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A propellant is a material that is used to move ("propel") an object. This will often involve a chemical reaction. It may be a gas, liquid, plasma, or, before the chemical reaction, a solid. This page is about the physical properties of gas as a state of matter Liquid is one of the principal States of matter. A liquid is a Fluid that has the particles loose and can freely form a distinct surface at the boundaries of In Physics and Chemistry, plasma is an Ionized Gas, in which a certain proportion of Electrons are free rather than being bound

Common chemical propellants consist of a fuel, like gasoline, jet fuel and rocket fuel, and an oxidizer. Jet fuel is a type of Aviation fuel designed for use in Aircraft powered by gas-turbine engines. Rocket propellant is mass that is stored usually in some form of Propellant tank prior to being used as the propulsive mass that is ejected from a rocket engine in the form An oxidizing agent or oxidising agent (also called an oxidant, oxidizer or oxidiser) can be defined as either a Chemical compound

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Aerosol sprays

In aerosol spray cans, the propellant is simply a pressurized vapour in equilibrium with its liquid. Aerosol spray is a type of dispensing system which creates an aerosol mist of liquid particles As some gas escapes to expel the payload, more liquid evaporates, maintaining an even pressure. (See aerosol spray propellant for more information. Aerosol spray is a type of dispensing system which creates an aerosol mist of liquid particles )

Solid propellant rockets and projectiles

In ballistics and pyrotechnics, a propellant is a generic name for chemicals used for propelling projectiles from guns and other firearms. Ballistics ( gr βάλλειν ('ba'llein' "throw" is the science of Mechanics that deals with the motion behavior and effects of Projectiles The term "pyrotechnics" can also be used for Fireworks events Some explosive substances can be used both as propellants and as bursters, as for example gunpowder, and some of the ingredients of a propellant may be similar, though differently proportioned and combined, to those of an explosive. Propellants are nearly always chemically different from explosives as used in shells and mines to produce a blasting effect.

A very typical propellant burns rapidly but controllably and non explosively, to produce thrust by gas pressure and thus accelerates a projectile or rocket. Thrust is a reaction force described quantitatively by Newton 's Second and Third Laws. This page is about the physical properties of gas as a state of matter Pressure (symbol 'p' is the force per unit Area applied to an object in a direction perpendicular to the surface A projectile is any object propelled through space by the exertion of a force which ceases after launch A rocket or rocket vehicle is a Missile, Aircraft or other Vehicle which obtains Thrust by the reaction of the In this sense, common or well known propellants include, for firearms, artillery and solid propellant rockets:

Propellants that explode in operation are of little practical use currently, although there have been experiments with Pulse Detonation Engines. A pulse-detonation engine, or "PDE" is a type of propulsion system that can operate from subsonic up to Hypersonic speeds

Liquid propellant rockets

Technically, the word propellants is used for the chemicals combined in a rocket engine to make it move by reactive force. However, amongst the English-speaking lay public, used to having fuels propel vehicles on Earth, the word fuel is inappropriately used. In Germany, the word Treibstoff—literally "drive-stuff"—is used; in France, the word ergols is used; it has the same Greek roots as hypergolic, a term used in English for propellants which combine spontaneously and do not have to be set ablaze by auxiliary ignition system. A hypergolic propellant is either of the two Rocket propellants used in a hypergolic Rocket engine, which spontaneously ignite when they come into contact

Most common are bipropellant combinations, which use two chemicals, a fuel and an oxidiser. There is the possibility of a tripropellant combination, which takes advantage of the ability of substances with smaller atoms to attain a greater exhaust velocity, and hence propulsive efficiency, at a given temperature. Although not used in practice, the most developed theory involves adding a third propellant tank containing liquid hydrogen to do this. In practice, a hydrogen-oxygen engine can take advantage of this by simply adding more hydrogen than would obtain at the stoichiometric ratio. Stoichiometry (sometimes called reaction stoichiometry to distinguish it from composition stoichiometry is the Calculation of Quantitative (measurable

Common propellant combinations used for liquid propellant rockets include:

Sources and references

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See also

Fuel is any material that is burned or altered in order to obtain energy Spacecraft propulsion is any method used to change the velocity of Spacecraft and artificial Satellites There are many different methods Specific impulse (usually abbreviated I sp is a way to describe the efficiency of rocket and jet engines

Dictionary

propellant

-noun

  1. anything that propels
  2. fuel, oxidizer, reaction mass or mixture for one or more engines (especially internal combustion engines or jet engines) that is carried within a vehicle prior to use
  3. the compressed gas in a pressurised container (especially an aerosol can) that is used to expel a liquid

-adjective

  1. Alternative spelling of propellent.
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