Mach wave
As a Mach wave (also Mach front , Mach-effect , Mach-reflection , Mach strain or Mach strain effect called) by Ernst Mach named, which in an exploding above the ground is bomb resulting pressure wave mentioned, which forms on the soil by the pressure wave and its reflection.
The effect is based on the fact that the reflected wave front moves in the air mass accelerated by the previous direct pressure wave and thus catches up with the direct pressure wave until both merge into a single pressure wave, which spreads almost horizontally to the earth's surface.
The air within this pressure wave reaches speeds of several 100 km / s and therefore has an enormous destructive power. This effect was consciously brought about for the first time - under operational conditions - when the atom bomb was dropped on Hiroshima on August 6, 1945. The bomb exploded at a height of about 580 meters. This effect already came into play on December 6, 1917 in the non-nuclear Halifax explosion , when the ship Mont Blanc , lying in the water, exploded and the pressure wave was reflected by the water.
Shock wave in aircraft engines
Essentially, the same effect also plays an important role in jet engines for supersonic aircraft , since here shock waves generated at the air inlet are reflected on its walls. The shaft and the air pressure must be released before the compressor. Therefore the cross-section is changed mechanically (see photo Eurofighter Typhoon ).
Shock wave from supersonic missiles
The term is often synonymous with the Mach cone used the cone-shaped, behind a supersonic describes resulting airplane or projectile and responsible for the sonic boom shock wave.
See also
literature
- Heinz M. Hiersig : Lexicon of engineering knowledge basics , Springer-Verlag, 2013, ISBN 978-3-642-95765-9 .
