9 General Categories of Rocket Propellant

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Bruce

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If there are 3 states of matter (not counting plasma) and 2 components to rocket propellant, then doesn't that mean that there could be 3 squared or 9 general categories of rocket propellant?

Fuel-----Oxidizer----Common Name
____________________________________________
Gas-----Gas
Gas-----Liquid
Gas-----Solid
Liquid--Gas
Liquid--Liquid------Liquid Propellant
Liquid--Solid
Solid---Gas
Solid---Liquid-------Hybrid Propellant
Solid---Solid--------Solid Propellant

So, other than the 3 obvious ones, have any of the other 6 been tried?
 
That makes sense about using gasses. Probably anything that a gas could do, a liquid (under high pressure) could do better.

So that leaves only Liquid Fuel with Solid Oxidizer. I'd like to read more about this type of motor. Does anyone have any links?
 
It's sometimes called a reverse hybrid. They tend to be pretty bad overall. Some common combinations include jet fuel and typical solid prop oxidizers. The solid elements tend to be overly brittle, combustion efficiency is poor, ISP is lower, O/F ratios poor and overall it's usually just a bad idea. Gas-solid blends are still hybrids, gas-liquids are considered liquid rocket engines. As far as I know, all of these combinations have been tried with the possible exception of gaseous fuel and solid oxidizer.
 
I'm trying to visualize how a "Reverse Hybrid" might work. Is there a big chunk of solid oxidizer in the case and liquid jet fuel is pumped in?

Or perhaps could you do it more like a liquid-liquid motor and have the solid oxidizer in pellet form and somehow bring the pellets one at a time into the combustion chamber without affecting the chamber's pressure? Something like a revolving door?
 
There are monopropellant gas ion thrusters:

https://en.wikipedia.org/wiki/Ion_thruster
And there are several liquid monopropellants such as Hydrazine and Hydrogen Peroxide. So using your chart they would just be:

Gas------Ionized Monopropellant
Liquid---catalyzed Monopropellant


Tony
 
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It's the first one. The second one tends to be too much hassle and mass to be worth the bother.
 
From the Hybrid History portion of the AeroTech 54mm Hybrid Instruction Manual:

"March, 1992: Under the direction of Gilbert Moore, the Utah section of the AIAA creates a consortium of four northern Utah universities to provide students with education and experience in hybrid rocket propulsion. Unity IV, their first hybrid project, uses GOX and HTPB. The rocket crashes shortly after liftoff due to a leak caused by ignition of combustible grease in a pressure gauge receptacle and the subsequent ejection of the gauge."

http://www.aerotech-rocketry.com/cu...tructions/RMS-Hybrid/54mm_hyb_in_man_6-98.pdf
 
Wouldn't it be fun if we could use double-base propellants?

I'm not sure that using double base propellants would be of any advantage.

It looks like the concept was explored up through at least WW2. One example would be the Tiny Tim air to ship missile,

https://wiki.warthunder.com/Tiny_Tim

It used a double base propellant, Balistite,

https://en.wikipedia.org/wiki/Ballistite

which was developed by Alfred Nobel in the late 19th century.

The propellant was of the high thrust / short duration type and my understanding (correct me if I'm wrong) was that these types of propellant being powder based were limited by how tightly they could be compressed. Even the most highly compressed powder based propellants still had some voids surrounding the particles which had the undesirable property of increasing the burning surface area.

The breakthrough was castable propellant which was invented by Jack Parsons. He introduced asphalt as a binder. This allowed solid propellant to be produced with a minimum of voids. The binder also acted as the fuel, so only an oxidizer needed to be mixed with it simplifying everything. Asphalt was later replaced by the rubber-like compounds used in most solid fuels today.

I've only found the above info by web surfing and am certainly no academic historian. Any corrections would be gladly accepted!
 
There are TWO more types of "propellant" . . .

( 1 ) Tri-Brid - Essentially a motor that operates as a traditional Hybrid ( Liquid Oxidizer / Solid Fuel ) BUT with a Secondary Liquid Fuel ( Alcohol, for example ), injected under pressure, during combustion. "Back in the day", there was AT LEAST one manufacturer ( RATTworks ) that did this.

http://www.rattworks.net/research_tribrid.html

http://www.privatedata.com/byb/rocketry/exp/hybrid/ratt_tribrid/index.html


( 2 ) Monopropellant - 100% Hydrogen Peroxide, for example.

Dave F.
 
The Nike motors use a double base propellant. Useful to the military as they don't leave an obvious target of the launcher.
 
There are TWO more types of "propellant" . . .

( 1 ) Tri-Brid - Essentially a motor that operates as a traditional Hybrid ( Liquid Oxidizer / Solid Fuel ) BUT with a Secondary Liquid Fuel ( Alcohol, for example ), injected under pressure, during combustion. "Back in the day", there was AT LEAST one manufacturer ( RATTworks ) that did this.

http://www.rattworks.net/research_tribrid.html

http://www.privatedata.com/byb/rocketry/exp/hybrid/ratt_tribrid/index.html


( 2 ) Monopropellant - 100% Hydrogen Peroxide, for example.

Dave F.


If we're going to include those, we'll have to add Steam as well!

Maybe it is a monopropellant, but Steam was used for nearly all of the private manned rocket flights - Evel Knieval, Mike Hughes and Eddie Braun. Johnny Knoxville being the sole private manned rocket pilot to use the more conventional solid propellant...
 
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