What is Propellant: Definition and 25 Discussions

A propellant or propellent is a chemical substance used in the production of energy or pressurized gas that is subsequently used to create movement of a fluid or to generate propulsion of a vehicle, projectile, or other object. Common propellants are energetic materials and consist of a fuel like gasoline, jet fuel, rocket fuel, and an oxidizer. Propellants are burned or otherwise decomposed to produce the propellant gas. Other propellants are simply liquids that can readily be vaporized.
In rockets and aircraft, propellants are used to produce a gas that can be directed through a nozzle, thereby producing thrust. In rockets, rocket propellant produces an exhaust, and the exhausted material is usually expelled under pressure through a nozzle. The pressure may be from a compressed gas, or a gas produced by a chemical reaction. The exhaust material may be a gas, liquid, plasma, or, before the chemical reaction, a solid, liquid, or gel. In aircraft, the propellant is usually a fuel and is combusted with the air.
In firearm ballistics, propellants fill the interior of an ammunition cartridge or the chamber of a gun or cannon, leading to the expulsion of a bullet or shell (gunpowder, smokeless powder, and large gun propellants). Explosive material can be placed in a sealed tube and act as a deflagrant low explosive charge in mining and demolition, to produce a low velocity heave effect (gas pressure blasting).
Cold gas propellants may be used to fill an expansible bag or membrane, such as an automotive airbag (gas generator propellants) or in pressurised dispensing systems, such as aerosol sprays, to force a material through a nozzle. Examples of can propellants include nitrous oxide that is dissolved in canned whipped cream, and the dimethyl ether or low-boiling alkane used in hair spray.
Rocket propellant may be expelled through an expansion nozzle as a cold gas, that is, without energetic mixing and combustion, to provide small changes in velocity to spacecraft by the use of cold gas thrusters.

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  1. J

    A Why the James Webb Space Telescope needs propellant

    Orbits around the Lagrange point are not stable, and you need to tweak your trajectory every now and then to remain in that orbit. Simulations of a non-accelerated body give spectacularly weird results: When the propellant runs out, is this what the JWST will do?
  2. A

    Motion of a rocket with propellant exhaust gas speed = constant

    Now this is how I've tried to solve this $$ v_e = u0 \cdot ln \frac {M} {M- μ \cdot t} $$ After putting in the values I get this; $$ v_e = 200 * ln 0,36 $$ $$ v_e = 73,54 \frac m s $$ Now I'd say that this is the correct way to do it, but this part is confusing me "What is the speed of the...
  3. B

    Best Raw Propellant Sources For A Scifi Spaceship

    Rocketry is not good enough for the standard scifi spaceship that can take off and land like it pleases with high payloads. Yet I still like rocketry because I like the fiery exhaust plumes. So I am considering linking the spaceship's rocket engine to a portal linked to to a planetary...
  4. C

    Is Specific impulse indicative of performance as a gun propellant?

    Black powder has specific impulse of around 80s, while rocket candy has up to 130s of specific impulse. Does that mean I could replace the propellant in a BP cartridge with 80/130 of the weight in rocket candy and obtain the same performance in an idealized gun? (as in without considering...
  5. G

    I Is it possible to propel a spray can with gunpowder?

    Is it possible to pressurize a spray can with gunpowder or something similar, in order to make a reliable spray can with high pressure? I’m asking this question because a small amount of gunpowder generates a huge amount of propelling gasses when ignited. I need to make a compact spray can...
  6. chemisthypnos

    Why are triple base propellants not used in firearms?

    I would think that the use of triple base propellants in hand-held weapons, such as assault rifles or pistols, would be greatly beneficial as its use would remove the muzzle flash. Also, it would decrease wear-and-tear on the weapon itself, I would think. I have found some people saying that...
  7. D

    Intr rocket science: How calculate mass ratio and propellant

    Homework Statement [/B] I was wondering if you'd be able to help me with this problem: Given a two-stage launch vehicle with an engine that produces an Isp =400 sec, a payload mass of 10.000 kg, stage 1 structure mass of 10.000 kg, stage 2 structure mass of 10.000 kg, determine the mass ratio...
  8. V

    Propellant Chemistry Principles

    Time and again one comes across various authors using the sentence "" by the principles of propellant chemistry"", in order to determine the ratios of the complexant (fuel, like glycene, citric acid etc) and the metal salt, in preparatioin of ferrites by sol gel technology. Say for example in...
  9. P

    I need some kind of propellant gas for an experiment

    For the past year or so, I've been experimenting with Isobutane. I used to get it in relatively cheap canisters of r600a from amazon.com and AliExpress, and that worked fine. Now, however, AliExpress has NO purchase options for r600a, and amazon.com will not ship it to the US, even though they...
  10. S

