July 25, 2015
http://nextbigfuture.com/
The Emdrive has been proposed as a propellantless space propulsion.
NASA had investigated and found measurable propulsion.
Now German researchers Emdrive experiments have eliminated other possible sources of error and still measure a small (20 micronewtons) of propulsive force.
There is a lot of discussion of the Emdrive experiment on the NASA space flight forum.
Cavity Length(m) = 0.0686
Big Diameter(m) = 0.0541
Small Diameter(m) = 0.0385
Dielectric = None
Frequency = 2.44Ghz
Input Power = 700w (output of magnetron)
Pressure = 4×10^-6
Q = 20.3 (seems like this was measured and calculated after they finished all reported testing)
Force (milliNewtons) = 0.02 (20 micronewtons)
Martin Tajmar has looked at other possibile alternative space propulsion approaches.
* He looked at using "negative matter" from a theoretical perspective -- theoretical because of the difficulty of producing such a substance, which is not as easy as simple antimatter.
* He has investigated claims of "electrostatic torque," a twisting force meant to occur between charged spheres, and found the supposed anomaly was due to a slight asymmetry in the experimental setup.
* He experimented to look into claims of gravitational shielding with spinning superconductors. This led to a better understanding of sources of error in high-precision gyroscope measurements. These are cases where an apparatus apparently producing small anomalous forces needed to be examined closely.
Paul March had provided updates on the EMdrive and Cannae drive experiments at Eagleworks NASA in April.
If one envisions the quantum vacuum (Q-V) as a semi-virtual electrical plasma as Dr. White does, that would imply that the Poynting power flow vector would entrain the Q-V plasma and send it on its way toward the pillbox end of the cavity and then out of the cavity, the back-reaction on the cavity should be in the opposite direction towards the RF feed end of the Cannae test article, but the observed thrust vector is opposite to that surmise, i.e. toward the shorter RF sense antenna end of the cavity per the attached slide.
Now Per the newly authored Q-V plasma simulation code that Dr. White just finished, the equal bidirectional Q-V plasma flow for the Cannae cavity comes from the high-Q pancake section with a Q of ~9,000 for the un-slotted version of the cavity. However due to the high E-field region created n the throat of the RF feed, this cylindrically shaped high E-field volume acts as an obstruction to the Q-V plasma flow. This E-field obstruction created in the PTFE cylinder then accelerates the Q-V plasma around it in a Bernoulli like effect that accelerates the Q-V plasma flow coming from the main pillbox cavity. This unbalanced and accelerated Q-V plasma flow that goes away from the large pill box cavity in the direction of the RF input section is what generates the NET thrust in our model.
Next, using this new Q-V plasma simulation tool that utilizes the instantaneous E&M fields from COMSOL for one complete RF cycle in 5 degree increments as its input file, we are now seeing why we need the PTFE or HDPE dielectrics in the frustum while using near pure sine wave power levels below ~100W in the ~2.0 GHz frequency range to generate detectable thrust, and why Shawyer and the Chinese didn't while pumping 80W to 2,500W using magnetron RF sources. We think the reasons are two fold.
The first is that Shawyer and the Chinese both used magnetron RF sources for their experiments. An RF source that generates large AM, FM and PM modulation of the carrier wave with typical FM modulation bandwidth on the order of at least +/-20 MHz. (These time rate to change of energy modulations increase the Q-V density in our model.)
The second reason we found running these 3D Q-V plasma simulations for the EMPTY copper frustum, was that increasing the input power tends to focus the Q-V plasma flow from near omnidirectional from the frustum at low powers, to a much more jet like beam at higher powers measured in kW to tens of kW-rf. In fact the simulation for the 100W run predicted only ~50uN for our pure RF system with dielectric, while the 10kW run predicted a thrust level of ~6.0 Newton without a dielectric in the cavity. And at 100kW-rf it was now up to ~1300 Newton, but the input power to thrust production nonlinearity was starting to taper off around 50kW. Of course these Q-V plasma thrust predictions are based on the Q-V not being immutable and non-degradable, a feature we admit is not widely accepted by the mainstream physics community, at least at the moment.
