NASA confirms the performance of the "impossible" wave engine that does not use reactive mass - EmDrive
Disclaimer: This article is written by a layman in the field. Corrections, comments and detailed comments are highly appreciated.
July 30th at the 50th AIAA / ASME / SAE / ASEE Joint Propulsion Conference - the 50th joint conference of the American Institute of Aeronautics and Astronautics, the American Society of Mechanical Engineers, the Society of Automotive Engineers and the American Community of Engineering Education, dedicated to motor systems, if you are interested in the abbreviations, NASA laboratories have reported that EmDrive, the engine that creates thrust without releasing reactive mass, is working.
Obviously, the reader, following the example of the world scientific community, skeptically arches his eyebrow regarding the previous phrase. Because here I will give a description of the principle of operation of the engine , presented on the website of the company-inventor.
In the most general form, the device consists of a magnetron and a reflective chamber of a specific form, creating a resonance of an electromagnetic wave.
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The principle of operation is based on the effect of electromagnetic radiation pressure: microwave radiation puts pressure on the reflector. Due to the shape of the reflective chamber, the pressure on the larger side is higher than on the smaller side. There is a logical objection that, according to Newtonian laws, such pressure in a closed system will only lead to a load on the material of the chamber. However, according to the creators, in this case it is necessary to use the Special Theory of Relativity, according to which, due to the near-light speed of a wave, the reflection chamber and the wave should be considered in different reference systems and, therefore, the combination reflector + wave becomes an open system and creates traction without the use of jet release. The wave power is additionally increased due to the created resonance. Those interested in specific formulas can see them in the above source.
The first experimental sample: a copper-colored reflective chamber, a magnetron and a lot of water cooling.
The first news about this engine appeared in 2000, when the British Roger J. Shawyer founded the company Satellite Propulsion Research Ltd, engaged in the development of this device. Despite the fact that the working prototype was made back in 2003 (the device created a barely noticeable, but sufficient for proving the efficiency of the concept 16 mN), full-fledged independent research was started only in 2008 - then the Chinese team of scientists carried out theoretical calculations and agreed that theory is viable. In 2010, the same team published the work, where it derived a formula for calculating the thrust of such an engine, and also stated that the experiments produced thrust of 720 mN (72 grams). However, their work was met with great skepticism.
Finally, a scientist from the USA, Guido Fetta, built his version of a “fuel-free” engine working on the same principle, but not using the shape of a camera reflector, but reflectors with different reflectance, and persuaded NASA to carry out the tests.
The test results of the Eagleworks Laboratories laboratory were presented on July 30, 2014. The general meaning of the report can be compressed to "We are not sure how it works, but it works": the researchers tried to avoid thinking about the physics of the engine and just gave the test results. Excerpt from the report .
For reliability tests, laboratory staff conducted a comparative test of the “zero engine” - the same system, configured with minor changes to prevent the emergence of thrust, and also tested the working sample in different directions to eliminate possible errors caused by the electromagnetic field on the measuring equipment.
According to a NASA report, a thrust of 30-50 mN was achieved. Noticeably less than the previously announced result of the Chinese team, however, it is quite enough to confirm the functionality of such a system. Unfortunately, the amount of electricity consumed was not indicated, so it’s not yet possible to evaluate the efficiency of such an engine.
Sources of information: one and two .
Further text is solely copyright thoughts.
I think any space technology enthusiast will be able to bring many possible situations where such an electric motor will be extremely useful. In the first place - the output of satellites to high Earth orbit. Now most of the mass sent to the geostationary orbit apparatus consists of fuel. With the use of EmDrive, the device can reach a high orbit, receiving energy from solar panels or RTGs.
A similar system can also be used to study the solar system - moving with constant, albeit small acceleration, the spacecraft can cover interplanetary distances much faster than using a modern “initial kick” system from a chemical rocket and a ballistic flight.
A similar system is offered by ionic engines, but, first, they still use a working body, which means that its number imposes restrictions on the total amount of thrust that the engine can produce, not to mention that the fuel has mass. Secondly, judging by what he saw, the design of the EmDrive is much simpler and cheaper than the ion engine: a reflective chamber, a magnetron, an energy source and a cooling system — all these parts are fairly simple and have been tested for a long time.
Of course, so far we are talking only about extremely light vehicles - it is not yet known whether it will be possible to create an engine with sufficient force so that it can be installed on a manned spacecraft or a device the size of an interplanetary Curiosity module. However, if it still turns out to be possible, the only restriction in interplanetary flights will be energy, and, unlike fuel, we are already able to mine it in space.
