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Monopropellant Rocket Engines
Monopropellants are propellants consisting of chemicals that release energy through exothermic chemical decomposition. The molecular bond energy of the monopropellant is released usually through use of a catalyst. This can be contrasted with bipropellants that release energy through the chemical reaction between an oxidizer and a fuel. While stable under defined storage conditions, monopropellants decompose very rapidly under certain other conditions to produce a large volume of its own energetic (hot) gases for the performance of mechanical work. Although solid deflagrants such as nitrocellulose, the most commonly used propellant in firearms, could be thought of as monopropellants, the term is usually reserved for liquids in engineering literature. Uses The most common use of monopropellants is in low-impulse monopropellant rocket motors, such as reaction control thrusters, the usual propellant being hydrazine, p. 230 which is generally decomposed by exposure to an iridium, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Propellants
A propellant (or propellent) is a reaction mass, mass that is expelled or expanded in such a way as to create a thrust or another Net force, motive force in accordance with Newton's third law of motion, and "propel" a vehicle, projectile, or fluid payload. In vehicles, the engine that expels the propellant is called a reaction engine. Although technically a propellant is the reaction mass used to create thrust, the term "propellant" is often used to describe a substance which contains both the reaction mass and the fuel that holds the energy used to accelerate the reaction mass. For example, the term "propellant" is often used in Rocket engine, chemical rocket design to describe a combined fuel/propellant, although the propellants should not be confused with the fuel that is used by an engine to produce the energy that expels the propellant. Even though the byproducts of substances used as fuel are also often used as a reaction mass to create the thrust, such as with a chemical rock ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Z-Stoff
Z-Stoff (, "substance Z") was a name for calcium permanganate or sodium permanganate mixed in water. It was normally used as a catalyst for T-Stoff (high-test peroxide) in military rocket programs by Nazi Germany during World War II. Z-Stoff was used in the cold engine of the Messerschmitt Me 163 A airplane, in the earlier, self-contained HWK 109-500 ''Starthilfe'' RATO booster motor for crewed aircraft (usually in pairs or multiples of two for such uses), and a smaller derivation of the ''Starthilfe'' unit, the HWK 109-507 booster engine used with the Henschel Hs 293 anti-ship guided missile. T-Stoff decomposed by Z-Stoff was commonly used by World War II German military to generate steam for powering of fuel pumps in airplanes and rockets. The reaction produces manganese dioxide, which tends to clog the steam generators. Later generations of the Walter Rocket used solid-state catalyst instead of its water solution. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Colloidal
A colloid is a mixture in which one substance consisting of microscopically dispersed insoluble particles is suspended throughout another substance. Some definitions specify that the particles must be dispersed in a liquid, while others extend the definition to include substances like aerosols and gels. The term colloidal suspension refers unambiguously to the overall mixture (although a narrower sense of the word '' suspension'' is distinguished from colloids by larger particle size). A colloid has a dispersed phase (the suspended particles) and a continuous phase (the medium of suspension). The dispersed phase particles have a diameter of approximately 1 nanometre to 1 micrometre. Some colloids are translucent because of the Tyndall effect, which is the scattering of light by particles in the colloid. Other colloids may be opaque or have a slight color. Colloidal suspensions are the subject of interface and colloid science. This field of study began in 1845 by Frances ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diethylene Glycol Dinitrate
Diethylene glycol dinitrate (DEGDN) is an explosive nitrated alcohol ester with the formula C4H8N2O7. It is commonly used as a plasticizer in propellant or explosive formulations. While chemically similar to numerous other high explosives, pure diethylene glycol dinitrate is difficult to ignite. Ignition typically requires localized heating to the decomposition point unless the DEGDN is first atomized. It is sensitive to detonation by impact but not due to friction. Preparation and uses Diethylene glycol dinitrate can be made by nitration of diethylene glycol with nitric acid in presence of a dehydrating agent like concentrated sulfuric acid. Toxicity If ingested, like nitroglycerine, it rapidly causes vasodilation through the release of nitric oxide, a physiological signaling molecule that relaxes vascular smooth muscle which leads to a rapid loss in blood pressure. Other acute effects include convulsions and loss of consciousness. Its median lethal dose (LD50) is 650 mg/k ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Energy Density
