In Action movies, I have seen a couple of times that if flammable gases or liquids like benzene are ignited, the fire spreads out within fraction of a second and sometimes there is also an explosion. However, if a Piece of wood in a grill is lightened, it may take minutes if the fire has the full Magnitude. Why there is a difference in ignition Speeds (what is the physical cause)?

Are there kinetic equations how to determine the Speed how fast a fire would spread out?

I am interested in the viewpoint of thermodynamics how to derive the Speed of ignition.

  • 5
    $\begingroup$ Frankly, thermodynamics doesn't help understand the kinetics much at all. While a piece of wood gently burning in the fireplace and a propane tank undergoing a BLEVE (boiling liquid expanding vapor explosion) are both doing something thermodynamically preferred, the kinetics matter a lot. $\endgroup$ – Jon Custer Jul 10 '18 at 15:27

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Browse other questions tagged or ask your own question.