Explosion mechanical, energy

Lee, J. H. S., and I. O. Moen. 1980. The mechanism of transition from deflagration to detonation in vapor cloud explosions. Prog. Energy Combust. Sci. 6 359-389. 

The explosion efficiency is one of the major problems in the equivalency method. The explosion efficiency is used to adjust the estimate for a number of factors, including incomplete mixing with air of the combustible material and incomplete conversion of the thermal energy to mechanical energy. The explosion efficiency is empirical, with most flammable cloud estimates varying between 1 % and 10%, as reported by a number of sources. Others have reported 5%, 10%, and 15% for flammable clouds of propane, diethyl ether, and acetylene, respectively. Explosion efficiencies can also be defined for solid materials, such as ammonium nitrate. 

The final method uses thermodynamic availability to estimate the energy of explosion. Thermodynamic availability represents the maximum mechanical energy extractable from a material as it comes into equilibrium with the environment. The resulting overpressure from an explosion is a form of mechanical energy. Thus thermodynamic availability predicts a maximum upper bound to the mechanical energy available to produce an overpressure. 

FUEL. In the conventional sense, a fuel is a material or combination of materials which, when burned with air, produces heal. This heat, in turn, can he used in numerous ways—as in the conversion of water lo steam. The steam, in turn, can be used in many ways—as in a steam turbine to produce electricity, Fuels also are burned to oblain explosive or mechanical energy—as in an internal combustion engine where heal per se is an inevitable, bul undesired byproduct. The term fuel is also used in connection with nuclear reactions—as the material, such as uranium and plutonium isotopes, which undergoes fission and. in so doing, yields heat energy, Fuel also appears in the term fuel cell, in which chemical reactions other than what may be considered as conventional combustion are carried out 10 yield electrical energy. 

Study Methodology. The study leader (who bears a lot of responsibility) divides the process into a series of blocks or sections. Each section is then subjected to a brainstorming exercise when the team ponders issues of (essentially) fire, explosion, toxic release and mechanical energy release, how they might arise and the control measures required either to stop the event or cater for its consequences. The starting point for the examination of each section is a prompt from the table below. 

Early explanations about the effect of mechanical energy on the reactivity of solids are the hot-spot-model [23] and the magma-plasma-model [8]. The generation of hot-spof may be used to explain the initiation of a self-sustained reaction such as explosion, deflagration, or decomposition. Temperatures of over 1000 K on surfaces of about 1 pm2 for KM to 10-3 s can be created. These temperatures can also be found near the tip of a propagating crack [24]. Typically nonequilibrium thermodynamics are used to describe these phenomena. The magma-plasma-model allows for local nonequilibrium states on the solid surface during impact however, due to the very short time scale of 1(H s of these states only statistical thermodynamics can describe the behavior. 

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