Due to the above non-linear thrust scaling with input power predictions, we have started the build up of a 100W-to-1,200W waveguide magnetron RF power system that will drive one of our aluminum RF frustum cavities. Initially the test rig will follow Shawyer's first generation test rig that used a tetter-totter balance system in air only to see if we can generate similar thrust levels that Shawyer reported using a hermetic sealed box, which were in the ~16 to 300 milli-Newton range dependent on the Q-Factor of the frustum.
The other EMdrive experiment status
- Shawyer experiments in ambient air (as well as newer superconducting designs) are now kept under a shroud of secrecy.
- Chinese mid-to-high power experimental results (~ 2000 W) in ambient air are on the contrary regularly published in academic journals, but are still uncertain because Pr. Juan Yang is not able to share additional data, and spurious causes like air currents are not ruled-out.
There is information from Paul March on the testing of the controversial EMDrive at NASA Eagleworks. Paul commented on the NASA spaceflight forum.
Summary of EMdrive Past work
Experimental Thrust is at 50 micronewtons but need at least 100 micronewtons to go to Glenn Research Center (GRC) for a replication effort in the next few months
The NASA Eagleworks Lab is still working on the copper frustum thruster that was reported on last summer at the AIAA/JPC. They have now confirmed that there is a thrust signature in a hard vacuum (~5.0x10^-6 Torr) in both the forward direction, (approx. +50 micro-Newton (uN) with 50W at 1,937.115 MHz), and the reversed direction, (up to -16uN with a failing RF amp), when the thruster is rotated 180 degrees on the torque pendulum. However they continue to fight through RF amplifier failures brought on by having to operate them in a hard vacuum with few $$$ resources to fix them when they break, so the desired data is coming along very slowly. They are still working on obtaining enough data though that will allow us to go to Glenn Research Center (GRC) for a replication effort in the next few months. However that will only happen if they can make the thrust signature large enough since the GRC thrust stand can only measure down to ~50uN, so we have to get the thrust signature up to at least 100uN before they can go to GRC.
As to the theoretical side of Q-Thrusters, Dr. White has just developed the first cut at a quantum vacuum (QV) based plasma code written in C+ under Windows/Unix and VMD visualization software that utilizes the COMSOL E&M derived field data for a given thruster geometry that allows one to track the movement and velocity of a subset of the QV's electron/positron neutral plasma pairs in the thruster over time as they respond to the applied time varying RF E&M fields in the copper frustum resonant cavity and to each other. This package also allows one to calculate the expected thrust for a given input power and quality factor of the frustum resonant cavity based of standard plasma rocket physics. So far the estimated thrust verses experimental observations are within 2% for the first experimental data run I compared it to, but we still have a long, long road ahead of us of experimental validation before we have any real confidence in this very new Q-Thruster design tool.
Six months ago there was the big splash from the EMdrive and Cannae drive results.
The 21 page Anomalous Thrust Production from an RF Test Device Measured on a Low-Thrust Torsion Pendulum paper is online at Libertarian News.
Abstract - Anomalous Thrust Production from an RF Test Device Measured on a Low-Thrust Torsion Pendulum
This paper describes the test campaigns designed to investigate and demonstrate viability of using classical magnetoplasmadynamics to obtain a propulsive momentum transfer via the quantum vacuum virtual plasma. This paper will not address the physics of the quantum vacuum plasma thruster (QVPT), but instead will describe the recent test campaign. In addition, it contains a brief description of the supporting radio frequency (RF) field analysis, ssons learned, and potential applications of the technology to space exploration missions. During the first (Cannae) portion of the campaign, approximately 40 micronewtons of thrust were observed in an RF resonant cavity test article excited at approximately 935 megahertz and 28 watts. During the subsequent (tapered cavity) portion of the campaign, approximately 91 micronewtons of thrust were observed in an RF resonant cavity test article excited at approximately 1933 megahertz and 17 watts. Testing was performed on a low-thrust torsion pendulum that is capable of detecting force at a single-digit micronewton level. Test campaign results indicate that the RF resonant cavity thruster design, which is unique as an electric propulsion device, is producing a force that is not attributable to any classical electromagnetic phenomenon and therefore is potentially demonstrating an interaction with the quantum vacuum virtual plasma.