    Photon Rocket vs Conventional Propellant Rocket

    I want to ask about the differences between a photon rocket and a rocket which uses conventional propellant. A conventional rocket shoots exhaust matter out the back end, resulting in impulse and acceleration. A photon rocket shoots photons out the back end, resulting in impulse and...
  11. BilboBombadillo

    Need help finding required Propellant Fraction for equation

    Homework Statement Consider a cryogenic chemical propulsion system with Isp (specific impulse) = 450 s Enter the required propellant fraction as a proportion with at least two decimal places. The ΔVelocity is provided. ΔV = 9.6 km/s Homework Equations Rocket equation: ΔV = Vex x Ln (initial...
  12. P

    Polymer/Propellant Solution

    Ok, I am really close to this. d-Limonene dissolves Polystyrene (I have tested this) and Liquid Isobutane mixes with d-Limonene (I have also tested this) However, when I mix all three together, the Polystyrene becomes completely separated from the solution. Same thing with all polymer solutions...
  13. D

    Is Interstellar Travel Possible with Current Propulsion Technology?

    Let's say a ship is beyond Earth's meaningful gravity pull, and has solar panels. Assume that it can collect solar power and use it in a system which blasts propellant away from the ship to accelerate through space. The ship's goal is to leave the solar system and reach a new star, but to...
  14. Vorde

    What is Propellant Utilization? | Learn About Rocket Launches

    This is a ridiculously easy question, so I apologize for bugging you all with it, but google has been less than helpful. Consistently when I watch videos of rocket launches I hear operators talking about propellant utilization being active (usually with individual stages singled out). What does...
  15. C

    Best propellant for space shuttle?

    The Swedish SMART-1 used a Hall effect thruster which used Xenon gas. Xenon costs 1200 USD per Kg. Why didn't they use Helium instead which costs 50 USD per Kg? New Horizons probe launch in 2006 used a Radioisotope Thermoelectric Generator which used Americium-241. Americium cost 1,5 million...
  16. Filip Larsen

    Live! Witness TM65 Liquid Propellant Rocket Engine Testing

    A livestream video feed from the event has started and can be accessed via the CS homepage [1] or the corresponding blog on Wired [2]. Some background information about CS can be found on [3] together with a (very) short description on the TM65 [4]. [1] http://www.copenhagensuborbitals.com/ [2]...
  17. D

    Nuclear pulse propulsion with low Z propellant?

    I've been doing some reading about Orion-drive spacecraft , but I don't understand the requirement of a high Z propellant like tungsten. Assuming that the pulse unit were detonated further away from the craft to prevent it from drilling a hole in the pusher plate due to its narrower angle, why...
  18. S

    Hydrogen Propellant: Can it Power an Engine?

    Can hydrogen be burned and used to drive an engine?
  19. C

    Acceleration, thrust, and propellant velocity?

    Homework Statement What is the average acceleration until burnout of a spacecraft engine creating 53.2MN of thrust with a propellant velocity of 4.78km/s? The initial mass is 2.12x10^6 kg and final ,*** is 7.04x10^4. Homework Equations 0 = m(subscript_f)v(_f) + m(_r)v(_r) The...
  20. E

    KNO3 Sugar rocket propellant and safety

    Hi, I am new to building large candy rockets, and I have a target of building a candy rocket that can reach an altitude of over 40,000ft. I am mostly concerned with the safety when casting such propellants. I am looking at casting over 200 pounds of propellant. Any one got any advice. I have...
  21. T

    What percentage of the gas propellant in the completely filled propuls

    Homework Statement An astronaut in his space suit and with a propulsion unit (empty of its gas propellant) strapped to his back has a mass of 143 kg. During a space-walk, the unit, which has been filled with propellant gas, ejects some gas with a velocity of +30.9 m/s. As a result, the...
  22. G

    Solid Propellant Burn Rate Sensitivity

    I have been flying some model rockets powered by commercially available solid propellant engines. I have been flying at an elevation of 2550 above sea level. I am headed to a competition next week and will be flying near sea level. The air density will change approximately 5% due to the...
  23. W

    Smart 1 Ion Drive Propellant

    Has arrived, eventually. http://www.sci.esa.int/science-e/www/area/index.cfm?fareaid=10 [Broken] propulsion details here:http://www.sci.esa.int/science-e/www/object/index.cfm?fobjectid=34201 [Broken]
  24. C

    Bringing Propellant To Space

    Eventually, if we want to establish outposts in our solar system, starting with the Moon, we will need a continuous source of propellants. A space station in LEO and in lunar orbit would be needed. Let's say the propellant of choice is hydrogen and oxygen. What would be the best way of getting...
  25. frankR

    Cannon physics: detailed inquiry of projectile propellant.

    I was bored earlier today, so I concluded the best way to elevate my boredom was to exercise my brain for next quarter. The best way to exercise your brain is to do a little physics, right? I started to think of a problem. I came up with a classic projectile problem: A cannon fires a...