was not needed for its functioning. Technically though, that's not possible with materials like copper and aluminum. They instantly oxidize during manufacture of the cavity. So, the standing EM waves will encounter a dielectric on any metallic surface.
Quote from: Mulletron on 05/05/2015 05:21 pmI am afraid that Star-Drive...aka Paul March isn't coming back. We had such a productive collaboration. That was open source science happening right before the World's eyes.We'll reach the stars someday, and you're getting us there...one data point at a time.Have you heard something to that effect ? I have heard it said that NASA has asked them to not discuss NASA work in any public forum, because of what was written in the media (NASA warping space by accident, NASA working on a Star-Trek spaceship, etc.) .
Quote from: Flyby on 05/05/2015 03:05 pmwhile realizing my knowledge of electromagnetism falls short compared to level that is discussed here, i do have a question about that interesting idea on momentum transfer of the waves : -with the law on conservation of energy in the back of my head - How can the momentum transfer of a wave be bigger then the energy contained in a photon, as seen in a pure photon rocket ? I believe calculations showed the forces observed in the frustum are many times (100? 1000?) greater then what a photon rocket would be able to produce...Due to the duality of microwave being a photon particle and a wave at the same time, shouldn't the energy contained in a wave/particle be the same?Is it because for a photon rocket only a small portion of that energy is used for kinetic motion, while in the momentum transfer a greater part of the energy is transferred? Concerning Todd's formulation, I attach below his reply that was posted in another thread, that may also be of help concerning the above question:COM=conservation of momentumGR=General RelativityHis answer has to do with the "gravitational field" inside the cavity, which can have different levels of energy :(in one post he suggested that the experimenters should post a label on the frustum reading "Gravitational Field Inside")
while realizing my knowledge of electromagnetism falls short compared to level that is discussed here, i do have a question about that interesting idea on momentum transfer of the waves : -with the law on conservation of energy in the back of my head - How can the momentum transfer of a wave be bigger then the energy contained in a photon, as seen in a pure photon rocket ? I believe calculations showed the forces observed in the frustum are many times (100? 1000?) greater then what a photon rocket would be able to produce...Due to the duality of microwave being a photon particle and a wave at the same time, shouldn't the energy contained in a wave/particle be the same?Is it because for a photon rocket only a small portion of that energy is used for kinetic motion, while in the momentum transfer a greater part of the energy is transferred?
Quote from: CW on 05/05/2015 04:29 pmI was wondering about the following:The tapered frustum's sole purpose is to create a standing EM wave of specific frequency. As far as I remember, a standing wave could also be interpreted as a confined particle in quantum mechanics. Is there any possibilty that the standing waves within the cavity resemble dynamically created exotic matter that shows weird behavior when interacting with the 'normal' matter that the EM-drive is made of?This is at least similar to some claims made by Dr white. However I am not sure I have properly understood what he meant when he said these things are doing essentially the same thing the QVPT does and (I think?) maybe he said the QVPT and the Warp Interferometry test article got it's negative energy from the vacuum. Anyhow it may be that your supposition aligns with Dr White but i am not completely sure I understand it.
I was wondering about the following:The tapered frustum's sole purpose is to create a standing EM wave of specific frequency. As far as I remember, a standing wave could also be interpreted as a confined particle in quantum mechanics. Is there any possibilty that the standing waves within the cavity resemble dynamically created exotic matter that shows weird behavior when interacting with the 'normal' matter that the EM-drive is made of?