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[专题专项] Emdrive无工质推进:葡萄牙科学家已成功建立相对可靠的

踏实 发表于 2016-10-30 21:55 来自航空航天港手机版! | 显示全部楼层 |阅读模式
Theoretical Physicists Are Getting Closer to Explaining How NASA’s ‘Impossible’ EmDrive Works
The EmDrive propulsion system might be able to take us to the stars, but first it must be reconciled with the laws of physics.
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[size=0.75]Giulio Prisco
[size=0.75]Oct 31 2017, 10:00pm

[size=0.75]Image: Shutterstock
Giulio Prisco is a futurist, theoretical physicist, and computer scientist. He writes about science, technology, and the future. He's also a cofounder of Space Cooperative.
A tentative theoretical explanation for the mysterious, "impossible" EmDrive propulsion system was published in the Journal of Applied Physical Science International in August. First proposed by British engineer Roger Shawyer, the EmDrive is an asymmetric box that looks like a truncated cone, with a standing microwave field inside that—apparently violating known physical laws—seems able to generate thrust and propel the device.

Meanwhile, China's state media claims that the country's scientists have perfected a working EmDrive prototype and are preparing to test it in space. NASA is also funding a feasibility study for an interstellar mission powered by a related exotic propulsion method.
In September 2016, propulsion researchers gathered for a select, invitation-only workshop at an isolated retreat in Estes Park, Colorado. The proceedings and videos of the workshop, sponsored by the Space Studies Institute, are available online.

Later that year, a paper by NASA's Eagleworks team, titled "Measurement of Impulsive Thrust from a Closed Radio-Frequency Cavity in Vacuum," published in the American Institute of Aeronautics and Astronautics (AIAA)'s peer-reviewed Journal of Propulsion and Power, described promising experimental results and hinted at possible theoretical EmDrive models.
The publication of NASA's paper silenced some objections to EmDrive research based on the lack of peer-reviewed publications in top scientific journals. But a more serious debate continues, based on something far more important: the fundamental laws of physics. Some scientists believe EmDrive technology is impossible, because it doesn't seem to adhere to our current understanding of how the universe is supposed to work.
The law of conservation of momentum says there's no way electromagnetic waves bouncing inside a box can push a box forward. Unless, that is, some other physical effect carries momentum away.

Today's reaction-powered spacecraft works like this: Propellant exhaust carries momentum away and generates forward thrust. But the need to carry sufficient propellant is a strong limit for space travel, which makes long-distance space missions expensive to the point of infeasibility.
If the reaction-free EmDrive works, it would open the door for reaction-free space missions, which could reach the planets in weeks instead of months, and at a much lower cost. It could ultimately open a path to the stars. Therefore, it's not surprising that visionary engineers continue to pursue experimental and theoretical EmDrive research, despite the controversial nature of the technology.

In the lab, EmDrive researchers try to conclusively demonstrate that thrust is there. The 2016 NASA paper reports a modest thrust beyond experimental error margins. But this thrust would perform much better, especially for long-distance missions, than a higher thrust on heavier, propellant-based spaceships. In fact, according to the NASA researchers, the EmDrive would outperform other "zero propellant" propulsion systems studied to date, such as light sailing.
Theoretical scientists are trying to understand why and how EmDrive propulsion works. The NASA paper suggests a tentative explanation based on a quantum physics theory, "a nonlocal hidden-variable theory, or pilot-wave theory for short."
A new research paper by a Portuguese scientist, titled "A Possible Explanation for the Em Drive Based on a Pilot Wave Theory" is now trending among EmDrive enthusiasts in the NasaSpaceFlight forum. The paywalled paper proposes a similar model to the NASA one (here's an open access preprint you can read.)

