Cryogenic fuel
Encyclopedia
Cryogenic fuels are fuel
s that require storage at extremely low temperatures in order to maintain them in a liquid state. Cryogenic fuels most often constitute liquefied
gas
es such as liquid hydrogen
.
Some rocket engine
s use regenerative cooling
, that is circulate their cryogenic fuel around their nozzle
s before the fuel is pumped into the combustion chamber
and ignited. This arrangement was first suggested by Eugen Sänger
in the 1940s. The Saturn V
rocket that sent the first manned missions to the moon used this design element, which is still in use today.
Quite often, liquid oxygen
is mistakenly called cryogenic "fuel", though it is actually an oxidizer and not a fuel.
Russian aircraft manufacturer Tupolev
developed a version of its popular Tu-154 design but with a cryogenic fuel system, designated the Tu-155. Using a fuel referred to as liquefied natural gas
(LNG), its first flight was in 1989.
India developed the technology in 2008 for use in their GSLV rockets.
Fuel
Fuel is any material that stores energy that can later be extracted to perform mechanical work in a controlled manner. Most fuels used by humans undergo combustion, a redox reaction in which a combustible substance releases energy after it ignites and reacts with the oxygen in the air...
s that require storage at extremely low temperatures in order to maintain them in a liquid state. Cryogenic fuels most often constitute liquefied
Liquification
In physics, to liquefy means to turn something into the liquid state.-In Geology:In geology, liquefaction refers to the process by which saturated, unconsolidated sediments are transformed into a substance that acts like a liquid.Earthquakes can cause soil liquefaction where loosely packed,...
gas
Gas
Gas is one of the three classical states of matter . Near absolute zero, a substance exists as a solid. As heat is added to this substance it melts into a liquid at its melting point , boils into a gas at its boiling point, and if heated high enough would enter a plasma state in which the electrons...
es such as liquid hydrogen
Liquid hydrogen
Liquid hydrogen is the liquid state of the element hydrogen. Hydrogen is found naturally in the molecular H2 form.To exist as a liquid, H2 must be pressurized above and cooled below hydrogen's Critical point. However, for hydrogen to be in a full liquid state without boiling off, it needs to be...
.
Some rocket engine
Rocket engine
A rocket engine, or simply "rocket", is a jet engineRocket Propulsion Elements; 7th edition- chapter 1 that uses only propellant mass for forming its high speed propulsive jet. Rocket engines are reaction engines and obtain thrust in accordance with Newton's third law...
s use regenerative cooling
Regenerative cooling
Regenerative cooling in rockets is where some or all of the propellant is passed through tubes, channels or otherwise in a jacket around the combustion chamber or nozzle to cool the engine because the fuel in particular and sometimes the oxidizer are good coolants...
, that is circulate their cryogenic fuel around their nozzle
Nozzle
A nozzle is a device designed to control the direction or characteristics of a fluid flow as it exits an enclosed chamber or pipe via an orifice....
s before the fuel is pumped into the combustion chamber
Combustion chamber
A combustion chamber is the part of an engine in which fuel is burned.-Internal combustion engine:The hot gases produced by the combustion occupy a far greater volume than the original fuel, thus creating an increase in pressure within the limited volume of the chamber...
and ignited. This arrangement was first suggested by Eugen Sänger
Eugen Sänger
Eugen Sänger was an Austrian-German aerospace engineer best known for his contributions to lifting body and ramjet technology.-Early career:...
in the 1940s. The Saturn V
Saturn V
The Saturn V was an American human-rated expendable rocket used by NASA's Apollo and Skylab programs from 1967 until 1973. A multistage liquid-fueled launch vehicle, NASA launched 13 Saturn Vs from the Kennedy Space Center, Florida with no loss of crew or payload...
rocket that sent the first manned missions to the moon used this design element, which is still in use today.
Quite often, liquid oxygen
Liquid oxygen
Liquid oxygen — abbreviated LOx, LOX or Lox in the aerospace, submarine and gas industries — is one of the physical forms of elemental oxygen.-Physical properties:...
is mistakenly called cryogenic "fuel", though it is actually an oxidizer and not a fuel.
Russian aircraft manufacturer Tupolev
Tupolev
Tupolev is a Russian aerospace and defence company, headquartered in Basmanny District, Central Administrative Okrug, Moscow. Known officially as Public Stock Company Tupolev, it is the successor of the Tupolev OKB or Tupolev Design Bureau headed by the Soviet aerospace engineer A.N. Tupolev...
developed a version of its popular Tu-154 design but with a cryogenic fuel system, designated the Tu-155. Using a fuel referred to as liquefied natural gas
Liquefied natural gas
Liquefied natural gas or LNG is natural gas that has been converted temporarily to liquid form for ease of storage or transport....
(LNG), its first flight was in 1989.
India developed the technology in 2008 for use in their GSLV rockets.