NASA confirms performance "impossible" wave motor without using reaction mass - EmDrive

Disclaimer: This article is written by non-specialist in this field. Korrektivrovki comments and deployed comments are welcome. I>

The essence of the news h4> July 30 at 50th AIAA / ASME / SAE / ASEE Joint Propulsion Conference - fiftieth joint conference of the American Institute of Aeronautics and Astronautics, the American Society of Mechanical Engineers, the Community of Automotive Engineers and the American Society for Engineering Education, dedicated to motor systems, if anyone interested value cuts, representatives Laboratory NASA provided the report, according to which EmDrive, the engine produces thrust without the ejection of reactive mass works.

How it works h4> Obviously, the reader, following the example of the global scientific community, skeptical eyebrow arches relative to the previous sentence. Because immediately bring description of the principle of operation of the engine , presented on the website of the company and inventor.


In the most general form of the device consists of a magnetron and reflective chamber specific forms created by the resonance of electromagnetic waves. I>

The principle of operation is based on the effect of the pressure of electromagnetic radiation: microwave radiation exerts pressure on the reflector. Due to the shape of the reflection chamber pressure at b on i> proc eed side is higher than on the smaller. There is a logical objection that, according to Newtonian laws, such pressure in a closed system will only lead to stress on the material of the camera. However, according to the authors, in this case, you must use special relativity, according to which, due to near-light speed wave reflectivity camera and wave to be considered in different reference systems and, therefore, the combination of reflector + wave becomes an open system and creates cravings without the use of jet ejection. The strength of the wave is further increased thanks to the created resonance. Interests of specific formulas can see them in the above source.

History h4> The first experimental sample: copper colored reflective chamber, the magnetron and a lot of water cooling. I>

The first news of this engine appeared in 2000, when the Briton Roger J. Shawyer founded Satellite Propulsion Research Ltd, engaged in the development of this device. Despite the fact that a working prototype was made back in 2003 (a device created traction in subtle but sufficient to prove the efficiency of the concept of 16 mN), complete independent studies were initiated only in 2008 - then the Chinese team of scientists conducted theoretical calculations and agreed that the theory is viable. In 2010, the same team published a paper in which derived a formula for calculating the thrust of the engine, and also stated that in the experiments was obtained Rod 720 mN (72 grams). However, their work was met with great skepticism.

Finally, a scientist from the US, Guido Fetta, built his version "without fuel" engine operating on the same principle, but uses no form reflector camera and reflectors with different reflectance, and persuaded NASA to test.

Laboratory test results Eagleworks Laboratories were presented on July 30 2014. The general sense of the report can be compressed to a "We're not sure, how i> it works, but it works": the researchers tried to avoid thinking about the physics of the engine and just brought the test results. Excerpt from report .

For reliability testing laboratory staff conducted a comparative test of "zero engine" - the same system that is configured with minor changes, prevents traction, as well as working sample was tested in different directions to avoid possible errors due to the influence of electromagnetic fields on the measuring equipment.

According to the report NASA, achieved traction in 30-50 mN. Much smaller than previously claimed result of the Chinese team, but quite enough to confirm the functionality of the system. Unfortunately, the amount of electricity consumed was not specified, so to evaluate the effectiveness of such an engine does not go.

Sources of information: раз and two .

Possible application h4> The following text is the author's reflections only i>

I think any enthusiast space technology can bring many possible situations where such an electric motor will be extremely useful. First of all - the satellite is in a high earth orbit. Now b on i> most of the weight is sent to geostationary orbit apparatus consists of fuel. Using EmDrive, the device can reach the higher orbit, getting energy from solar panels or RTG.

A similar system can be used for the study of the solar system - moving with constant, though slight acceleration, the spacecraft will be able to cover the interplanetary distances much faster than using a modern system of "initial kick" from chemical rockets and ballistic flight.

A similar system offering ion engines, but, firstly, they still used working fluid, and hence the amount that imposes restrictions on the total amount of thrust which the motor can produce, not to mention the fact that the fuel is ground. Second, judging by what he saw, EmDrive design much easier and cheaper ion engine: reflective chamber, the magnetron, the power source and cooling system - all these parts are simple enough and long tested.

Of course, so far we are talking only about the extremely lightweight devices - remains to be seen whether it is possible to create an engine with a thrust sufficient that it can be installed on the machine or manned spacecraft sized interplanetary module Curiosity. However, if it still will be possible, the only limitation in interplanetary flights would be energy, and in contrast to the fuel to produce it in the space we already know.

Source: habrahabr.ru/post/232093/

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