Repeller Engine

[Eagle1Division]

Here's a neat idea I came up with, I can't wait to see how it doesn't work
Inspired by the fusion Bussard Ramjet concept...
Here's a blueprint.

A: Positively-charged parabolic structure.
B: Negatively-charged parabolic structure.
C: Positively-charged "tunnel".
D: Slightly negatively charged tunnel.
E: Fusion powerplant.
F: High velocity negatively-charged hydrogen cloud - fired from stationary ground installation.
G: Particles given a velocity component towards the middle of the structure, (B).
H: Structure (B) repels negatively charged particles, acting like an MPD thruster.
I: Plasma is "pulled" by larger grid (A), but is traveling above escape velocity from impulse received at (B).

That's the general idea of how it produces thrust, but how it works is a little more in-depth.
The tunnel at (C) traps some of the hydrogen gas, ultimately it's slowed down tremendously by (B), but the extra velocity granted by this section of "tunnel" allows it to pass the grid at a much slower velocity. This Hydrogen is used for nuclear fuel in the fusion reactor (E), then either disposed of or a small portion could be kept as reaction mass in the RCS system.
The fusion powerplant generates the power to keep the charges separate and strong, as well as powering other systems on-board the ship.

I think the idea is similar to a variation of the Solar Sail that uses solar wind, rather than light to create impulse, except in this case hydrogen fired artificially is used, and unlike other designs (A) condenses the vapor cloud so that the density is much, much higher, allowing (B) to be much smaller, and thus lighter.

Overall, the thrust comes from magnetic pressure. The advantages are that not only is the momentum of the hydrogen gas imparted on the engine, but it's also repelled to a higher or equal velocity, so that it receives roughly twice the impulse, without carrying reaction mass or fuel. I suspect the loss of speed at (I) would make it something along the lines of 1.1-1.4x momentum, though, since (A) would attract to (I).

I'm posting it here not because I think I've discovered some great new drive - but because I'm not sure magnetic charges would work this way. I calculated it using the inverse-square law for force, only to realize that magnetic fields don't work based off the inverse-square law!... Do they? Do attraction and repulsion work inverse-square law? If so, then this system does work.

 

[RisingFury]

Wait... are you shooting negatively charged Hydrogen?!?! Not in this universe! A charged hydrogen is just a proton. Protons are positively charged.


Also, if you're shooting some other negatively charged particles (electrons or such) you'll have several problems... For one, would the negatively charged particles just stick to the positive parabolic dish? Generally to redirect them, you'd need to keep the outer parabolic dish negatively charged. But then after you redirected your particles, they'd stick to the inner structure. To prevent that, you'd need to make holes in the inner parabola, kinda like an ion engine... but then you've only redirected your ion stream 90°. Enough to produce thrust, but not exactly what you expected...

There's also the problem that all of these charged particles create an electric field of their own. That's gonna screw up the field you've set up with your parabolas. For example, ion engines choke if you try to increase the propellant flow rate.

There's also the issue of synchrotron losses, but those can be overcome by a great enough field strength... but that puts you before another uncomfortable situation - any free electrons in the material you're using to construct the dishes would re-arrange in such a way to decrease the field strength or even break loose of the material and fly to the other parabola, if the field was strong enough.


I don't know... I'd rather play around with magnetic fields. Though I must say your design kinda reminds me more of the Pelton turbine then Buzzard ramjet, both in design and theory of operation

 

[Eagle1Division]

Haha! That was fast!
What if the cloud was positively charged? The reason for using negatively charged particles was lower mass, higher velocity, which has a few advantages...
But what if it was a positively charged cloud?

(You see, I really don't know about this sort of stuff, but I really, really wish I did...)

 

[Wishbone]

Am really really sorry, but the best design for repeller engine relies on... drumroll... astronaut/cosmonaut socks, if the resupply ship is overdue...