From the Full paper
Talk Polywell had an interesting comment on the full paper
Eagleworks tested one tapered (frustum) cavity, aka Shawyer's EmDrive; and two Cannae drives which are also asymmetric but different resonant cavities. The Cannae drive is said to work on a purported different principle than the EmDrive, according to its inventor Guido Fetta (a net Lorentz force imbalance of electrons upon top vs bottom wall of the cavity). According to this purported working principle, one Cannae drive had radial slots on its rim as required by Fetta in order to produce net thrust, and the second Cannae drive didn't have those slits and was intended to be a "null test device". But the Cannae null test article… also produced net thrust (20 to 40 µN of net thrust depending of the forward or backward direction).
The null device having thrust means that the Cannae drive theory that the slits mattered was not true. However, this is irrelevant as to whether the Cannae drive produces thrust. Another theoretical explanation is needed but the anomalous thrust remains
We're talking of net thrust because of course the setup was also tested with a null 50 ohm load connected, in order to cancel the effect from the drives and detect any detect any spurious force due to EM coupling with the whole apparatus (which exists, at 9.6 µN) and this "null" spurious force was evidently subtracted from any thrust signal due to the drives then tested on the pendulum.
All tests articles (the EmDrive version, the Cannae drive version, and even the Cannae "null test" version) had a dielectric embedded within. This is a hint for a different theoretical explanation involving EM fields, proper acceleration, mass fluctuation and dielectrics. Maybe Mach effects (due to Mach's principle), as supposed by Woodward and Fearn within the GR theory, or within a scalar-tensor theory of gravity according to Minotti.
The Cannae drive website from 2011 is still available on the web archive. Guido Fetta's Q drive work and his expectation to revolutionize space travel are on the site.
Fetta's experimental results are detailed. Also, numerical work and what he believes are the Principles.
EMDrive thrust does not seem to scale with higher Q with these tests
What space missions are possible with early versions if this is true?
Based on test data and theoretical model development, the expected thrust to power for initial flight applications is expected to be in the 0.4 newton per kilowatt electric (N/kWe) range, which is about seven times higher than the current state of the art Hall thruster in use on orbit today. The following figures show the value proposition for this class of electric propulsion. A conservative 300 kilowatt solar electric propulsion roundtrip human exploration class mission to Mars/Deimos. A 90 metric ton 2 megawatt (MW) nuclear electric propulsion mission to Mars that has considerable reduction in transit times due to having a thrust to mass ratio greater than the gravitational acceleration of the Sun (0.6 milli-g’s at 1 AU). The same spacecraft mass performing a roundtrip mission to the Saturn system spending over a year around two moons of interest, Titan and Enceladus. Even in this last class of mission which requires only a single heavy lift launch vehicle, the mission has less mission duration than is common with a current conjunction-class Mars mission using chemical propulsion systems and which would require multiple heavy lift launch vehicles. 300 kW SEP Roundtrip Mission to Mars Deimos (50 day stay) departing from DRO 300 kW SEP
What are the next research steps ?
