What distinguishes a deflagration from a detonation?

Deflagration is characterized by a combustion process that propagates through a medium at a speed slower than that of sound in that medium. This results in a lower pressure wave and less violent energy release compared to detonation. Typically, deflagrations occur at subsonic speeds, which is a defining feature of the process.

In contrast, detonation involves a rapid expansion of gases and a shock wave that travels faster than the speed of sound in the same medium. The initiation of detonation leads to a much more violent and instantaneous energy release, making it fundamentally different from deflagration.

Thus, the distinction made is not only about the speed differences but also about the nature of the reaction and the resultant pressure wave from each type of explosion. This understanding is crucial in fire investigation, as it helps professionals assess the nature and cause of an explosion accurately, leading to more precise conclusions during investigations.