Search results
Results from the WOW.Com Content Network
Deflagration (Lat: de + flagrare, 'to burn down') is subsonic combustion in which a pre-mixed flame propagates through an explosive or a mixture of fuel and oxidizer. [ 1 ] [ 2 ] Deflagrations in high and low explosives or fuel–oxidizer mixtures may transition to a detonation depending upon confinement and other factors.
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 (in the frame of the leading shock wave) as the reaction ceases.
The velocity of detonation is an important indicator for overall energy and power of detonation, and in particular for the brisance or shattering effect of an explosive which is due to the detonation pressure. The pressure can be calculated using Chapman-Jouguet theory from the velocity and density.
A schematic diagram of a shock wave situation with the density , velocity , and temperature indicated for each region.. The Rankine–Hugoniot conditions, also referred to as Rankine–Hugoniot jump conditions or Rankine–Hugoniot relations, describe the relationship between the states on both sides of a shock wave or a combustion wave (deflagration or detonation) in a one-dimensional flow in ...
Explosive velocity is increased with smaller particle size (i.e., increased spatial density), increased charge diameter, and increased confinement (i.e., higher pressure). [ 1 ] Typical detonation velocities for organic dust mixtures range from 1400 to 1650 m/s. [ 2 ]
In deflagration, decomposition of the explosive material is propagated by a flame front which moves relatively slowly through the explosive material, i.e. at speeds less than the speed of sound within the substance (which is usually still higher than 340 m/s or 1,220 km/h in most liquid or solid materials) [13] in contrast to detonation, which ...
A substance is characterized by a burn rate vs. pressure chart and burn rate vs temperature chart. Higher burn rate than the speed of sound in the material (usually several km/s): "detonation" A few meters per second: "deflagration" A few centimeters per second: "burn" or "smolder" 0.01 mm/s to 100 mm/s: "decomposing rapidly" to characterise it.
The same effect above the top of the cloud, where the expansion of the rising cloud pushes a layer of warm, humid, low-altitude air upwards into cold, high-altitude air, first causes the condensation of water vapour out of the air and then causes the resulting droplets to freeze, forming ice caps (or icecaps), similar in both appearance and ...