rarefaction waves

Rarefaction waves are a type of wave that occurs when a medium, like a fluid or a gas, experiences a sudden decrease in pressure and density, causing it to expand and spread out. Imagine a sudden opening of a valve in a pressurized container; the gas rushes outward, creating a wave of expansion that gradually reduces pressure. These waves move faster than the speed of sound in the medium and help distribute energy and pressure changes smoothly. They are common in shock wave phenomena and are essential to understanding how sudden expansions affect fluids and gases.