In physics, energy density is the quotient between the amount of energy stored in a given system or contained in a given region of space and the volume of the system or region considered. Often only the ''useful'' or extractable energy is measured. It is sometimes confused with stored energy per unit mass, which is called ''specific energy'' or . There are different types of energy stored, corresponding to a particular type of reaction. In order of the typical magnitude of the energy stored, examples of reactions are: Nuclear power, nuclear, Chemical energy, chemical (including Electrochemistry, electrochemical), electrical, pressure, Deformation (engineering), material deformation or in Electromagnetic field, electromagnetic fields. Nuclear reactions take place in stars and nuclear power plants, both of which derive energy from the binding energy of nuclei. Chemical reactions are used by organisms to derive energy from food and by automobiles from the combustion of gasoline. Liqu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Specific Gravity
Relative density, also called specific gravity, is a dimensionless quantity defined as the ratio of the density (mass of a unit volume) of a substance to the density of a given reference material. Specific gravity for solids and liquids is nearly always measured with respect to water at its densest (at ); for gases, the reference is air at room temperature (). The term "relative density" (abbreviated r.d. or RD) is preferred in SI, whereas the term "specific gravity" is gradually being abandoned. If a substance's relative density is less than 1 then it is less dense than the reference; if greater than 1 then it is denser than the reference. If the relative density is exactly 1 then the densities are equal; that is, equal volumes of the two substances have the same mass. If the reference material is water, then a substance with a relative density (or specific gravity) less than 1 will float in water. For example, an ice cube, with a relative density of about 0.91, will float. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Isomer
In chemistry, isomers are molecules or polyatomic ions with identical molecular formula – that is, the same number of atoms of each element (chemistry), element – but distinct arrangements of atoms in space. ''Isomerism'' refers to the existence or possibility of isomers. Isomers do not necessarily share similar chemical property, chemical or physical property, physical properties. Two main forms of isomerism are structural isomerism, structural (or constitutional) isomerism, in which ''chemical bond, bonds'' between the atoms differ; and stereoisomerism (or spatial isomerism), in which the bonds are the same but the ''relative positions'' of the atoms differ. Isomeric relationships form a hierarchy. Two chemicals might be the same constitutional isomer, but upon deeper analysis be stereoisomers of each other. Two molecules that are the same stereoisomer as each other might be in different conformational forms or be different Isotopologue, isotopologues. The depth of analy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Otto Fuel II
Otto fuel II is a monopropellant mixture of chiefly propylene glycol dinitrate (an ester of nitric acid and propylene glycol, and structurally similar to nitroglycerin) that is used to drive torpedoes and other weapon systems. It was invented by Otto Reitlinger in 1963 (although tests with the substance had taken place before, for example in 1960). Otto fuel II, sometimes known simply as Otto fuel, is not related to the Otto cycle; it is named after Reitlinger and for being the second iteration of the fuel. It was developed by the US Navy and the first torpedo to use it was the Mark 48 torpedo in the 1960s. Properties Otto fuel II is a distinct-smelling (described by submariners as being similar in smell to methyl salicylate, wintergreen oil; i.e. sweet, fruity and minty), reddish-orange, oily liquid that is a mixture of three synthetic substances: propylene glycol dinitrate (the major component), 2-Nitrodiphenylamine, 2-nitrodiphenylamine, and dibutyl sebacate. It does not need e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PGDN
Propylene glycol dinitrate (PGDN, 1,2-propylene glycol dinitrate, or 1,2-propanediol dinitrate) is an organic chemical, an ester of nitric acid and propylene glycol. It is structurally similar to nitroglycerin, except that it has one fewer nitrate group. It is a characteristically and unpleasantly smelling colorless liquid, which decomposes at 121 °C, below its boiling point. It is flammable and explosive. It is shock-sensitive and burns with a clean flame producing water vapor, carbon monoxide, and nitrogen gas. :C3H6(ONO2)2 → 3 CO + 3 H2O + N2 The principal current use of propylene glycol dinitrate is as a propellant in Otto Fuel II, together with 2-nitrodiphenylamine and dibutyl sebacate. Otto Fuel II is used in some torpedoes as a propellant. Nitrates of polyhydric alcohols, of which propylene glycol dinitrate is an example, have been used in medicine for the treatment of angina pectoris, and as explosives since the mid-nineteenth century. PGDN affects blood pre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Submarines
A submarine (often shortened to sub) is a watercraft capable of independent operation underwater. (It differs from a submersible, which has more limited underwater capability.) The term "submarine" is also sometimes used historically or informally to refer to remotely operated vehicles and robots, or to medium-sized or smaller vessels (such as the midget submarine and the wet sub). Submarines are referred to as ''boats'' rather than ''ships'' regardless of their size. Although experimental submarines had been built earlier, submarine design took off during the 19th century, and submarines were adopted by several navies. They were first used widely during World War I (1914–1918), and are now used in many navies, large and small. Their military uses include: attacking enemy surface ships (merchant and military) or other submarines; aircraft carrier protection; blockade running; nuclear deterrence; stealth operations in denied areas when gathering intelligence and doing ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