Pilot-wave theories have been proposed since the 1920s by quantum physicists, notably Louis de Broglie and David Bohm, to make sense of the weird behavior of quantum matter. Recently, pilot-wave quantum theories have gained more popularity after it was discovered that pilot-wave quantum-like behavior can be reproduced in classical fluids and explained by classical (non-quantum) fluid dynamics.
[size=0.75]Image: Shutterstock

http://digitalpaper.stdaily.com/ ... t_357004.htm?div=-1



本报记者 操秀英

    EM引擎是英文“Electromagnetic Drive”的简称,指的是一种全新的驱动方式——电磁驱动,由英国工程师罗杰·肖耶2000年左右提出。原理大致是:用电力在密闭的锥形腔内产生微波,微波在腔内来回反射,在两端产生的推力差即可作为飞行器前进的动力,太阳能提供电力来维持微波的运动。



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 楼主| 踏实 发表于 2016-10-30 21:57 来自航空航天港手机版! | 显示全部楼层
惯性推进技术将运用于发射卫星 2016-10-09 14:57 新浪科技 0  收藏    Cannae Inc公司宣称,他们的系统不需要在航天器上安装推进器来产生动力。他们即将开展一项任务,利用该系统把一颗立方体卫星发射到低地球轨道上去。    Cannae引擎系统全靠推进器产生的洛伦兹力(即电磁力)来创造动力。该技术由奎多·费塔(Guido Fetta)发明。今年8月17日,该公司宣布不久便将对该技术展开太空测试。   新浪科技讯 北京时间10月11日消息,据国外媒体报道,长时间以来,全世界的物理学家一直声称“惯性推进”是不可能实现的,但有一家名叫Cannae Inc的公司近日却公布了一项计划,准备用惯性推进技术将航天器送入轨道。    该公司宣称,他们的系统不需要在航天器上安装推进器来产生动力。他们即将开展一项任务,利用该系统把一颗立方体卫星发射到低地球轨道上去。科学家认为,这一概念违反了热力学定律。而如果他们的示范任务取得成功的话,我们对物理的理解将会受到巨大的影响。与假想中的EmDrive引擎相似,Cannae引擎是一套封闭系统,在产生推力的同时,不会产生任何废弃物。该公司还声称,利用该技术,只需十周便可抵达火星。Cannae引擎系统全靠推进器产生的洛伦兹力(即电磁力)来创造动力。    该技术由奎多·费塔(Guido Fetta)发明。今年8月17日,该公司宣布不久便将对该技术展开太空测试。为了启动该任务,Cannae公司还成立了一家新的姐妹公司,名叫Theseus太空有限公司(Theseus Space Inc。)。他们计划用一颗6U(10*20*30cm)立方体卫星来示范该推进器的运作方式。    “Theseus公司将发射一颗立方体卫星,它利用了Cannae推进器技术,因此可以停留在高度低于150英里(约合240公里)的轨道上。“该卫星将在低地球轨道上最少停留6个月时间。此次任务的主要目标是,在地球轨道上演示我们的推进技术。该任务的第二大目标是,由Cannae推进器技术实现轨道高度和倾斜角变换。”    如果这一类系统取得成功的话,卫星行业将会发生革命性的变化。推进器占了卫星重量的很大一部分,而且限制了卫星的性能。但如果Cannae引擎能够发挥作用的话,就可以改变这一局面了。“Cannae推进技术对于小型卫星任务来说格外有用,因为它们发射时需要的能量更小,质量和体积也更小。Theseus公司发射的立方体卫星上的推进系统体积预计不超过1.5U,需要的能量不超过10瓦特。”    该公司尚未宣布开展该任务的具体时间。此外,还有其它创新公司也在研发类似的系统,该公司还面临着来自这些公司的竞争。上月,NASA有关该技术的一篇论文已经被提交给了同行评审。但在这些系统真正地证明自己的能力之前,物理学家仍对它们持怀疑态度。
topzdx 发表于 2016-10-30 23:27 | 显示全部楼层
只靠 10W的电力,有没说推力多少? 推重比呢?(卫星重量是多少)?
zimu 发表于 2016-10-30 23:36 | 显示全部楼层

SEPTEMBER 26, 2016


查了下, 这次发射的6U卫星并不使用所谓的EM推进器, 公司首页挂了个澄清说明出来.

