News Plasma propulsion for aircraft and spacecraft.

[RGClark]

Plasma propulsion could eventually become effective and useful for higher altitude aviation, airships and eventually space access.
brian wang | May 20, 2017
http://www.nextbigfuture.com/2017/0...ion-airships-and-eventually-space-access.html

As discussed in a comment to this article by Professor Jason Cassidry, the problem is the huge power requirements for this propulsion method, magnetoplasma propulsion.

This may be solvable by using electrodes at the nanoscale. In another plasma propulsion method, electrohydrodynamic propulsion (EHD), this can reduce the power requirements:

Carbon nanotubes for "Ionic Wind" Craft or "Ionocraft".
Clark R*
Department of Mathematics, Widener University, USA
Review Article
Volume 1 Issue 2 / Received Date: September 26, 2016 / Published Date:
October 20, 2016
Keywords: Electrohydrodynamic propulsion; Carbon nanotubes; Nanowires; Ionic wind; Ionocraft; Plasma drive
https://medwinpublishers.com/NNOA/volume.php?volumeId=23&issueId=63


Bob Clark

 

[RGClark]

MIT published research on a prototype model airplane using “ionic wind” propulsion:

Ion drive meets drone, as small plane flies with no moving parts.
A solid-state propulsion system works by ionizing the air.
JOHN TIMMER - 11/21/2018, 1:58 PM

https://arstechnica.com/science/2018/11/small-drone-soars-on-an-ionic-wind-with-no-moving-parts/

It however was only able to fly for about a minute on battery power. The researchers want to increase power density and therefore flight time. But it’s already known how this can be done, by using wiring at the nanoscale. You would then get a practical vehicle capable of heavy payloads:

https://www.researchgate.net/project/Carbon-nanotubes-for-ionic-wind-craft-or-ionocraft

Edit: it was actually able to fly only for seconds under it's own power, before the batteries were drained, which shows the importance of increasing the power density.

Bob Clark

 

[Gerdih]

Did you get access to the MIT paper? Honestly, I can't see how ionocraft could be used to propel heavy loads. I have read the team is quite confident they could increase the efficency of the system to 15%. That doesn't sound enough though. I have seen no mention of nanotubes.

As far as I know the only remarkable thing the team did was managing to fit a 40kV battery inside a 2,5kg glider.

From: https://arstechnica.com/science/2018/11/small-drone-soars-on-an-ionic-wind-with-no-moving-parts/

"Still, the researchers have a huge list of potential improvements. The current design was limited by the decision to keep it flying inside the track at MIT. Allowing larger wings and a higher speed could get that efficiency up to five percent without any changes to the underlying technology. They also plan to explore things like different ways of generating ions, electrode designs that reduce drag and/or are integrated into the wing, and better power conversion electronics, all of which could boost things further."

This sounds as: We will investigate how to improve stirling engines by improving bearings

 

[RGClark]

The new method that needs to be tested is electrodes or ionizing wires at the nanoscale. This is described simply here:

Ion drive for aircraft imminent.
Started by Robert Clark ● November 1, 2016
https://www.electronics-related.com/showthread/sci.electronics.design/586769-9.php

The basic explanation is that for wires at the nanoscale the voltage needed to create the required ionization instead of being ca. 40,000 volts as it is now might only be a few tens to hundreds of volts. This results in greatly reduced power requirements for the thrust produced.

Bob Clark

 

[Urwumpe]

For wires at nanoscale, the voltage for pushing electrons through them are much higher as well, remember that conductance decreases with diameter

Also, carbon nanowires don't react too well on being heating with oxygen around... or be illuminated by UV radiation...

 

[EthanKrauss]

Dr. Clark was actually on the right track! Instead of using lower voltage with ultrathin wires though, you use higher voltage with really low current. Thinner wires produce more ion thrust with less current! Higher voltages are also more efficient for this type of propulsion. Please google the "Self Contained Ion Powered Aircraft," there are 9 flight videos of it online, with the power supply onboard! It is patented for carrying its power supply with VTOLs, and well verified to predated any other such device! On close inspection you will see that this is correct...