What is described as a reaction that travels through air at subsonic velocities?

Deflagration refers to a rapid reaction that occurs at subsonic speeds, typically resulting in the combustion of a fuel in the presence of an oxidizer. In this process, the combustion wave travels through the gas mixture at a velocity slower than the speed of sound in that medium, creating a thermal wave instead of a shock wave. This type of reaction is characterized by a gradual buildup of heat and pressure that can lead to flames spreading through the material.

Deflagration is differentiated from detonation, which involves a supersonic reaction that produces a shock wave, thereby leading to a more explosive effect. Flashover and combustion, while related to the broader context of fire dynamics, do not specifically describe the characteristics of a reaction that propagates through air at subsonic velocities in the same way that deflagration does. Understanding this difference is essential for fire investigation technicians as it aids in analyzing fire dynamics and the behavior of materials during combustion.