Making Ironman Repulsors

[sevenperforce]

Ironman has to be, hands-down, the coolest character in the MCU, at least as far as technology and engineering is concerned. In particular, the way his suits function and fit together just feel intrinsically real and believable.

And of course, we have real-world 3D-printed titanium suits lightweight enough to walk around in, like the one Adam Savage built:

Not only is it actually bulletproof, but it can actually fly, with the right attachments:

The crazy "arc reactor" power source and the associated repulsors, of course, are what make the suit function in-universe. The in-universe explanation is that the repulsors produce a "muon beam", and we know they require palladium, so it is likely that they are supposed to be a cold fusion reactor which creates a stream of muons which can be "tuned" to decay at a given location, allowing them to dump their energy wherever it is wanted. This way the reaction mass is the surrounding air which is simply supercharged with a decaying muon stream. Of course, cold fusion doesn't exist and palladium-catalyzed cold fusion wouldn't produce muon beams anyway, but that's beside the point.

People have done a lot of DIY adaptations of Ironman's repulsors, including lasers and even oxyhydrogen blasters. But, based on the way they look in the movies, I wonder if they could be replicated more closely with some sort of pulsejet or even pulse detonation engine.

If we take a close look at the way the repulsors are depicted in the first film, a few things pop out:

In the first gif, Tony is assuring Pepper that it's just a flight stabilizer and it's completely harmless. He hits the activation switch, and a few moments later, the repulsor starts to glow and the air in front of it becomes distorted, as if it is producing an invisible beam of heat. A moment later, you can see a flash along his forearm and then the repulsor erupts with a massive pulse of energy and thrust.

That same flash along his forearm is some sort of energy transfer coming from the arc reactor in his chest, as seen in the second gif.

So we have a mechanism of some kind in the hand which builds up energy and then is fed a little bit of whatever is coming out of the arc reactor; once it reaches the mechanism in the hand it produces a concussive/thrust beam. It feels very much like a buildup and combustion/detonation inside of a pulsejet or pulse detonation engine.

The major advantages of a pulse detonation engine are that they can be miniaturized and that the detonation itself provides the necessary compression, obviating the need for a compressor or other fan in an airbreathing engine. This is precisely what a real-world ironman suit would need, given that there is no room for any visible compressor fans (and such fans are extremely heavy). I wonder how difficult it would be, really, to fit something like that into a mechanism like this.

Edited June 27, 2022 by sevenperforce

[Spacescifi]

Nice scifi thread Sevenperforce, did not think you had it in you lol!

 

Anyway you are not going to want hear me say it but I have to.

WASTE HEAT.

I reckon the ironman suit would need to at least be the size and weignt of Iron Monger to either not overheat Tony Stark or provide so much impulse that it breaks his joints on a single pulse.

Still it is a cool idea, but one that I really think should be scaled up for a space plane or first stage rocket or SSTO.

 

 

Edited June 27, 2022 by Spacescifi

[kerbiloid]

They can the same, but also shrink.

Spoiler

Wasp rulez!

[sevenperforce]

6 hours ago, Spacescifi said:

Nice scifi thread Sevenperforce, did not think you had it in you lol!

6 hours ago, Spacescifi said:

Anyway you are not going to want hear me say it but I have to.

WASTE HEAT.

Cold fusion.

A real-world analogue would use primarily electrohydromagnetic systems so it wouldn't be an issue.

6 hours ago, Spacescifi said:

I reckon the ironman suit would need to at least be the size and weignt of Iron Monger to either not overheat Tony Stark or provide so much impulse that it breaks his joints on a single pulse.

None of this makes sense.

6 hours ago, Spacescifi said:

Still it is a cool idea, but one that I really think should be scaled up for a space plane or first stage rocket or SSTO.

High-hertz detonation engines can absolutely be scaled up for an airbreathing spaceplane but that has nothing to do with anything.

[wumpus]

10 hours ago, sevenperforce said:

A real-world analogue would use primarily electrohydromagnetic systems so it wouldn't be an issue.

Unless your efficiency is perfect, there will be vast amounts of waste heat.  Of course, the atmosphere provides an ideal heatsink, but there will always be an issue of which way the heat is vented and whether or not you can be near anyone else (not wearing such a suit) while wearing the suit.  Would be quite sad if you turned and walked away and incinerated your companion in the vented heat (flowing out behind you).  Perhaps you'd have to practice backing away from people before turning around, like a courtier leaving a king.

[sevenperforce]

47 minutes ago, wumpus said:

Of course, the atmosphere provides an ideal heatsink, but there will always be an issue of which way the heat is vented

I think the heat is vented via the repulsors, no?

Like, the atmosphere you’re compressing and igniting is what carries the heat away.

[Terwin]

1 hour ago, sevenperforce said:

I think the heat is vented via the repulsors, no?

Like, the atmosphere you’re compressing and igniting is what carries the heat away.

That is only the heat that is deliberately generated by the repulsors, there is generally also waste heat generated by pushing a current through a wire, friction from moving parts, etc  (like how computer processor chips need a heat-sink because they produce a lot of waste heat)

Unless you are using an open-circuit cooling process, you are probably not ejecting it as part of your thrust pulses.

Also, if you are only heating up the air outside of any sort of containment, how are you keeping that heated air from rushing back over your limbs as it expands?  How are you getting thrust from the expansion of an external bubble of gas unless it pushes against you(and thus conducts the heat to your suit)?

 

[wumpus]

1 hour ago, sevenperforce said:

I think the heat is vented via the repulsors, no?

Like, the atmosphere you’re compressing and igniting is what carries the heat away.

Mostly, but most engines get hot regardless of the exhaust.  I'd expect it to require cooling after you land, and if all that cooling air is directly down it will scatter at the ground and cook the legs of anyone nearby.

[Spacescifi]

 

The arc reactor would have gave Stark burns as would th.e wire

[kerbiloid]

https://screenrant.com/robert-downey-jr-iron-man-eating-mcu-movies-reason/

Maybe this plays a role in the starksuit power balance, too?

[sevenperforce]

On 6/28/2022 at 2:59 PM, wumpus said:

Mostly, but most engines get hot regardless of the exhaust.  I'd expect it to require cooling after you land, and if all that cooling air is directly down it will scatter at the ground and cook the legs of anyone nearby.

If you keep the combustion localized that will be the bulk of the waste heat.

One idea for creating a pulsed detonation engine would be to have numerous small combustion chambers where the detonation in one chamber provides direct thrust but also rotates the turbine which compresses and initiates the next detonation, and so forth all around. Like a weird cross between a reciprocating engine and a turbine engine and a ramjet.