Blast wave

In fluid dynamics, a blast wave is the increased pressure and flow resulting from the deposition of a large amount of energy in a small, very localised volume.

In simpler terms, a blast wave is an area of pressure expanding supersonically outward from an explosive core.

Sources of HE include trinitrotoluene (TNT), C-4, Semtex, nitroglycerin, and ammonium nitrate fuel oil (ANFO).

[1] The classic flow solution—the so-called Taylor–von Neumann–Sedov blast wave solution—was independently devised by John von Neumann[2][3] and British mathematician Geoffrey Ingram Taylor[4][5] during World War II.

Scientists use sophisticated mathematical models to predict how objects will respond to a blast in order to design effective barriers and safer buildings.

[14] Mach stem formation occurs when a blast wave reflects off the ground and the reflection catches up with the original shock front, therefore creating a high pressure zone that extends from the ground up to a certain point called the triple point at the edge of the blast wave.

Debris and sometimes even people can get swept up into a blast wave, causing more injuries such as penetrating wounds, impalement and broken bones.

The blast wind is the area of low pressure that causes debris and fragments to rush back towards the original explosions.

The blast wave can also cause fires or secondary explosions by a combination of the high temperatures that result from detonation and the physical destruction of fuel-containing objects.

In response to an inquiry from the British MAUD Committee, G. I. Taylor estimated the amount of energy that would be released by the explosion of an atomic bomb in air.

[16][17][18] This result allowed Taylor to estimate the nuclear yield of the Trinity test in New Mexico in 1945 using only photographs of the blast, which had been published in newspapers and magazines.

In 1950, Taylor published two articles in which he revealed the yield E of the first atomic explosion,[4][5] which had previously been classified and whose publication was therefore a source of controversy.

[19] While nuclear explosions are among the clearest examples of the destructive power of blast waves, blast waves generated by exploding conventional bombs and other weapons made from high explosives have been used as weapons of war because of their effectiveness at creating polytraumatic injury.

Improvements in vehicular and personal protective equipment have helped to reduce the incidence of blast lung.

High-speed pressure sensors and/or high speed cameras are often used to quantify the response to blast exposure.

[25] Combined with experiments, complex mathematical models have been made of the interaction of blast waves with inanimate and biological structures.