I have not seen anything in the Forbes article that refers to any new finding. In fact the article is even-handed and points out other peer reviewed papers that were later retracted after being proven false. I assume the following papers that are mentioned in the article were all retracted:quoted from recent Forbes article"Does it mean the science is correct, the effect is real and that physics is broken? Consider that peer-reviewed journals publish all sorts of results that later turn out to be spurious, including: the faster-than-light neutrinos that turned out to be a loose cable, the existence of the exoplanet Alpha Centauri Bb, which turned out to not exist, and the existence of a new LHC particle at 750 GeV, whose signal went away with more data."end of quote
Quote from: TheTraveller on 09/03/2016 05:47 pmIt would appear from the comments made here, the full EW paper has reached beyond EWs and AIAA. Seems Dr White sent it to Mark Rademaker, who modelled Dr White's IXS Enterprise warp ship. I predict it will see the light of day well before AIAA publishes it.http://www.forbes.com/sites/startswithabang/2016/09/02/nasas-impossible-space-engine-the-emdrive-passes-peer-review/#6ab6875a692cThe information below was not in that released by Dr. Rodal. It must be from the full paper:QuoteFor the EMdrive, the device that was tested here, thrust was consistently observed on the device to be between 30-and-50 microNewtons, giving us that 1.2 N/MW figure. But the limits of the measuring device’s threshold was just 10-to-15 microNewtons! In other words, these results may be consistent and interesting, but this isn’t as robust as anyone wants it to be.I am disappointed to see that "30-50 microNewtons" number. It is just in the range of Lorentz force you would see with a few amperes DC, several hundred cm^2 closed current loop, and the earth's magnet field. It looks like they did not avoid the same old flaw they made in their 2014 paper (see http://arxiv.org/pdf/1510.07752v1 for that flaw). After all, they got to know that flaw after their new test was done.
It would appear from the comments made here, the full EW paper has reached beyond EWs and AIAA. Seems Dr White sent it to Mark Rademaker, who modelled Dr White's IXS Enterprise warp ship. I predict it will see the light of day well before AIAA publishes it.http://www.forbes.com/sites/startswithabang/2016/09/02/nasas-impossible-space-engine-the-emdrive-passes-peer-review/#6ab6875a692cThe information below was not in that released by Dr. Rodal. It must be from the full paper:QuoteFor the EMdrive, the device that was tested here, thrust was consistently observed on the device to be between 30-and-50 microNewtons, giving us that 1.2 N/MW figure. But the limits of the measuring device’s threshold was just 10-to-15 microNewtons! In other words, these results may be consistent and interesting, but this isn’t as robust as anyone wants it to be.
For the EMdrive, the device that was tested here, thrust was consistently observed on the device to be between 30-and-50 microNewtons, giving us that 1.2 N/MW figure. But the limits of the measuring device’s threshold was just 10-to-15 microNewtons! In other words, these results may be consistent and interesting, but this isn’t as robust as anyone wants it to be.
The thruster was designed around a Siemens dielectric resonator type LN89/52B with a dielectric constant (er) of 38. An operating frequency of 2450 MHz was selected to allow a commercial 850 W magnetron to be used as a power source. A tapered circular waveguide was designed with TM01 as the dominant mode of propagation.
Finally the overall electrical length of the thruster must be a multiple of e/2 wheree is the effective wavelength of the thruster. This effective wavelength will equateto different values of physical length throughout the waveguide assembly.The overall geometry was defined by building a mathematical model of the thrusterbased on an Excel spreadsheet. The physical length was divided into 0.5mm sectionsand the guide wavelength calculated for each section. The electrical length for thatsection was calculated and the summation of the section electrical lengths calculated.Thus variations of diameters, lengths and er could be modelled, with the target ofachieving an overall electrical length equal to ne/2.The model also allowed the operation to be modelled in TE11 and TE12 modes, thenearest unwanted modes. The design was optimised to avoid the possibility of anyunwanted mode operation.
Jeez, I go on vacation for three days, and the global press goes wild over a single post on this subthread while Im gone. Again!It's a helluva important topic being silently followed all the time by people who don't post, but who are press members (and bots). Please use solid judgement on this thread friends....and I'm thrilled to be a part of it.
Quick question wouldn't a super conducting drive be of very little use at this time as we don't have practical room temperature super conducting materials so such a device would constantly have to be cooled down?
COOLINGThe 5 thrusting cavities are cooled by radiative cooling to deep space. The maximum design temperature of cavity operation is 75 K. The cavities and structural elements around the cavities are coated with a high emissivity black finish. At design power, the thruster cavities receive a combined 73 watts of phase-locked RF power. This power is almost entirely consumed as ohmic heating in the walls of the cavities. The cavities continually radiate this heat to deep space.The radiating surface area of the thruster section of the probe is approximately 90 square meters. The radiative surface area needed to radiate 73 watts from a temperature of 75 K to 3 K (the effective temperature of deep space) is 40 square meters. When the cavities radiate more than 73 watts of thermal energy, the operating temperature of the cavities drops below 75 K, reducing the radiative power of the cooling mechanism. The system will reach a natural equilibrium temperature that radiates all ohmic heating from the cavity walls. This equilibrium temperature will be below the 75 K maximum design temperature. Operating temperatures below 75 K will improve the surface resistance characteristics of the YBCO and improve the power-to-thrust performance of the propulsion system.This radiative cooling system is passive. There are no moving parts to wear out or malfunction. This ensures that the cooling system operational life is sufficient to meet the design lifetime of the probe.The smaller Cannae Drive cavities are operated intermittently to control the yaw, pitch, and roll of the probe. Cooling requirements on these cavities is minimal compared to the cooling load on the thrusting cavities. The small cavities in the probe also use passive radiative cooling (to deep space) to maintain operating temperature at or below 75 K.