The lessons learned with antenna design and location have been factored in and the design of both the drive and sense antenna s have been explicitly optimized to excite the RF thruster at the target frequency and mode (e.g.,the optimal location has been analytically determined). The thrust performance of this next generation tapered test article has been analytically determined to be in the 0.1 newton per kilowatt regime. Vacuum compatible RF amplifiers with power ranges of up to 125 watts will allow testing at vacuum conditions which was not possible using our current RF amplifiers due to the presence of electrolytic capacitors. The tapered thruster has a mechanical design such that it will be able to hold pressure at 14.7 pounds per square inch (psi) inside of the thruster body while the thruster is tested at vacuum to preclude glow discharge within the thruster body while it is being operated at high power. A phase lock loop (PLL) solution has already been implemented and evaluated at the 1 GHz frequency range, and is being tailored to be able to support testing at multiple set points all the way up to 2.5 GHz. The near term objective is to complete a Q -thruster breadboard test article that is capable of being shipped to other locations which possess the ability to measure low thrust for independent verification and validation (IV&V) of the technology. The current plan is to support an IV&V test campaign at the Glenn Research Center (GRC) using their low thrust torsion pendulum followed by a repeat campaign at the Jet Propulsion Laboratory (JPL) using their low thrust torsion pendulum. The Johns Hopkins University Applied Physics Laboratory has also expressed an interest in performing a Cavendish Balance style test with the IV and V shipset
SOURCES - AIAA, Nasa space flight forum, Wired UK
August 02, 2015
EMdrive paper and what original inventor Roger Shawyer believes is happening
The keys to EMDrive experiments are prove the propulsion is real and
will work in space. Find a way with theory or experiment to scale up the
effect.
If it is real and the effect can be scaled up then at the very least space travel is transformed.
Here is information from a Shawyer paper, his website FAQ and his videos. Roger Shawyer is the original inventor of the EMdrive.
* Not Reactionless, but propellentless
* Shawyer background was with UK Army research and then in the space industry
* Main players in UK, China and the USA are pursuing EMDrive research
* At least three other countries (that Shawyer knows about) have serious programs running and university departments and private individuals
Chinese Northwestern Polytechnical University
In 2008 a team of Chinese researchers led by Juan Yang, professor of propulsion theory and engineering of aeronautics and astronautics at NWPU, claimed to have developed a valid electro-magnetic theory behind a microwave resonant cavity thruster. A demonstration version of the drive was built and tested under different cavity shapes and at higher power levels in 2010. A maximum thrust of 720 mN was reported at 2,500 W of input power on an aerospace engine test stand usually used to precisely test spacecraft engines like ion drives. As of 2015, this is by far the most significant test of such a device to date - no other group has even announced plans to run tests at similar power levels.
Propulsion forces from NASA Eagleworks and the the German researchers are in the tens of micronewton range.
Shawyer has notes from his dynamic tests He claims to have achieved a thrust of 96 milli Newtons was produced for an input microwave power of 334 Watts.
Q. Is the thrust produced by the EmDrive a reactionless force?
A. No, the thrust is the result of the reaction between the end plates of the waveguide and the Electromagnetic wave propagated within it.
Q. How can a net force be produced by a closed waveguide?
A. At the propagation velocities (greater than one tenth the speed of light) the effects of special relativity must be considered. Different reference planes have to be used for the EM wave and the waveguide itself. The thruster is therefore an open system and a net force can be produced.
Q. Why does the net force not get balanced out by the axial component of the sidewall force?
A. The net force is not balanced out by the axial component of the sidewall force because there is a highly non linear relationship between waveguide diameter and group velocity. (e.g. at cut off diameter, the group velocity is zero, the guide wavelength is infinity, but the diameter is clearly not zero.) The design of the cavity is such that the ratio of end wall forces is maximised, whilst the axial component of the sidewall force is reduced to a negligible value.
Q. Does the theory of the EmDrive contravene the accepted laws of physics or electromagnetic theory?
A. The EmDrive does not violate any known law of physics. The basic laws that are applied in the theory of the EmDrive operation are as follows:
Newton’s laws are applied in the derivation of the basic static thrust equation (Equation 11 in the theory paper) and have also been demonstrated to apply to the EmDrive experimentally.
The law of conservation of momentum is the basis of Newtons laws and therefore applies to the EmDrive. It is satisfied both theoretically and experimentally.
The law of conservation of energy is the basis of the dynamic thrust equation which applies to the EmDrive under acceleration,(see Equation 16 in the theory paper).
The principles of electromagnetic theory are used to derive the basic design equations.
Q. Why does the EmDrive not contravene the conservation of momentum when it operates in free space?
A. The EmDrive cannot violate the conservation of momentum. The electromagnetic wave momentum is built up in the resonating cavity, and is transferred to the end walls upon reflection. The momentum gained by the EmDrive plus the momentum lost by the electromagnetic wave equals zero. The direction and acceleration that is measured, when the EmDrive is tested on a dynamic test rig, comply with Newtons laws and confirm that the law of conservation of momentum is satisfied.
