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Plasma Thrusters Enhanced with Chemical Rockets


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Out of curiosity, why not make a chemical rocket that takes a neutrally charged atom and ionizes it (normal plasma thrust based off of this (https://en.m.wikipedia.org/wiki/Ionization_energy) take that negatively charged ion and confine it to a few atoms thick of a stream via magnets (pretty much the inverse of the magnetic nozzle mentioned in the below thread)  and then inject a positively charged fuel for a super heated chemical reaction in addition to the plasma thrust? You could even use the fuel to (ever so slightly) cool down the systems while the rocket is operating to prevent suddenly unplanned disassemblies.

 

basically inverse that nozzle right here

https://images.search.yahoo.com/images/view;_ylt=AwrJ7JYjS1Ndo94ASgDBGOd_;_ylu=X3oDMTByMjB0aG5zBGNvbG8DYmYxBHBvcwMxBHZ0aWQDBHNlYwNzYw--?p=vasmir&back=https%3A%2F%2Fsearch.yahoo.com%2Fsearch%3Fp%3Dvasmir%26ei%3DUTF-8&no=1&fr=ipad&h=538&w=800&imgurl=www.adastrarocket.com%2Fimages%2Fvasimr.jpg&rurl=http%3A%2F%2Fwww.adastrarocket.com%2Faarc%2FVASIMR&size=167KB&name=Our+Engine+|+Ad+Astra+Rocket&oid=OIP.GsYVg3OCb0XTl3otHHh1gQHaE-&tt=Our+Engine+|+Ad+Astra+Rocket&sigr=118flh152&sigi=1176d8m4i&sigb=11hraf1qq&sign=10skd8o6n&sigt=10skd8o6n

Use the magnet to get the plasma into a small beam accelerating it due to the pressure even more. Then inject the positive ions, let’s call it LOX for now. (let’s suppose you ionize hydrogen or helium) Then expand the nozzle into a combo between a chemical and magnetic nozzle. Perhaps double layered, one to take the brunt of the heat (perhaps ablative due to the high heat) and then the magnetic one to keep non-reacted ions from reacting with the ablative rocket nozzle.

 

I should clarify that I know temperature’s will get very high and that is a problem, I also do not know a ton about plasma engines, I was just looking into them a bit. I was reading this page ( https://en.m.wikipedia.org/wiki/Plasma_propulsion_engine ) and thought that perhaps if you reduced the amount of required ions you may be able to reduce the electricity needed and thus with the chemical addition be able to get a better TWR

 

Inspired by this thread

 

 

 

Edited by Cheif Operations Director
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This is similar to something I have wondered about for some time. Why can't you boost a rocket engine with a magnetic field? Turns out rocket exhaust isn't that ionized. But, how could you increase that? would there be a benefit? What if you already had the power to run the field in your payload? I am nearly completely out of my element answering any of those questions.

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15 minutes ago, AngrybobH said:

This is similar to something I have wondered about for some time. Why can't you boost a rocket engine with a magnetic field? Turns out rocket exhaust isn't that ionized. But, how could you increase that? would there be a benefit? What if you already had the power to run the field in your payload? I am nearly completely out of my element answering any of those questions.

Yea but if we intentionally ionized the air we could make hypergonic fuel in flight with hydrogen and oxygen and get a ton of heat and pressure to accelerate a small amount of propellant (in theory, theory in the non scientific sense)

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2 hours ago, Cheif Operations Director said:
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screenshot.png

Something like this (excuse the bad sketch) the purple is your run of the mill plasma thruster, the it pushes the ionized fuel (purple) into the combustion chamber where a small amount of LOX is added for combustion.

I believe the LOX would just get immediately ionized and just join the outward flow of reaction mass, only being able to chemically combine with your fuel long after it has left the nozzle.

The only net effect I can forsee is a lower ISP due to a higher molecular mass of the exhaust.

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1 minute ago, Nothalogh said:

I believe the LOX would just get immediately ionized and just join the outward flow of reaction mass, only being able to chemically combine with your fuel long after it has left the nozzle.

The only net effect I can forsee is a lower ISP due to a higher molecular mass of the exhaust.

why would it get immediately ionized?

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Just now, Cheif Operations Director said:

why would it get immediately ionized?

Because the local environmental conditions of PLASMA tend to preclude chemical bonds forming at all.

Just now, kerbiloid said:

If you have some much power to accelerate, why complicate the engine with chemistry? Just ionize it.

Where else will the toilet flush to?

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1 minute ago, kerbiloid said:

If you have some much power to accelerate, why complicate the engine with chemistry? Just ionize it by heating.

To get a high thrust?

