MHD in Air

Sort of like a rail gun but with plasma? I like it!

Oh so many acronyms when you get into ion thruster theory and technology.

Ok, before we start - MPD (or MPDT) is a Magnetoplasmadynamic thruster, HET is a Hall effect thruster, what is MHD?

Well this is just cool...

Thanks... Care to guess what my 16 year old son and I are going to build?

I just showed him your video, he smirked and said "cool, how soon?" Tomorrow I order parts.......

Sounds like fun....I think I would modify the projectile....

Another fun project....and cheap too....

1) Not any guidance on how to get that nozzle absolutely concentric by hand drilling. Certainly wouldn't want any built-in side thrust.

2) No mention of the fuse to ignite the mixture.

When young, I was great fan of Jetex reusable, solid fuel rocket motors. They had their ignition problems and used a very thin, fragile wick with a copper wire core. I still have some Jetex motors and the fuel pellets (nitroguanidine), but all the igniting wick has long since deteriorated. Hard to think of a way to ignite the pellets via a very small nozzle. They were a slow ignite, slow burn fuel.

Just as well, you'll put your eye out!

Bizarre remark. And the reason ........ ?

Word of caution , one Jet X contained inside any glass bottle will shatter it and send pieces into you.

I think you will find that you are talking about something completely different. Jetex and Jet X - two different things. Glass bottle? What on earth ........ ?

Estes rocket motors I had as a child used a thin pyrophoric coating on a thin wire, used a 12V battery for ignition. It was similar to the stuff used in "sparkler" firework. Maybe magnesium coated with some sort of protective layer that burned off when the wire got hot.

I sometimes think he gets these ideas from :

I have a copy of that book for "entertainment purposes".

Guys, guys, guys.... This is about propulsion, not weapons.

A howitzer is simply a single-stroke propulsion engine.

You said it much better than I!

https://www.nasa.gov/press-release/nasa-to-discuss-latest-developments-in-solar-electric-propulsion-for-future-deep-space

That is great for outer space, small payload, or larger systems where the engines are MUX.

I am more interested to see if some sort of plasma gun/fuel gun combo will produce far more thrust (at normal atmospheric pressure up to say 10,000 m altitude).

Why? Glad you asked...perhaps this might be a harbinger of lowering freight costs, reducing road traffic etc. Or maybe usher in a new era of thrill seekers wanting lighter

than air tourism.

Things to rule out: Lithium (although it has the highest specific impulse in plasma engines to date) - cost factor

Anything toxic in the environment we also rule out by default.

Nitrogen, oxygen, carbon dioxide (obtained by recovery from burning tires only) are OK.

The challenge will be to produce the most specific impulse with any prototype engine.

Gentlemen, start your engines (and your engineering). You have only two weeks to the finished product.

First we had Uber, then Google self driving cars, then Uber flying taxicab. Next week we will have plasma engined scootie coots.

Look. Do you want your Jetsons car or not?

Did you write all this yourself?

Please note the quote marks and the referenced link.

Juuuust checkin'.

Interesting summary.

Apparently, it would be easier to use fuel/air combustion waves in a tube.

I certainly agree with your comment, although NASA appears to be working on something like this for VTOL aircraft (most likely drones).

I suspect your "normal" gas turbine style turbo fan jet engine has about the highest specific thrust to weight ratio, and the highest available specific impulse with respect to pounds thrust/fuel lb consumed. The high turn down ratio makes them suitable for most all aspects of flight in ANY aircraft. The oriented duct versions are very interesting, but they might not be as suitable for use with lighter than air craft.

How about if the entire engine pod (which can be large or small??) could be gimbal mounted, even to the point of thrust reversal when docking?

Or simply use a high efficiency gas turbine (maybe even closed Brayton cycle) to power the entire craft, capture the CO2 and water (to whatever extent is convenient), use the CO2 for hydrogen lift bag blanketing sheath gas, use the water as cycle coolant, and the vapor for lift outside the lift bags but inside the envelope? The vapor would condense on selected portions of the skin, and cascade back to storage as coolant, or storage as selective ballast.

The lift bags need to be variable volume, withdrawing hydrogen or adding from time to time to assist with buoyancy against load, lift compensation, balancing for attitude control, etc. A redundant compressor system for the hydrogen. Obviously hydrogen purity monitoring is non-optional in any situation.

Maybe you could make a lighter than air , uh aircraft, that transformed into a more aerodynamic shape as it gains speed...

That is interesting! I know a buddy that might get sidetracked off our LENR experiments for this.

Suppose we use "muscle" polymer, and make the thing expand out blimpy style for take-off and landing, and compress to a lean profile for higher speed.