Rocket fuel, that is, the fuel for rocket thrusters, includesCO,H2,C2H2,CH4,C2H4,CHthreeCHtwoOH,N2H4, advanced boronsilane(These areRocket thrusterFuel).andFirecrackerOfignitionThe principle is the same, except that the upper layer is not gunpowder, but rocket head (inside is satellite, escape capsule, detector, etc.).The commonly used rocket fuel for launching satellites (spaceships) should be small in size and light in weight, but the heat emitted should be large, so as to reduce the weight of the rocket and enable the satellite (spaceship) to be put into orbit quickly.The energy released by liquid (solid) fuel is large, and the thrust generated is also large;Moreover, this kind of fuel is easy to control and has a long combustion time.Therefore, most rockets that launch satellites (spaceships) use liquid (solid) fuel.[1]
Aviation keroseneIt is colorless and transparent. It smells ordinarykeroseneIt makes no difference and is not volatile.The ignition point is about 3000 ℃, let aloneFlintYes, even with an open fire, it can't be lit.
Carrier rocketWhat power is used to send the spacecraft into space?Long before the invention of carrier rocket, people used oil and steam as fuel, and cars, ships and planes relied on these fuels to run.Later, scientists invented a carrier rocket that uses chemical energy to generate power.The launch vehicle uses kerosene, alcoholUnsymmetrical dimethylhydrazine、Liquid hydrogenAs combustion agentLiquid oxygen、Nitrogen tetroxideThe oxidant provided by, for example, helps to burn. It is used to call the combustion agent and oxidantrocket engineFuel orpropellant。
In terms of physical form,rocket engineThere are two forms of propellant used, one is liquid material, the other is solid material.
Liquid rocket fuel
From the theoretical calculation, the best liquid fuel is liquid hydrogen, which can produce a specific impulse (specific impulse: the ratio of the thrust (kgf) of the rocket engine to the mass flow per second (kg/s) of the ejected particles) of about 350 when mixed with liquid oxygen.If liquid oxygen is replaced by liquid ozone or liquid fluorine, the specific impulse can be increased to about 370.Engines with liquid combustion agents and oxidizers are called liquid fuel engines.In addition to liquid hydrogen, methanol, ethanol, high concentration hydrazine hydrate, dimethylhydrazine, nitro, methane and other substances can be used as liquid rocket fuel.[1]
Solid rocket fuel
Sodium borohydride, dimeric acid diisocyanate, ferrocene and its derivatives can be used as composite solid rocket fuel.Some metals or nonmetals with low density, such as lithium, beryllium, magnesium, aluminum, boron, etc., especially beryllium can release huge energy in the combustion process. The heat released by complete combustion of every kilogram of beryllium is up to 15000 kJ, which is a high-quality rocket fuel, and the heat released is more than hydrogen.These metals are usually made into fuel agents with nanometer sized particles.For example, if nano aluminum or nickel particles with mass fraction of 1 are added to the rocket launched solid fuel propellant, the combustion heat per gram of fuel can be increased by 1 times.However, the disadvantage of these fuels is that some of them are rare and involve technical difficulties in combustion - smoke, oxide deposition, etc.[1]
If one of the two fuels is solid and the other is liquid, it is called solid-liquid rocket engine or rocket engine whose substance is directly named.For example, hydrogen oxygen rocket engine.Since the energy generated by solid combustion agent is higher than that generated by liquid oxidizer, most of the rocket engines developed are solid liquid rocket engines. The two fuels burn together to form high-temperature and high-pressure gas, which is ejected from the nozzle to generate huge thrust and send the carrier rocket into space.
On March 30, 2022 local time, Yonhap News Agency reported that the research institute under the Ministry of Defense of the Republic of Korea successfully test fired a self-developed solid fuel for the first timeFuel rocket.[2]