There has been a lot of erroneous information in media articles regarding Cannae’s upcoming launch of a cubesat mission into LEO. To clarify our previous post and press release: Cannae is not using an EmDrive thruster in our upcoming launch. Cannae is using it’s own proprietary thruster technology which requires no on-board propellant to generate thrust. In addition, this project is being done as a private venture. Cannae is only working with our private commercial partners on the upcoming mission.

使用的是不使用星载推进剂的推进器. 估计是捕获高空带电离子再加速来获得推力.
snowtiger 发表于 2016-10-30 23:56 来自航空航天港手机版! | 显示全部楼层
zimu 发表于 2016-10-30 23:36
SEPTEMBER 26, 2016


 楼主| 踏实 发表于 2016-10-31 12:08 | 显示全部楼层
zimu 发表于 2016-10-30 23:36
SEPTEMBER 26, 2016


跟EM 是一样的原理。
 楼主| 踏实 发表于 2016-10-31 12:09 | 显示全部楼层
topzdx 发表于 2016-10-30 23:27
只靠 10W的电力,有没说推力多少? 推重比呢?(卫星重量是多少)?

topzdx 发表于 2016-10-31 13:49 | 显示全部楼层
踏实 发表于 2016-10-31 12:09



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 楼主| 踏实 发表于 2016-10-31 15:12 | 显示全部楼层
topzdx 发表于 2016-10-31 13:49

6U的卫星 约30KG出头,轨道维持,看周围电磁环境和微粒子,高能粒子的冲击。哪怕只有0.1mN都是非常了不起的了。
楠宫晓风vn 发表于 2016-10-31 15:47 | 显示全部楼层
本帖最后由 楠宫晓风vn 于 2016-10-31 15:54 编辑

Cannae Corporation was formed to commercialize our breakthrough Cannae-Drive propulsion technologies. Our thrusters provide dramatically improved performance and economics for space-based applications.

The core of our technologies use the Lorentz force imbalances generated by our thrusters   to generate thrust without requiring on-board propellant. Multiple tests of the Cannae-Drive thrusters have demonstrated force-generation without the use of on-board propellant. Cannae continues to develop and demonstrate Cannae-Drive technology at our state-of-the-art research and development laboratory located outside of Philadelphia, PA.

All thruster designs depicted on this website have patent-pending status.

楠宫晓风vn 发表于 2016-10-31 15:56 | 显示全部楼层
踏实 发表于 2016-10-31 12:09

xingzheshengcun 发表于 2016-10-31 16:18 | 显示全部楼层

磁力帆 推进技术 应用得如何?
zimu 发表于 2016-10-31 18:38 | 显示全部楼层

以6U卫星的尺度, 外太空的地球磁场基本 就是匀强磁场, 闭合电路在匀强磁场中通电如何获得推力.除非这货能靠精确调姿利用外层大气的影响来维持姿态, 进而靠那么最多6U高度的的地磁场降来获得不平衡电磁力.
立体派 发表于 2016-10-31 23:00 | 显示全部楼层
鱼肉百姓馆 发表于 2016-11-13 21:51 | 显示全部楼层


英国SPR公司向第64届北京国际宇航大会提交了一篇论文The Dynamic Operation of a High Q EmDrive Microwave Thruster",对高温超导材料制作的无工质微波推进腔进行了初步测试,具体实验数据整理成论文,据其内容显示目前测量获得的最高功推比已达到176N/KW,测试条件为70K以下,Q值达到10的7次方,该公司只公布相关测试数值与曲线,但并未公开推力器视频与图片。



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Jyahway 发表于 2016-11-14 03:19 | 显示全部楼层
DF21 发表于 2016-11-14 10:22 | 显示全部楼层
Jyahway 发表于 2016-11-19 14:37 | 显示全部楼层
本帖最后由 Jyahway 于 2016-11-18 23:38 编辑

peer-reviewed paper, Measurement of Impulsive Thrust from a Closed Radio-Frequency Cavity in Vacuum
Jyahway 发表于 2016-11-19 14:47 | 显示全部楼层
有个人试图解释em drive,但是有两个假设很难消化
 楼主| 踏实 发表于 2016-11-20 14:44 | 显示全部楼层
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