Implosion (mechanical process)

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For other uses, see implosion (disambiguation).
In an explosion (top), force radiates away from a source. With implosion (bottom), the object collapses upon itself (generally being crushed by an outside force).

Implosion is a process in which objects are destroyed by collapsing in on themselves. The opposite of explosion, implosion concentrates matter and energy. An example of implosion is a submarine being crushed from the outside by the hydrostatic pressure of the surrounding water.

Contents

  • 1 Nuclear weapons
  • 2 Fluid dynamics
  • 3 Astrophysics
  • 4 Controlled structure demolition
  • 5 See also
  • 6 External links

[edit] Nuclear weapons

In an implosion-type nuclear weapon design, a sphere of plutonium, uranium, or other material is imploded by a spherical arrangement of explosive charges, decreasing the volume and therefore increasing the density by a factor 2 to 4, making the mass critical, resulting in a nuclear explosion. In some forms of thermonuclear weapons, the energy from this explosion is then used to implode a capsule of fusion fuel before igniting it, causing a fusion reaction (see Teller–Ulam design).

[edit] Fluid dynamics

In the context of fluid dynamics, implosion was a term used by Victor Schauberger to describe the suctional process that causes matter to move inwards, not outwards as is the case with explosion. This inward (centripetal) motion, however, does not follow a straight (radial) path to the centre; it follows a spiralling, whirling path. This is called a vortex. This usage is unique to Schauberger, whose theories are not widely accepted by scientists.

Cavitation also is an implosion process, in which low pressure areas of a water propeller cause the momentary creation of a vapor bubble, which quickly collapses. This collapse can cause extremely high local acoustic pressures that can cause local spalling and thus the erosion of the surface of the propellor or nearby structures. Similar problems can occur in conduits for high speed water flow as in the power generation and overflow structures of dams and in water pumps and associated piping.

[edit] Astrophysics

Implosion is a key part of the gravitational collapse of large stars., which can lead to the creation of supernovae, neutron stars and black holes.

[edit] Controlled structure demolition

Main article: Building implosion

Large buildings of various structural types such as masonry, steel frame, or reenforced concrete may be reduced to an easily removed pile of rubble by selective destruction of supporting elements by sequenced and confined explosions. The goal is to confine the materials to specific areas, usually to avoid harm to nearby structures. The technique involves the firing precisely placed demolition charges in specific timed intervals that use gravity to cause the center of the building to fall vertically while simultaneously pulling the sides inward, a process often described as an implosion.