Q. Is the EmDrive a form of perpetual motion machine?
A. The EmDrive obeys the law of conservation of energy and is therefore not a perpetual motion machine. Energy must be expended to accelerate the EmDrive (see Equation 16 of the theory paper). Once the EmDrive is switched off, Newton’s laws ensure that motion is constant unless it is acted upon by another force.
Q. Why does the thrust decrease as the spacecraft velocity along the thrust vector increases?
A. As the spacecraft accelerates along the thrust vector, energy is lost by the engine and gained as additional kinetic energy by the spacecraft. This energy can be defined as the thrust multiplied by the distance through which the thrust acts. For a given acceleration period, the higher the mean velocity, the longer the distance travelled, hence the higher the energy lost by the engine.
This loss of stored energy from the resonant cavity leads to a reduction in Q and hence a reduction of thrust.
EmDrive Interview with Roger Shawyer from Nick Breeze on Vimeo.
Roger Shawyer is the creator of EmDrive (Electromagnetic Thrust) technology. This interview was conducted in May 2015 by Nick Breeze.
Roger Shawyer invented the Emdrive. NASA is testing the EMdrive and the Cannae drive and getting interesting results Shawyer presented in October, 2014.
EMDrive results have not been conclusively proven yet and there is no proven underlying theory and any scaling has not been determined.
There are interesting results in the 50-900 micronewton ranges. There does seem to be scaling with increased power levels.
Shawyer sees scaling up the superconducting version of EMdrive to 300 Newtons per kilowatt combined with radioisotope thermoelectric generators or small scale nuclear fission systems to achieve 200 kilowatts for a Alpha Centauri ten year flyby probe. A probe that reaches about 60% of lightspeed and covers 4 light years in ten years.
300 newtons per kilowatt would be scaling up the energy to thrust efficiency by 300 times.
NASA Eagleworks now calculate scaling to many Newtons if EMdrive matches Sonny Whites quantum vacuum theories
NASA eagleworks calculate that if high power Magnetron enhancement works they could achieve 2000 newtons of thrust and high levels of newtons per kilowatt.
Sawyer projected interstellar probe
Shawyers's Development of a Demonstrator Engine
Although the experimental thruster had verified the static thrust equation, it became apparent that the concept would not become generally accepted until a viable engine could be demonstrated. Accordingly, a proposal for the design, manufacture and test of a complete demonstrator engine was submitted to DTI. A Research and Development grant was awarded in September 2003 and the work started with a mission analysis phase.
This work enabled the specification of the demonstrator engine to be optimised against the requirements of a typical commsat mission. Unlike the experimental thruster, the engine would be rated for continuous operation and extensive design work was required to increase the specific thrust by raising the design factor and unloaded Q.
The engine was built with a design factor of 0.844 and has a measured Q of 45,000 for an overall diameter of 280 mm. The microwave source is a water cooled magnetron with a variable output power up to a maximum of 1.2 kW.
To obtain the predicted thrust the engine must maintain stable resonance at this high Q value. Major design challenges have included thermal compensation, tuning control and source matching.
The engine was tested in a large static test rig employing a calibrated composite balance to measure thrust in 3 directions, up, down and horizontal. A total of 134 test runs were carried out over the full performance envelope, with a maximum specific thrust of 214mN/kW being measured.
If it is real and the effect can be scaled up then at the very least space travel is transformed.
Here is information from a Shawyer paper, his website FAQ and his videos. Roger Shawyer is the original inventor of the EMdrive.