 

[T.Neo]

That is a very interesting concept... I make out that you are using external reaction mass, but internal energy storage.

I have issues with beamed power, especially here one would worry about dispersion and velocity that needs to be imparted to the beamed propellant.

You should look at magnetic sails- not only can magnetic sails be used in tandem with beamed plasma, but could also use the interstellar medium to slow down a spacecraft from high speeds without propellant...

 

[Eagle1Division]

That is a very interesting concept... I make out that you are using external reaction mass, but internal energy storage.

I have issues with beamed power, especially here one would worry about dispersion and velocity that needs to be imparted to the beamed propellant.

You should look at magnetic sails- not only can magnetic sails be used in tandem with beamed plasma, but could also use the interstellar medium to slow down a spacecraft from high speeds without propellant...

The problem with Sails IMO is that they rely on the sun's radiation, which at those distances is extremely weak, and as for using beamed thrust, I, also have issues with the dispersion, which is exactly why I even thought of this drive, the outer dish (A) pulls in the cloud, so it's far, far more dense than it otherwise would've been.

Also, unlike a solar sail, the inner dish (B) not only stops the particles, but then accelerates them rearwards, adding additional momentum to the engine.

Of course, they wouldn't be a solid structure, more like the net-like grids employed in the Fusion Ramjet concept.

The tower C-D pulls in gas for use in the reactor, but perhaps it would be better to place it somewhere else?... Perhaps as a 3rd, outer parabolic grid?

 

[T.Neo]

'Pulling in' the propellant won't help if it disperses and misses your ship entirely. The problem is similar to that of beamed propulsion using a magnetic sail.

The magnetic sail does not need to use solar plasma- at those distances doing so would probably be pretty ineffective. You use accelerated particles from a... particle... accelerator.

The other option is to (while decelerating) use the tenuous interstellar medium to slow down your spacecraft... by using a magnetic sail. You don't really need a star spewing out plasma for that.

 

[RisingFury]

With a lot of effort you could get the cloud to deflect from the outer dish to the inner one... but there isn't anything there that would deflect the cloud back away from the ship. The field inside the cup of small parabola is almost 0...

 

[Eagle1Division]

With a lot of effort you could get the cloud to deflect from the outer dish to the inner one... but there isn't anything there that would deflect the cloud back away from the ship. The field inside the cup of small parabola is almost 0...

Why is that? The outer and inner parabolas could have any amount of charge, really, but the original idea is that they'd have the same amount of charge, so that overall the vessel would be neutral, and also because that would be the best amount for condensing a beam that's been dispersing over AU's, and possibly even LY's.

Because of Coulomb's inverse-square law, the particle will be influenced far more strongly by the charge of the closer dish, to the square, even if the closer dish has a weaker charge. The idea is that any particles that would normally miss the vessel would be attracted towards the inner dish by the outer dish (which, since the outer dish has a larger diameter, would be closer to any particles that would normally miss.) Once the outer dish accelerates them on a vector into the inner dish, they're "trapped" inside (don't have enough momentum to escape) and accelerated out the back.

The outer dish may be much larger, and even have an equal charge, but they're given enough impulse by the smaller dish that they're travelling well above "escape velocity" for the outer dish, so the net effect is that they still accelerate away, imparting a significant amount of momentum on the engine.

(I keep saying dish, but it would really be more like a very thin wire mesh, that's mostly empty space. After all, particles have to travel through it...)

I originally came up with the idea purely on the assumption that electric charge has a force that works by the inverse-square. To my pleasure, I've recently discovered Coulomb's Law, that it does.

I want to create a mathematical model of this and run a sim of it using some programming, then record each simulated "particle" to see if it creates a net change in velocity, how much so, or if it doesn't work at all.
Would calculating forces given by a multiplier and inverse-square of distance (i.e., using Coulomb's Law) alone be a good way to create a simulation of it, or would I have to account for the structure of a magnetic field, even if the dishes only have an electrostatic charge?