MIT's Ion-drive sustainer takes flight

[son_of_flubber]

https://techxplore.com/news/2018-11-first-ever-plane.html

[son_of_flubber]

https://phys.org/news/2013-04-thrusters-powered-ionic-efficient-alternative.html

[teck48[_2_]]

This was a cover story in popular mechanics in the mid sixties. A gentleman named De Seversky I think. I started building one planning to figure out how to use a van de graf generator to provide the ~100K volts. My parents weren’t too enthused...

[Dan Marotta]

Or something like this: https://en.wikipedia.org/wiki/Project_Pluto

And it wouldn't even need those nasty batteries!

On 11/22/2018 7:33 AM, son_of_flubber wrote:
> https://techxplore.com/news/2018-11-first-ever-plane.html
>

--
Dan, 5J

[Charlie M. (UH & 002 owner/pilot)]

I saw that on a car forum. While interesting, I wish they had a RC modeler help with rigging the craft. I also wonder how much the launch device added to the flight distance......basically, would it have gone close to as far just due to the launch?

[Martin Gregorie[_6_]]

On Thu, 22 Nov 2018 09:59:05 -0800, Charlie M. (UH & 002 owner/pilot)
wrote:

> I saw that on a car forum. While interesting, I wish they had a RC
> modeler help with rigging the craft. I also wonder how much the launch
> device added to the flight distance......basically, would it have gone
> close to as far just due to the launch?

I'd guess they had model fliers involved: the wing looks very much like a
free flight model wing and looks to be about the same size (2.5m span) as
a modern F1A wing and the flying speed looks similar to an F1A as well.

I looked for a launcher but couldn't see one, so maybe it was hand
launched. That would be easy enough: use a timer to turn on the high
voltage after its 1-2 meters away from the launcher. The launch looked
nice and smooth, which also points to a model flyer doing it.

Also, MIT is Mark Drela's home territory: he's long been heavily involved
in RC soaring and low speed aerodynamics and is the man behind X-Foil.


--
Martin | martin at
Gregorie | gregorie dot org

[Luke Scharf]

On Thursday, November 22, 2018 at 12:59:07 PM UTC-5, Charlie M. (UH & 002 owner/pilot) wrote:
> I saw that on a car forum. While interesting, I wish they had a RC modeler help with rigging the craft. I also wonder how much the launch device added to the flight distance......basically, would it have gone close to as far just due to the launch?

Here are two papers from Steven Barrett on the topic:
http://rspa.royalsocietypublishing.org/content/471/2175/20140912
http://rspa.royalsocietypublishing.org/content/469/2154/20120623.short

They're from 2013 and 2015, so they may not answer any questions about this specific demonstration. I imagine that Dr. Barrett is working on publishing another paper which should answer those questions directly.

-Luke

[Charlie M. (UH & 002 owner/pilot)]

Wen it flies off the ramp, look for the long black bungee (20' or so long) that is visible at the top of the ramp.

[Martin Gregorie[_6_]]

On Thu, 22 Nov 2018 15:11:04 -0800, Charlie M. (UH & 002 owner/pilot)
wrote:

> Wen it flies off the ramp, look for the long black bungee (20' or so
> long) that is visible at the top of the ramp.

Thanks: I missed that, at least partly because I couldn't stop the first
video on https://techxplore.com/news/2018-11-first-ever-plane.html and
didn't think to watch the second one, which shows a lot of launches from
directly behind the test aircraft.


--
Martin | martin at
Gregorie | gregorie dot org

[teck48[_2_]]

https://images-na.ssl-images-amazon.com/images/I/81rLxOEb5fL._SY445_.jpg

[Dan Marotta]

That looks pretty sweet!Â* No rotors below to chop you up should you fall
off.Â* But, is that a fast breeder reactor that he's standing on?Â* It
would be great to be able to sell the excess plutonium to the
utilities.Â* Talk about "off the grid"!

