Information about Liquid Hydrogen
Liquid hydrogen is the liquid state of the element hydrogen. It is a common liquid rocket fuel for rocket applications. In the aerospace industry, its name is often abbreviated to LH2 or LH2. Hydrogen is found naturally in the molecular H2 form, thus the H2 part of the name.
To exist as a liquid, H2 must be pressurized and cooled to a very low temperature, 20.27 K (−423.17 °F/−252.87°C).[1] One common method of obtaining liquid hydrogen involves a compressor resembling a jet engine in both appearance and principle. Liquid hydrogen is typically used as a practical form of storing hydrogen. As in any gas, storing it as liquid takes less space than storing it as a gas at normal temperature and pressure. Once liquified it can be maintained as a liquid in pressurized and thermally insulated containers.
Liquified hydrogen can be used as a fuel in an internal combustion engine. Various concept hydrogen vehicles have been built using this form of hydrogen (see BMW H2R).
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To exist as a liquid, H2 must be pressurized and cooled to a very low temperature, 20.27 K (−423.17 °F/−252.87°C).[1] One common method of obtaining liquid hydrogen involves a compressor resembling a jet engine in both appearance and principle. Liquid hydrogen is typically used as a practical form of storing hydrogen. As in any gas, storing it as liquid takes less space than storing it as a gas at normal temperature and pressure. Once liquified it can be maintained as a liquid in pressurized and thermally insulated containers.
Uses
In rocket engines, liquid hydrogen is frequently used as a coolant to cool the engine nozzle (regenerative cooling) and other parts before being mixed with the oxidizer (often liquid oxygen (LOX)) and burned. In such a rocket, even with thermally insulated containers it is impossible to avoid the heating of such a cold liquid, and the hydrogen will gradually evaporate. The resulting exhaust of such LH2 - LOX engines is very clean water with traces of ozone and hydrogen peroxide.Liquified hydrogen can be used as a fuel in an internal combustion engine. Various concept hydrogen vehicles have been built using this form of hydrogen (see BMW H2R).
Drawbacks
In terms of energy density, liquid hydrogen requires much more volume than other fuels to store the same amount of energy. Four litres of liquid hydrogen are needed to match the same energy content of one litre of gasoline. On the other hand it is also one of the lightest fuels available; 1 litre of hydrogen weighs only 0.07 kg. That is a density of 70.8 kg/m³ (at 20 K).References
Liquid is one of the four principal states of matter. A liquid is a fluid that can freely form a distinct surface at the boundaries of its bulk material.
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Characteristics
A liquid's shape is determined by, not confined to, the container it fills...... Click the link for more information.
1, −1
(amphoteric oxide)
Electronegativity 2.20 (Pauling scale) More
Atomic radius 25 pm
Atomic radius (calc.) 53 pm
Covalent radius 37 pm
Van der Waals radius 120 pm
Miscellaneous
Thermal conductivity (300 K) 180.
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(amphoteric oxide)
Electronegativity 2.20 (Pauling scale) More
Atomic radius 25 pm
Atomic radius (calc.) 53 pm
Covalent radius 37 pm
Van der Waals radius 120 pm
Miscellaneous
Thermal conductivity (300 K) 180.
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Liquid fuels are those combustible or energy-generating molecules that can be harnessed to create mechanical energy, usually producing kinetic energy; they also must take the shape of their container.
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Rocket propellants undergo exothermic chemical reactions which produce hot gas which is used by a rocket for propulsive purposes.
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Overview
Rockets create thrust by expeling mass backwards in a high speed jet (see Newton's Third Law )...... Click the link for more information.
Spacecraft propulsion is any method used to change the velocity of spacecraft and artificial satellites. There are many different methods. Each method has drawbacks and advantages, and spacecraft propulsion is an active area of research.
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Please help [ improve this article] by expanding this section.
See talk page for details. Please remove this message once the section has been expanded. (tagged since March 2007)
See talk page for details. Please remove this message once the section has been expanded. (tagged since March 2007)
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1, −1
(amphoteric oxide)
Electronegativity 2.20 (Pauling scale) More
Atomic radius 25 pm
Atomic radius (calc.) 53 pm
Covalent radius 37 pm
Van der Waals radius 120 pm
Miscellaneous
Thermal conductivity (300 K) 180.
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(amphoteric oxide)
Electronegativity 2.20 (Pauling scale) More
Atomic radius 25 pm
Atomic radius (calc.) 53 pm
Covalent radius 37 pm
Van der Waals radius 120 pm
Miscellaneous
Thermal conductivity (300 K) 180.
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molecule is defined as a sufficiently stable electrically neutral group of at least two atoms in a definite arrangement held together by strong chemical bonds.[1][2] In organic chemistry and biochemistry, the term molecule
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rocket engine is a reaction engine that takes all its reaction mass from within tankage and forms it into a high speed jet, thereby obtaining thrust in accordance with Newton's third law.
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A coolant, or heat transfer fluid, is a fluid which flows through a device in order to prevent its overheating, transferring the heat produced by the device to other devices that utilize or dissipate it.
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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 as the fuel in particular and sometimes the oxidiser is a good coolant.
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Liquid oxygen (also LOx, LOX or Lox in the aerospace, submarine and gas industry) is the liquid form of oxygen. It has a pale blue color and is strongly paramagnetic. Liquid oxygen has a density of 1.141 g/cm³ (1.
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sources or references that appear in reliable, third-party publications. Alone, primary sources and sources affiliated with the subject of this article are not sufficient for an accurate encyclopedia article. Please include more appropriate citations from reliable sources.
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Hydrogen peroxide (H2O2) is a very pale blue liquid which appears colourless in a dilute solution, slightly more viscous than water. It is a weak acid.
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The internal combustion engine is an engine in which the combustion of fuel and an oxidizer (typically air) occurs in a confined space called a combustion chamber. This exothermic reaction creates gases at high temperature and pressure, which are permitted to expand.
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hydrogen vehicle is a vehicle that uses hydrogen as its on-board fuel for motive power. The term may refer to a personal transportation vehicle, such as an automobile, or any other vehicle that use hydrogen in a similar fashion, such as an aircraft.
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The BMW H2R ("Hydrogen Record Car") is one of the first of a new breed of racecars adapted to run on liquid hydrogen fuel. Conceived and developed in the relatively short time of 10 months, it has set nine international speed records at the Miramas Proving Grounds in France.
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Energy density is the amount of energy stored in a given system or region of space per unit volume, or per unit mass, depending on the context. In some cases it is obvious from context which quantity is most useful: for example, in rocketry, energy per unit mass is the most
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The kelvin (symbol: K) is a unit increment of temperature and is one of the seven SI base units. The Kelvin scale is a thermodynamic (absolute) temperature scale where absolute zero — the coldest possible temperature — is zero kelvins
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Recommended values for many properties of the elements, together with various references, are collected on these data pages. Any changes to the infobox data should be checked against these pages, and/or the available references should be expanded accordingly, so that the decision for or
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