rarefaction

Examples of rarefaction in the following topics:

• Detonation Waves

  • The front must be followed by a rarefaction wave that travels up the tube at the speed of sound through the postshock gas.
  • If the postshock gas is traveling subsonically relatively to the shock then the rarefaction wave will eventually catch up to the back of the shock reducing the flux through the shock by reducing the postshock pressure and shock velocity relative to the preshock gas until the minimum flux is achieved.
  • At this point the postshock gas leaves the front at the sound speed so the rarefaction wave no longer overtakes the shock and the combined detonation front and rarefaction wave achieves a steady state.

• Longitudinal Waves

  • Longitudinal sound waves are waves of alternating pressure deviations from the equilibrium pressure, causing local regions of compression and rarefaction.

• Real Sound Waves

  • If $a<0$ a rarefaction wave travels through the gas.
  • The Characteristic Structure for a Rarefaction Wave, a < 0.