1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Detonation-Physical or Chemical

  1. Aug 25, 2011 #1
    1.The explosion resulting from the detonation of High explosives likes TNT ,RDX ...are they chemical reactions at all ,because the initiation requires detonation waves and no flame or oxidation as such .

    2.Detonation is followed by rapid expansion of gases accompanied by shockwaves .

    3.Can somebody throw light on the mechanics of this reaction .
  2. jcsd
  3. Aug 25, 2011 #2


    User Avatar
    Staff Emeritus
    Science Advisor

    The initial shockwave that sets off the explosion simply compresses and heats the explosive. At a certain density and temperature the explosive starts to undergo chemical reactions that release energy. Most of this energy is released as heat in the form of kinetic energy of the product particles. Like the initial shockwave, these particles heat up and compress the explosive even more, with the end result is a chain reaction that is the explosion.
  4. Aug 25, 2011 #3


    User Avatar
    Science Advisor

    Combustion requires heat, fuel, and oxidant. Fuel and oxidant are both present within the explosive. Heat is provided by compression from detonation wave.

    The process of detonation is a physical process, but the energy to drive detonation wave comes from a chemical process which is identical to that of combustion.
  5. Oct 7, 2013 #4
    Hey i'm late in my expression of gratitude but thanks you guys helped.
  6. Oct 7, 2013 #5


    User Avatar
    Gold Member

    Mechaniac, In case you would like to examine a specific kind of detonation, here's a real example used by our government:
    “The MQ-9 Reaper drone can carry up to 14 AGM-114 Hellfire air-to-ground missiles. The MQ-1 Predator can carry 2 Hellfires. Each missile carries a warhead: the AGM-114M Hellfire II warhead is the Blast fragmentation/incendiary type, and the AGM-114N Hellfire II carries the Metal augmented charge (MAC) (Thermobaric) warhead. This thermobaric weapon, which includes the type known as a "fuel-air bomb", is an explosive weapon that produces a blast wave of a significantly longer duration than those produced by condensed explosives. This is useful in military applications where its longer duration increases the numbers of casualties and causes more damage to structures.”

Share this great discussion with others via Reddit, Google+, Twitter, or Facebook