The essence of the news
July 30th at the 50th AIAA / ASME / SAE / ASEE Joint Propulsion Conference - the 50th joint conference of the American Institute of Aeronautics and Astronautics, the American Society of Mechanical Engineers, the Society of Automotive Engineers and the American Community of Engineering Education, dedicated to motor systems, if you are interested in the abbreviations, NASA laboratories have reported that EmDrive, the engine that creates thrust without releasing reactive mass, is working.
Principle of operation
Obviously, the reader, following the example of the world scientific community, skeptically arches his eyebrow regarding the previous phrase. Because here I will give a description of the principle of operation of the engine , presented on the website of the company-inventor.
In the most general form, the device consists of a magnetron and a reflective chamber of a specific form, creating a resonance of an electromagnetic wave.
')
The principle of operation is based on the effect of electromagnetic radiation pressure: microwave radiation puts pressure on the reflector. Due to the shape of the reflective chamber, the pressure on the larger side is higher than on the smaller side. There is a logical objection that, according to Newtonian laws, such pressure in a closed system will only lead to a load on the material of the chamber. However, according to the creators, in this case it is necessary to use the Special Theory of Relativity, according to which, due to the near-light speed of a wave, the reflection chamber and the wave should be considered in different reference systems and, therefore, the combination reflector + wave becomes an open system and creates traction without the use of jet release. The wave power is additionally increased due to the created resonance. Those interested in specific formulas can see them in the above source.
Story
The first experimental sample: a copper-colored reflective chamber, a magnetron and a lot of water cooling.
The first news about this engine appeared in 2000, when the British Roger J. Shawyer founded the company Satellite Propulsion Research Ltd, engaged in the development of this device. Despite the fact that the working prototype was made back in 2003 (the device created a barely noticeable, but sufficient for proving the efficiency of the concept 16 mN), full-fledged independent research was started only in 2008 - then the Chinese team of scientists carried out theoretical calculations and agreed that theory is viable. In 2010, the same team published the work, where it derived a formula for calculating the thrust of such an engine, and also stated that the experiments produced thrust of 720 mN (72 grams). However, their work was met with great skepticism.
Finally, a scientist from the USA, Guido Fetta, built his version of a “fuel-free” engine working on the same principle, but not using the shape of a camera reflector, but reflectors with different reflectance, and persuaded NASA to carry out the tests.
The test results of the Eagleworks Laboratories laboratory were presented on July 30, 2014. The general meaning of the report can be compressed to "We are not sure how it works, but it works": the researchers tried to avoid thinking about the physics of the engine and just gave the test results. Excerpt from the report .
For reliability tests, laboratory staff conducted a comparative test of the “zero engine” - the same system, configured with minor changes to prevent the emergence of thrust, and also tested the working sample in different directions to eliminate possible errors caused by the electromagnetic field on the measuring equipment.
According to a NASA report, a thrust of 30-50 mN was achieved. Noticeably less than the previously announced result of the Chinese team, however, it is quite enough to confirm the functionality of such a system. Unfortunately, the amount of electricity consumed was not indicated, so it’s not yet possible to evaluate the efficiency of such an engine.
Sources of information: one and two .
Possible use
Further text is solely copyright thoughts.
I think any space technology enthusiast will be able to bring many possible situations where such an electric motor will be extremely useful. In the first place - the output of satellites to high Earth orbit. Now most of the mass sent to the geostationary orbit apparatus consists of fuel. With the use of EmDrive, the device can reach a high orbit, receiving energy from solar panels or RTGs.
A similar system can also be used to study the solar system - moving with constant, albeit small acceleration, the spacecraft can cover interplanetary distances much faster than using a modern “initial kick” system from a chemical rocket and a ballistic flight.
A similar system is offered by ionic engines, but, first, they still use a working body, which means that its number imposes restrictions on the total amount of thrust that the engine can produce, not to mention that the fuel has mass. Secondly, judging by what he saw, the design of the EmDrive is much simpler and cheaper than the ion engine: a reflective chamber, a magnetron, an energy source and a cooling system — all these parts are fairly simple and have been tested for a long time.
Of course, so far we are talking only about extremely light vehicles - it is not yet known whether it will be possible to create an engine with sufficient force so that it can be installed on a manned spacecraft or a device the size of an interplanetary Curiosity module. However, if it still turns out to be possible, the only restriction in interplanetary flights will be energy, and, unlike fuel, we are already able to mine it in space.
Source: https://habr.com/ru/post/232093/
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