* Not Reactionless, but propellentless
* Shawyer background was with UK Army research and then in the space industry
* Main players in UK, China and the USA are pursuing EMDrive research
* At least three other countries (that Shawyer knows about) have serious programs running and university departments and private individuals
Chinese Northwestern Polytechnical University
In 2008 a team of Chinese researchers led by Juan Yang, professor of propulsion theory and engineering of aeronautics and astronautics at NWPU, claimed to have developed a valid electro-magnetic theory behind a microwave resonant cavity thruster. A demonstration version of the drive was built and tested under different cavity shapes and at higher power levels in 2010. A maximum thrust of 720 mN was reported at 2,500 W of input power on an aerospace engine test stand usually used to precisely test spacecraft engines like ion drives. As of 2015, this is by far the most significant test of such a device to date - no other group has even announced plans to run tests at similar power levels.
Propulsion forces from NASA Eagleworks and the the German researchers are in the tens of micronewton range.
In an IAC13 paper the dynamic operation of a second generation superconducting EmDrive thruster was described. A mathematical model was developed and, in this paper, that model is used to extend the performance envelope of the technology. Three engine designs are evaluated. One is used as a lift engine for a launch vehicle, another as an orbital engine for the launcher and a third as the main engine for an interstellar probe.
The engines are based on YBCO superconducting cavities, and performance is predicted on the basis of the test data obtained in earlier experimental programmes. The Q values range from 80 million to 200 million and provide high values of specific force over a range of accelerations from 0.4 m/s/s to 6 m/s/s.
The launch vehicle is an “all-electric” single stage to orbit (SSTO) spaceplane, using a 900 MHz, eight cavities, fully gimballed lift engine. A 1.5 GHz fixed orbital engine provides the horizontal velocity component. Both engines use total loss liquid hydrogen cooling. Electrical power is provided by fuel cells, fed with gaseous hydrogen from the cooling system and liquid oxygen. A 2 ton payload, externally mounted, can be flown to Low Earth Orbit in a time of 27 min. The total launch mass is 10 ton, with an airframe styled on the X37B, which allows aerobraking and a glide approach and landing.
The full potential of EmDrive propulsion for deep space missions is illustrated by the performance of the interstellar probe. A multi-cavity, fixed 500 MHz engine is cooled by a closed cycle liquid nitrogen system. The refrigeration is carried out in a two stage reverse Brayton Cycle. Electrical power is provided by a 200 kWe nuclear generator. The 9 ton spacecraft, which includes a 1 ton science payload, will achieve a terminal velocity of 0.67c, (where c is the speed of light), and cover a distance of 4 light years, over the 10 year propulsion period.
The work reported in this paper has resulted in design studies for two Demonstrator spacecrafts. The launcher will demonstrate the long-sought-for, low cost access to space, and also meet the mission requirements of the proposed DARPA XS-1 Spaceplane. The probe will enable the dream of an interstellar mission to be achieved within the next 20 years.
Shawyer has notes from his dynamic tests He claims to have achieved a thrust of 96 milli Newtons was produced for an input microwave power of 334 Watts.
Q. Is the thrust produced by the EmDrive a reactionless force?
A. No, the thrust is the result of the reaction between the end plates of the waveguide and the Electromagnetic wave propagated within it.
Q. How can a net force be produced by a closed waveguide?
A. At the propagation velocities (greater than one tenth the speed of light) the effects of special relativity must be considered. Different reference planes have to be used for the EM wave and the waveguide itself. The thruster is therefore an open system and a net force can be produced.
Q. Why does the net force not get balanced out by the axial component of the sidewall force?
A. The net force is not balanced out by the axial component of the sidewall force because there is a highly non linear relationship between waveguide diameter and group velocity. (e.g. at cut off diameter, the group velocity is zero, the guide wavelength is infinity, but the diameter is clearly not zero.) The design of the cavity is such that the ratio of end wall forces is maximised, whilst the axial component of the sidewall force is reduced to a negligible value.
Q. Does the theory of the EmDrive contravene the accepted laws of physics or electromagnetic theory?
A. The EmDrive does not violate any known law of physics. The basic laws that are applied in the theory of the EmDrive operation are as follows:
Newton’s laws are applied in the derivation of the basic static thrust equation (Equation 11 in the theory paper) and have also been demonstrated to apply to the EmDrive experimentally.
