密歇根技术大学机械工程博士候选人布兰登·杰克逊（Brandon Jackson）使用离子液体铁氟利（Ionic Liquid Ferrofluid）创建了一种新的电喷雾推进器计算模型，这是一种有前途的技术，用于通过太空推动小型卫星。具体而言，杰克逊着眼于模拟电喷雾启动动力学。换句话说，是什么赋予了铁氟烯特征的尖峰。
他是最近一篇文章的首席作者液体的物理学, “Ionic Liquid Ferrofluid Interface Deformation and Spray Onset Under Electric and Magnetic Stresses”.
More than 1,300 active satellites orbit the Earth. Some are the size of a school bus, and others are far smaller, the size of a shoebox or a smart phone.
Small satellites can now perform the missions of much larger and more expensive spacecraft, due to advances in satellite computational and communications systems. However, the tiny vehicles still need a more efficient way to maneuver in space.
像在大型卫星上部署的等离子推进器一样，缩小的等离子体推进器无法正常工作。微刺的一种更有希望的方法是电喷雾。
Electrospray involves microscopic, hollow needles that use electricity to spray thin jets of fluid, pushing the spacecraft in the opposite direction. But the needles have drawbacks. They are intricate, expensive and easily destroyed.
为了解决这个问题，密歇根理工学院太空系统的L. Brad King，Ron＆Elaine Starr教授正在创建一种新型的微型集团，当受到磁场激动时，它是由自己的推进剂组装而成的。微小的推进器不需要脆弱的针，并且基本上是坚不可摧的。
“We’re working with a unique material called an ionic liquid ferrofluid,” King says, explaining that it’s both magnetic and ionic, a liquid salt. “When we put a magnet underneath a small pool of the ferrofluid, it turns into a beautiful hedgehog structure of aligned peaks. When we apply a strong electric field to that array of peaks, each one emits an individual micro-jet of ions.”
The phenomenon is known as a Rosensweig instability. The peaks also heal themselves and re-grow if they are somehow damaged.
King came up with the idea of using ferrofluids for thrusters in 2012. He was trying to make an ionic liquid that behaved like a ferrofluid when he learned about a research team at the University of Sydney led by Brian Hawkett and Nirmesh Jain. They had developed a ferrofluid from magnetic nanoparticles made by the life sciences company Sirtex.
金在铁氟利样本中的早期工作是纯粹的反复试验和错误。结果很好，但是物理学知之甚少。那时，空军科学研究办公室（AFOSR）赋予了国王一份合同，以研究铁氟烷的流体物理学。
输入杰克逊（Jackson），金（King）建议其博士学位。
“Typically among engineers, there are experimentalists who build and measure things, or there are modelers who simulate things,” King says. “Brandon excels at both.”
杰克逊在国王离子空间推进实验室工作，对铁氟利的界面动力学进行了实验和计算研究，并创建了一个离子液体铁氟烯电喷雾的计算模型。
“We wanted to learn what led up to emission instability in one single peak of the ferrofluid microthruster,” Jackson says, who developed a model for a single peak and conducted rigorous testing to ensure the model was correct.
The team gained a much better understanding of the relationships between magnetic, electric and surface tension stresses. Some of the data gathered through the model surprised them.
“我们知道磁场大的effect in preconditioning the fluid electric stress,” Jackson says, explaining this discovery might lead to a better understanding of the unique behaviors of ferrofluid electrosprays.
The AFOSR recently awarded King a second contract to continue researching the physics of ferrofluids, and he says, “Now we can take what we’ve learned, and instead of modeling a single peak, we’ll scale it up and model multiple peaks.”
Their next set of experiments will be more like a thruster, though a working thruster is still several years away. Although making 100 peaks or more, all thrusting identically, will be much more challenging.
“通常在实验室中，我们会有一个峰值工作，还有99个峰会。布兰登（Brandon）的模型将是未来团队的重要工具。”金说。“如果我们取得成功，我们的推进器将使小型廉价卫星以自己的推进为大量产生。这可以改善遥感，以获得更好的气候建模，或者提供更好的互联网连接，世界上仍有30亿人没有。”
团队也已经开始与胡安菲合作rnandez de la Mora, a professor of mechanical engineering and materials science at Yale University, one of the world’s leading experts in electrospray.
In addition to spacecraft propulsion, ferrofluid electrospray technology could be useful in spectrometry, pharmaceutical production, and nanofabrication. Michigan Tech has a pending patent for the technology.
提交以下：Aerospace + defense
