Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New thruster design increases efficiency for future spaceflight

16.08.2017

Inlet nozzles create vortex to power plasma ejection

Hall thrusters (HTs) are used in earth-orbiting satellites, and also show promise to propel robotic spacecraft long distances, such as from Earth to Mars. The propellant in a HT, usually xenon, is accelerated by an electric field which strips electrons from neutral xenon atoms, creating a plasma. Plasma ejected from the exhaust end of the thruster can deliver great speeds, typically around 70,000 mph.


This is the vortex exhaust mode on low-power cylindrical Hall thruster.

Credit: Wei Liqiu, Harbin Institute of Technology, China

Cylindrical shaped Hall thrusters (CHTs) lend themselves to miniaturization and have a smaller surface-to-volume ratio that prevents erosion of the thruster channel. Investigators at the Harbin Institute of Technology in China have developed a new inlet design for CHTs that significantly increases thrust. Simulations and experimental tests of the new design are reported this week in the journal Physics of Plasmas, by AIP Publishing.

CHTs are designed for low-power operations. However, low propellant flow density can cause inadequate ionization, a key step in the creation of the plasma and the generation of thrust. In general, increasing the gas density in the discharge channel while lowering its axial velocity, i.e., the speed perpendicular to the thrust direction, will improve the thruster's performance.

"The most practical way to alter the neutral flow dynamics in the discharge channel is by changing the gas injection method or the geometric morphology of the discharge channel," said Liqiu Wei, one of the lead authors of the paper.

The investigators tested a simple design change. The propellant is injected into the cylindrical chamber of the thruster by a number of nozzles that usually point straight in, toward the center of the cylinder. When the angle of the inlet nozzles is changed slightly, the propellant is sent into a rapid circular motion, creating a vortex in the channel.

Wei and his coworkers simulated the motion of the plasma in the channel for both nozzle angles using modeling and analysis software (COMSOL) that uses a finite element approach to modeling molecular flow. The results showed that the gas density near the periphery of the channel is higher when the nozzles are tilted and the thruster is run in vortex mode. In this mode, gas density is significantly higher and more uniform, which also helps improve thruster performance.

The investigators verified their simulation's predictions experimentally, and the vortex inlet mode successfully produced higher thrust values, especially when a low discharge voltage was used. In particular, the specific impulse of the thruster increased by 1.1 to 53.5 percent when the discharge voltage was in the range of 100 to 200 Volts.

"The work we report here only verified the practicability of this gas inlet design. We still need to study the effect of nozzle angle, diameter, the ratio of depth to diameter and the length of the discharge channel," Wei said. He went on to predict that the vortex design will be tested in flight-type HTs soon and may eventually be used in spaceflight.

###

The article, "Effect of vortex inlet mode on low-power cylindrical Hall thruster," is authored by Yongjie Ding, Boyang Jia, Yu Xu, Liqiu Wei, Hongbo Su, Peng Li, Hezhi Sun, Wuji Peng, Yong Cao and Daren Yu. The article will appear in the journal Physics of Plasmas August 15, 2017 [DOI: 10.1063/1.4986007]. After that date, it can be accessed at http://aip.scitation.org/doi/full/10.1063/1.4986007.

ABOUT THE JOURNAL

Physics of Plasmas is devoted to the publication of original experimental and theoretical work in plasma physics, from basic plasma phenomena to astrophysical and dusty plasmas. See http://pop.aip.org.

Media Contact

Julia Majors
media@aip.org
301-209-3090

 @AIPPhysicsNews

http://www.aip.org 

Julia Majors | EurekAlert!

Further reports about: Plasmas diameter injection method nozzles plasma physics propellant spaceflight xenon

More articles from Physics and Astronomy:

nachricht Enhancing the quantum sensing capabilities of diamond
23.11.2017 | The Hebrew University of Jerusalem

nachricht Quantum optics allows us to abandon expensive lasers in spectroscopy
22.11.2017 | Lomonosov Moscow State University

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Frictional Heat Powers Hydrothermal Activity on Enceladus

Computer simulation shows how the icy moon heats water in a porous rock core

Heat from the friction of rocks caused by tidal forces could be the “engine” for the hydrothermal activity on Saturn's moon Enceladus. This presupposes that...

Im Focus: Nanoparticles help with malaria diagnosis – new rapid test in development

The WHO reports an estimated 429,000 malaria deaths each year. The disease mostly affects tropical and subtropical regions and in particular the African continent. The Fraunhofer Institute for Silicate Research ISC teamed up with the Fraunhofer Institute for Molecular Biology and Applied Ecology IME and the Institute of Tropical Medicine at the University of Tübingen for a new test method to detect malaria parasites in blood. The idea of the research project “NanoFRET” is to develop a highly sensitive and reliable rapid diagnostic test so that patient treatment can begin as early as possible.

Malaria is caused by parasites transmitted by mosquito bite. The most dangerous form of malaria is malaria tropica. Left untreated, it is fatal in most cases....

Im Focus: A “cosmic snake” reveals the structure of remote galaxies

The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.

Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...

Im Focus: Visual intelligence is not the same as IQ

Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.

That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...

Im Focus: Novel Nano-CT device creates high-resolution 3D-X-rays of tiny velvet worm legs

Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.

During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Ecology Across Borders: International conference brings together 1,500 ecologists

15.11.2017 | Event News

Road into laboratory: Users discuss biaxial fatigue-testing for car and truck wheel

15.11.2017 | Event News

#Berlin5GWeek: The right network for Industry 4.0

30.10.2017 | Event News

 
Latest News

Underwater acoustic localization of marine mammals and vehicles

23.11.2017 | Information Technology

Enhancing the quantum sensing capabilities of diamond

23.11.2017 | Physics and Astronomy

Meadows beat out shrubs when it comes to storing carbon

23.11.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>