The law of conservation of momentum is the basis of Newtons laws and therefore applies to the EmDrive. It is satisfied both theoretically and experimentally.
The law of conservation of energy is the basis of the dynamic thrust equation which applies to the EmDrive under acceleration,(see Equation 16 in the theory paper).
The principles of electromagnetic theory are used to derive the basic design equations.
Q. Why does the EmDrive not contravene the conservation of momentum when it operates in free space?
A. The EmDrive cannot violate the conservation of momentum. The electromagnetic wave momentum is built up in the resonating cavity, and is transferred to the end walls upon reflection. The momentum gained by the EmDrive plus the momentum lost by the electromagnetic wave equals zero. The direction and acceleration that is measured, when the EmDrive is tested on a dynamic test rig, comply with Newtons laws and confirm that the law of conservation of momentum is satisfied.
Q. Is the EmDrive a form of perpetual motion machine?
A. The EmDrive obeys the law of conservation of energy and is therefore not a perpetual motion machine. Energy must be expended to accelerate the EmDrive (see Equation 16 of the theory paper). Once the EmDrive is switched off, Newton’s laws ensure that motion is constant unless it is acted upon by another force.
Q. Why does the thrust decrease as the spacecraft velocity along the thrust vector increases?
A. As the spacecraft accelerates along the thrust vector, energy is lost by the engine and gained as additional kinetic energy by the spacecraft. This energy can be defined as the thrust multiplied by the distance through which the thrust acts. For a given acceleration period, the higher the mean velocity, the longer the distance travelled, hence the higher the energy lost by the engine.
This loss of stored energy from the resonant cavity leads to a reduction in Q and hence a reduction of thrust.
EmDrive Interview with Roger Shawyer from Nick Breeze on Vimeo.
Roger Shawyer is the creator of EmDrive (Electromagnetic Thrust) technology. This interview was conducted in May 2015 by Nick Breeze.
Roger Shawyer invented the Emdrive. NASA is testing the EMdrive and the Cannae drive and getting interesting results Shawyer presented in October, 2014.
EMDrive results have not been conclusively proven yet and there is no proven underlying theory and any scaling has not been determined.
There are interesting results in the 50-900 micronewton ranges. There does seem to be scaling with increased power levels.
Shawyer sees scaling up the superconducting version of EMdrive to 300 Newtons per kilowatt combined with radioisotope thermoelectric generators or small scale nuclear fission systems to achieve 200 kilowatts for a Alpha Centauri ten year flyby probe. A probe that reaches about 60% of lightspeed and covers 4 light years in ten years.
300 newtons per kilowatt would be scaling up the energy to thrust efficiency by 300 times.
NASA Eagleworks now calculate scaling to many Newtons if EMdrive matches Sonny Whites quantum vacuum theories
NASA eagleworks calculate that if high power Magnetron enhancement works they could achieve 2000 newtons of thrust and high levels of newtons per kilowatt.
Sawyer projected interstellar probe
Shawyers's Development of a Demonstrator Engine
Although the experimental thruster had verified the static thrust equation, it became apparent that the concept would not become generally accepted until a viable engine could be demonstrated. Accordingly, a proposal for the design, manufacture and test of a complete demonstrator engine was submitted to DTI. A Research and Development grant was awarded in September 2003 and the work started with a mission analysis phase.
This work enabled the specification of the demonstrator engine to be optimised against the requirements of a typical commsat mission. Unlike the experimental thruster, the engine would be rated for continuous operation and extensive design work was required to increase the specific thrust by raising the design factor and unloaded Q.
The engine was built with a design factor of 0.844 and has a measured Q of 45,000 for an overall diameter of 280 mm. The microwave source is a water cooled magnetron with a variable output power up to a maximum of 1.2 kW.
To obtain the predicted thrust the engine must maintain stable resonance at this high Q value. Major design challenges have included thermal compensation, tuning control and source matching.
The engine was tested in a large static test rig employing a calibrated composite balance to measure thrust in 3 directions, up, down and horizontal. A total of 134 test runs were carried out over the full performance envelope, with a maximum specific thrust of 214mN/kW being measured.
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