Characteristics and Properties of Blast Waves
The simplest form of a blast wave has been described and termed the Friedlander waveform. It occurs when a high explosive detonates in a free field, that is, with no surfaces nearby with which it can interact. Blast waves have properties predicted by the physics of waves. For example they can diffract through a narrow opening, and refract as they pass through materials. Like light or sound waves, when a blast wave reaches a boundary between two materials, part of it is transmitted, part of it is absorbed, and part of it is reflected. The impedances of the two materials determine how much of each occurs.
The equation for a Friedlander waveform describes the pressure of the blast wave as a function of time:
where Ps is the peak pressure and t* is the time at which the pressure first crosses the horizontal axis (before the negative phase).
Blast waves will wrap around objects and buildings. Therefore, persons or objects behind a large building are not necessarily protected from a blast that starts on the opposite side of the building. Scientists use sophisticated mathematical models to predict how objects will respond to a blast in order to design effective barriers and safer buildings.
Read more about this topic: Blast Wave
Famous quotes containing the words properties, blast and/or waves:
“The reason why men enter into society, is the preservation of their property; and the end why they choose and authorize a legislative, is, that there may be laws made, and rules set, as guards and fences to the properties of all the members of the society: to limit the power, and moderate the dominion, of every part and member of the society.”
—John Locke (1632–1704)
“Here I swear, and as I break my oath may ... eternity blast me, here I swear that never will I forgive Christianity! It is the only point on which I allow myself to encourage revenge.... Oh, how I wish I were the Antichrist, that it were mine to crush the Demon; to hurl him to his native Hell never to rise again—I expect to gratify some of this insatiable feeling in Poetry.”
—Percy Bysshe Shelley (1792–1822)
“You waves, though you dance by my feet like children at play,
Though you glow and you glance, though you purr and you dart;
In the Junes that were warmer than these are, the waves were more gay,
When I was a boy with never a crack in my heart.”
—William Butler Yeats (1865–1939)