1 minute ago, Nothalogh said:

PLASMA tend to preclude chemical bonds forming at all.

what if you put it right at the line so some of it was plasma and some of it was not?

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5 minutes ago, Nothalogh said:

Where else will the toilet flush to?

In a small ship toilet is to be flushed into kitchen, they are just two sides of a coin. Just recycle in between.

3 minutes ago, Cheif Operations Director said:

To get a high thrust?

You can ionize elements  of any atomic number and mass.

Edited by kerbiloid
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1 minute ago, Cheif Operations Director said:

Yes but most of the advantages would still be their right? I mean the super hot gases and plasma accelerating the explosive material out even faster of the nozzle creating more pressure?

Well any chemical reaction would have to occur after the plasma had condensed back to gas, which would be outside of your engine bell

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Just now, Nothalogh said:

Well any chemical reaction would have to occur after the plasma had condensed back to gas, which would be outside of your engine bell

So Plasma's are always incapable of bonding even with other plasma's?

 

1 minute ago, kerbiloid said:

So, ionize a piece of iron when you need high atomic mass.

wait what? Im not following you sorry

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Just now, Cheif Operations Director said:

So Plasma's are always incapable of bonding even with other plasma's?

 

In the state of plasma, the electrons are otherwise indisposed, electrons do the bonding.

If there is bonding going on in your plasma, you have FUSION, and that means your containment and cooling system is about to have a problem

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1 minute ago, Nothalogh said:

In the state of plasma, the electrons are otherwise indisposed, electrons do the bonding.

If there is bonding going on in your plasma, you have FUSION, and that means your containment and cooling system is about to have a problem

Alright, I need to sleep I will continue tomorrow sorry

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8 minutes ago, Cheif Operations Director said:

Yes but most of the advantages would still be their right? I mean the super hot gases and plasma accelerating the explosive material out even faster of the nozzle creating more pressure?

Problem is that you need an power source. think the afterburner will be pretty heavy and have an minimum power demand who is also pretty high. 

Why not just stage and use an ion engine or other engines who is high isp but low trust. 

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It is a dilemma as old as rocketry.

Usually you want your engine as efficient as possible. Thus, Isp is king.

But... you also want your engine powerful enough to move your craft at reasonable pace. For that you need good thrust.

Current engines we can built, can have one. Electric engines give high fuel efficiency, chemical rockets give high power.

How can we combine the two? Ideas range from:

Literally combine two separate engine sets on one rocket. Chemical engines for high energy maneuvers, electric engine for interplanetary cruise...

To crazy sci-fi ideas like Saltwater rocket or Orion.

 In-between lie more sensible projects like NERVA, VASIMR, MagnetoPlasmaDynamic thrusters or Fusion Pulse engines.

But hybridising ion and chemical engine? It looks kind of 'Meh' to me. It will significantly increase the mass by adding chemical fuel (with necessary tankage and plumbing), while crippling the biggest advantage of the electric engine (high Isp!), without increasing thrust appreciably.

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5 hours ago, Scotius said:

But hybridising ion and chemical engine? It looks kind of 'Meh' to me. It will significantly increase the mass by adding chemical fuel (with necessary tankage and plumbing), while crippling the biggest advantage of the electric engine (high Isp!), without increasing thrust appreciably.

what part of this design causes the high Isp. I want to make sure we are on the same page here

28 minutes ago, DDE said:

@Cheif Operations Director, I think you’re looking for augmented thrusters. The transfer of additional energy is through mundane resistojet or arcjet systems, and they also replace the usual catalyst bed in a hydrazine thruster.

Yes I think it may be the same idea. A sort of combo between the two

6 hours ago, magnemoe said:

afterburner will be pretty heavy and have an minimum power demand who is also pretty high. 

I would be your run of the mill chemical rocket

 

6 hours ago, magnemoe said:

Problem is that you need an power source.

Nulcear reactor perhaps?

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2 hours ago, Cheif Operations Director said:

what part of this design causes the high Isp

The atomic mass of whatever you are shoveling into the it, turning into plasma, and then magnetically accelerating out the rear.

The lower the mass, the higher the ISP.

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Just now, Nothalogh said:

The atomic mass of whatever you are shoveling into the it, turning into plasma, and then magnetically accelerating out the rear.

The lower the mass, the higher the ISP.

Ok, that is what I thought so how would I be costing a large decrease in ISP if I am expelling a mostly small amount of fuel out of the back? Remember I need 2 H and 1 O for H20 so If we suppose I am expelling 1,000,000 hyrodgen atoms a second I need 500,000 oxygens. I am getting that acceleration from the base plasma thruster, I am then combining the already very fast particles in gaseous form. It transitions from a plasma to a gas in the combustion chamber.and then creates even more pressure, not less. 

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