Quote from: Star One on 09/05/2016 10:38 amQuick question wouldn't a super conducting drive be of very little use at this time as we don't have practical room temperature super conducting materials so such a device would constantly have to be cooled down?In space all that is needed is to shield the EmDrive from the sun and it will cool to a very low temperature with no auxiliary cooling needed. Cannae plan to use this form of cooling on their thrusters.http://cannae.com/deep-space-probesQuoteCOOLINGThe 5 thrusting cavities are cooled by radiative cooling to deep space. The maximum design temperature of cavity operation is 75 K. The cavities and structural elements around the cavities are coated with a high emissivity black finish. At design power, the thruster cavities receive a combined 73 watts of phase-locked RF power. This power is almost entirely consumed as ohmic heating in the walls of the cavities. The cavities continually radiate this heat to deep space.The radiating surface area of the thruster section of the probe is approximately 90 square meters. The radiative surface area needed to radiate 73 watts from a temperature of 75 K to 3 K (the effective temperature of deep space) is 40 square meters. When the cavities radiate more than 73 watts of thermal energy, the operating temperature of the cavities drops below 75 K, reducing the radiative power of the cooling mechanism. The system will reach a natural equilibrium temperature that radiates all ohmic heating from the cavity walls. This equilibrium temperature will be below the 75 K maximum design temperature. Operating temperatures below 75 K will improve the surface resistance characteristics of the YBCO and improve the power-to-thrust performance of the propulsion system.This radiative cooling system is passive. There are no moving parts to wear out or malfunction. This ensures that the cooling system operational life is sufficient to meet the design lifetime of the probe.The smaller Cannae Drive cavities are operated intermittently to control the yaw, pitch, and roll of the probe. Cooling requirements on these cavities is minimal compared to the cooling load on the thrusting cavities. The small cavities in the probe also use passive radiative cooling (to deep space) to maintain operating temperature at or below 75 K.EmDrive Engineering 101.
On most spacecraft, one would use helium as a liquid cryogen of choice (regardless of the deviceoperating temperature) because the total enthalpy per unit cryogen mass available from the boilingtemperature to 300 K is highest for any fluid (except for hydrogen). Hydrogen is a special case. It hasgood heat transfer properties and the largest total enthalpy of any fluid. The problem is its flammability.Solid hydrogen can be used for space cryogenic cooling of devices (above 13 K) on satellites launchedusing non-manned expendable rockets.
Cryogenic Engineering 100...
Quote from: Rodal on 09/05/2016 02:30 pmCryogenic Engineering 100...All very interesting. But at that point it's just a complex engineering problem, no? If the concept itself is actually valid, the rest is just many hours of work and creative solutions. That's a huge leap forward considering the entire idea has largely been characterized as a little-understood long-shot that is probably experimental error at best, and fraudulent quackery at worst.
I find it hard to connect the quote from Cannae with the comments on cryo-coolers.The Cannae quote speaks of passive cooling, which sounds like it needs no cryo-cooler, no?Assuming they know what the advantage of propellant-less propulsion is, it's possible they may have twigged that needing a supply of coolant is a bad thing.But: there are Ne tanks in the drawing, don't know what for. Maybe they need something which is still gaseous when passively cooled.I agree this is better in space than in your regular flying car.....
Quote from: RERT on 09/05/2016 05:00 pmI find it hard to connect the quote from Cannae with the comments on cryo-coolers.The Cannae quote speaks of passive cooling, which sounds like it needs no cryo-cooler, no?Assuming they know what the advantage of propellant-less propulsion is, it's possible they may have twigged that needing a supply of coolant is a bad thing.But: there are Ne tanks in the drawing, don't know what for. Maybe they need something which is still gaseous when passively cooled.I agree this is better in space than in your regular flying car.....I imagine any terrestrial flying vehicles using EM drives are going to be nothing like we know now. Weirdly this is the area something like this would be most useful outside of space as we already have electric cars but we do not have large electric planes for when jets must go.
Quote from: Star One on 09/05/2016 05:48 pmQuote from: RERT on 09/05/2016 05:00 pmI find it hard to connect the quote from Cannae with the comments on cryo-coolers.The Cannae quote speaks of passive cooling, which sounds like it needs no cryo-cooler, no?Assuming they know what the advantage of propellant-less propulsion is, it's possible they may have twigged that needing a supply of coolant is a bad thing.But: there are Ne tanks in the drawing, don't know what for. Maybe they need something which is still gaseous when passively cooled.I agree this is better in space than in your regular flying car.....I imagine any terrestrial flying vehicles using EM drives are going to be nothing like we know now. Weirdly this is the area something like this would be most useful outside of space as we already have electric cars but we do not have large electric planes for when jets must go.One can guess they might look more like Shuttlecraft. They would gently lift up with no need of runways or airports, climb to where the atmosphere is thin or basically none, no need to go more than a few Mach since no point on Earth is more than 12,000 miles away, then slow and gently land. I limit the speed so a failure of the lift engines would not force anything like a full orbital re-entry with all that heat. I would also add backup parachutes in my design so it could float back if necessary.