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An explosive is a reactive substance that contains a great amount of potential energy that can produce an explosion if released suddenly, usually accompanied by the production of light, heat, sound, and pressure. An explosive charge is a measured quantity of explosive material, which may either be composed solely of one ingredient or be a mixture containing at least two substances.
A ramjet is a form of airbreathing jet engine that requires forward motion of the engine to provide air for combustion. Ramjets work most efficiently at supersonic speeds around Mach 3 and can operate up to Mach 6.
Trinitrotoluene, more commonly known as TNT, more specifically 2,4,6-trinitrotoluene, and by its preferred IUPAC name 2-methyl-1,3,5-trinitrobenzene, is a chemical compound with the formula C6H2(NO2)3CH3. TNT is occasionally used as a reagent in chemical synthesis, but it is best known as an explosive material with convenient handling properties. The explosive yield of TNT is considered to be the standard comparative convention of bombs and asteroid impacts. In chemistry, TNT is used to generate charge transfer salts.
A shaped charge is an explosive charge shaped to focus the effect of the explosive's energy. Different types of shaped charges are used for various purposes such as cutting and forming metal, initiating nuclear weapons, penetrating armor, or perforating wells in the oil and gas industry.
Pentaerythritol tetranitrate (PETN), also known as PENT, pentyl, PENTA, TEN, corpent, or penthrite, is an explosive material. It is the nitrate ester of pentaerythritol, and is structurally very similar to nitroglycerin. Penta refers to the five carbon atoms of the neopentane skeleton. PETN is a very powerful explosive material with a relative effectiveness factor of 1.66. When mixed with a plasticizer, PETN forms a plastic explosive. Along with RDX it is the main ingredient of Semtex and C4.
A depth charge is an anti-submarine warfare (ASW) weapon designed to destroy submarines by detonating in the water around the target and subjecting it to a destructive hydraulic shock. Most depth charges use high explosives with a fuze set to detonate the charge, typically at a specific depth from the surface. Depth charges can be dropped by ships, patrol aircraft and helicopters.
In explosives engineering, brisance is the shattering capability of a high explosive, determined mainly by its detonation pressure.
In physics, a shock wave, or shock, is a type of propagating disturbance that moves faster than the local speed of sound in the medium. Like an ordinary wave, a shock wave carries energy and can propagate through a medium but is characterized by an abrupt, nearly discontinuous, change in pressure, temperature, and density of the medium.
Detonation is a type of combustion involving a supersonic exothermic front accelerating through a medium that eventually drives a shock front propagating directly in front of it. Detonations propagate supersonically through shock waves with speeds in the range of 1 km/sec and differ from deflagrations which have subsonic flame speeds in the range of 1 m/sec. Detonation is an explosion of fuel-air mixture. Compared to deflagration, detonation doesn't need to have an external oxidizer. Oxidizers and fuel mix when deflagration occurs. Detonation is more destructive than deflagrations. In detonation, flame front travels through air-fuel faster than sound, while in deflagrations, flame front travels through air-fuel slower than sound
The exploding-bridgewire detonator is a type of detonator used to initiate the detonation reaction in explosive materials, similar to a blasting cap because it is fired using an electric current. EBWs use a different physical mechanism than blasting caps, using more electricity delivered much more rapidly. Exploding with more precise timing after the electric current is applied, by the process of exploding wire method. This has led to their common use in nuclear weapons.
The shock tube is an instrument used to replicate and direct blast waves at a sensor or a model in order to simulate actual explosions and their effects, usually on a smaller scale. Shock tubes can also be used to study aerodynamic flow under a wide range of temperatures and pressures that are difficult to obtain in other types of testing facilities. Shock tubes are also used to investigate compressible flow phenomena and gas phase combustion reactions. More recently, shock tubes have been used in biomedical research to study how biological specimens are affected by blast waves.
FOX-7 or 1,1-diamino-2,2-dinitroethylene(DADNE) is an insensitive high explosive compound. It was first synthesized in 1998 by the Swedish National Defence Research Institute (FOS). The name FOX-7 is derived from the acronym of the Swedish Defence Research Agency (FOI), with the I replaced by an X to indicate an explosive, as in RDX and HMX.
Shock hardening is a process used to strengthen metals and alloys, wherein a shock wave produces atomic-scale defects in the material's crystalline structure. As in cold work, these defects interfere with the normal processes by which metallic materials yield (plasticity), making materials stiffer, but more brittle. When compared to traditional cold work, such an extremely rapid process results in a different class of defect, producing a much harder material for a given change in shape. If the shock wave applies too great a force for too long, however, the rarefaction front that follows it can form voids in the material due to hydrostatic tension, weakening the material and often causing it to spall. Since voids nucleate at large defects, such as oxide inclusions and grain boundaries, high-purity samples with a large grain size are able to withstand greater shock without spalling, and can therefore be made much harder.