On 11/23/2018 5:32 AM, teck48 wrote:
> https://images-na.ssl-images-amazon.com/images/I/81rLxOEb5fL._SY445_.jpg

--
Dan, 5J

[Frank Whiteley]

On Friday, November 23, 2018 at 10:13:29 AM UTC-7, Dan Marotta wrote:
> That looks pretty sweet!Â* No rotors below to chop you up should you fall
> off.Â* But, is that a fast breeder reactor that he's standing on?Â* It
> would be great to be able to sell the excess plutonium to the
> utilities.Â* Talk about "off the grid"!
>
> On 11/23/2018 5:32 AM, teck48 wrote:
> > https://images-na.ssl-images-amazon.com/images/I/81rLxOEb5fL._SY445_.jpg
>
> --
> Dan, 5J

Local communities might become independent and 'off the grid' using thorium reactors (developed at Los Alamos) but AFAIK, the NRC has not made deployment possible in the US. https://en.wikipedia.org/wiki/Thorium-based_nuclear_power

[Dave Walsh]

So a solution that has LiIon batteries AND 40,000 volts flying
around: what could possibly go wrong?
I'm guessing the currents involved are very low?
Would a human being survive the encounter?

>

[Martin Gregorie[_6_]]

On Sat, 24 Nov 2018 10:50:25 +0000, Dave Walsh wrote:

> So a solution that has LiIon batteries AND 40,000 volts flying around:
> what could possibly go wrong?
> I'm guessing the currents involved are very low?
> Would a human being survive the encounter?
>
Currents won't be low for a full-size aircraft even if the claimed
efficiency of the ion-drive, in terms of thrust/watt, is much higher than
a modern jet engine, i.e. 5-10 times better.

A good idea of the power needed to fly a commuter jet is shown by a joint
Rolls Royce/ British Aerospace project. This will convert a BA.146 to
partial electric power. This involves replacing two of its jet engines
with electric ducted fans, which will initially be powered from a 2MW gas
turbine generator installed in the rear fuselage, which shows that the
power requirements of a regional jet is a few megawatts. Now assume that
the electric ducted fan has a similar efficiency to the jet engine it
replaces. IOW replacing with an ion-jet rig drops the power requirement
by a factor of 10, but its still in the several hundred kilowatt
ballpark.

My point? Even if voltages are in the KV region, so are currents when
hundreds of kilowatts are involved.

What we *really* need is the traditional Science Fiction Thruster unit -
and the Rotax-sized fusion reactor that powers it.


--
Martin | martin at
Gregorie | gregorie dot org

[[email protected]]

> What we *really* need is the traditional Science Fiction Thruster unit -
> and the Rotax-sized fusion reactor that powers it.

Got it, Martin!

https://www.youtube.com/watch?v=ptlhgFaB89Y

[john firth]

On Thursday, November 22, 2018 at 9:33:17 AM UTC-5, son_of_flubber wrote:
> https://techxplore.com/news/2018-11-first-ever-plane.html

Has anyone quoted or attempted to assess efficiency?

John F

[son_of_flubber]

On Saturday, November 24, 2018 at 11:11:04 AM UTC-5, john firth wrote:
> On Thursday, November 22, 2018 at 9:33:17 AM UTC-5, son_of_flubber wrote:
> > https://techxplore.com/news/2018-11-first-ever-plane.html
>
> Has anyone quoted or attempted to assess efficiency?
>
> John F

Look at the links posted by Luke Scharf above

[Martin Gregorie[_6_]]

On Sat, 24 Nov 2018 06:44:55 -0800, markmocho53 wrote:

>> What we *really* need is the traditional Science Fiction Thruster unit
>> -
>> and the Rotax-sized fusion reactor that powers it.
>
> Got it, Martin!
>
> https://www.youtube.com/watch?v=ptlhgFaB89Y

Yep - though I'd been thinking more of the pics on the covers of old SF
mags. You know the ones I mean - where all buildings had streamlined
cooling fins and the spacegirls all carried blasters (with fins on them)
and wore bikinis under their transparent space suits. Larry Niven's
"Ringworld" and his 'Known Space' stories hit that spot too.


--
Martin | martin at
Gregorie | gregorie dot org