Explosive velocity, also known as detonation velocity or velocity of detonation (VoD), is the velocity at which the shock wave front travels through a detonated explosive. Explosive velocities are always faster than the local speed of sound in the material.
The Chapman–Jouguet condition holds approximately in detonation waves in high explosives. It states that the detonation propagates at a velocity at which the reacting gases just reach sonic velocity as the reaction ceases.
PLX, abbreviation of Picatinny Liquid Explosive, is a liquid binary explosive. It is a mixture of 95% nitromethane (NM) along with 5% ethylene diamine (EDA) as a sensitizer. Other amine compounds can be used instead of ethylene diamine, such as triethylene tetramine, diethylenetriamine or ethanolamine, but EDA has been found to be the most effective amine additive. PLX is a fairly powerful high explosive, marginally exceeding the destructive yield of TNT.
The Voitenko compressor is a shaped charge adapted from its original purpose of piercing thick steel armour to the task of accelerating shock waves. It was proposed by Anatoly Emelyanovich Voitenko, a Soviet scientist, in 1964. It slightly resembles a wind tunnel.
An explosion is a rapid expansion in volume of a given amount of matter associated with an extreme outward release of energy, usually with the generation of high temperatures and release of high-pressure gases. Explosions may also be generated by a slower expansion that would normally not be forceful, but is not allowed to expand, so that when whatever is containing the expansion is broken by the pressure that builds as the matter inside tries to expand, the matter expands forcefully. An example of this is a volcanic eruption created by the expansion of magma in a magma chamber as it rises to the surface. Supersonic explosions created by high explosives are known as detonations and travel through shock waves. Subsonic explosions are created by low explosives through a slower combustion process known as deflagration.
The Gurney equations are a set of mathematical formulas used in explosives engineering to relate how fast an explosive will accelerate an adjacent layer of metal or other material when the explosive detonates. This determines how fast fragments are released by military explosives, how quickly shaped charge explosives accelerate their liners inwards, and in other calculations such as explosive welding where explosives force two metal sheets together and bond them.
TEX is a dense nitramine high explosive, that derives from the very powerful and sensitive high explosive CL-20. Though related to CL-20 in that is shares the same cage structure, TEX is more easily synthesized in good yield from inexpensive starting materials. Unlike CL-20, TEX is friction insensitive, bears a low impact sensitivity, and possesses a very low shock sensitivity and large critical diameter, making it an interesting explosive filler for insensitive munitions. Its systematic name, 4,10-dinitro-2,6,8,12-tetraoxa-4,10-diazatetracyclo[5.5.0.05,9.03,11]-dodecane derives from its tetracyclic structure.
References
- ↑ Cooper, Paul W. (1996). Explosives Engineering, New York: Wiley-VCH. ISBN 0-471-18636-8
- ↑ Shevchenko, A. A.; Dolgoborodov, A Yu; Brazhnikov, M. A.; Kirilenko, V. G. (2018). "Pseudoideal detonation of mechanoactivated mixtures of ammonium perchlorate with nanoaluminum". Journal of Physics: Conference Series. 946 (1): 012055. Bibcode:2018JPhCS.946a2055S. doi: 10.1088/1742-6596/946/1/012055 .
- ↑ Kozak, G.D. (1998). "Measurement and calculation of the ideal detonation velocity for liquid nitrocompounds". Combust Explos Shock Waves. 34 (5): 584. doi:10.1007/BF02672682. S2CID 98738029.
- ↑ Bolton, O.; Simke, L. R.; Pagoria, P. F.; Matzger, A. J. (2012). "High Power Explosive with Good Sensitivity: A 2:1 Cocrystal of CL-20:HMX". Crystal Growth & Design. 12 (9): 4311. doi:10.1021/cg3010882.
- ↑ Viswanath DS, Ghosh TK, Boddu VM. (2018) 5-Nitro-2,4-Dihydro-3H-1,2,4-Triazole-3-One (NTO). Chapter 5 in Emerging Energetic Materials: Synthesis, Physicochemical, and Detonation Properties. Springer. doi : 10.1007/978-94-024-1201-7_5
- ↑ "Data" (PDF). www.dtic.mil. Retrieved 2019-12-15.[ dead link ]