Detonating gas

Definitions

  • Webster's Revised Unabridged Dictionary
    • Detonating gas a mixture of two volumes of hydrogen with one volume of oxygen, which explodes with a loud report upon ignition.
    • ***

Usage


In news:

Gas grenade detonation injures 3 in Midlothian.
In a scene reminiscent of a James Bond film, the boat is slowly filled with gas while a sailor in a nearby vessel holds his finger over the detonator, ready to blow the floating target sky high.
***

In science:

Roughly speaking, detonations are compressive waves analogous to shock waves in nonreactive gas dynamics, while deflagrations are expansive solutions analogous to rarefactions; for a fixed left-hand state, there are weak and strong branches of right-hand sides corresponding to waves of each type.
A stability index for detonation waves in Majda's model for reacting flow
Indeed, there is a band of speeds (s∗ , s∗ ) about the characteristic speed f ′ (u+ ) for which neither detonation nor deflagration connections exist, in sharp contrast to the inert-gas, shock wave case.
A stability index for detonation waves in Majda's model for reacting flow
For uL ≤ uC J , the solution consists of a (possibly zero strength) gas-dynamical rarefaction from uL to uC J , followed by a Chapman–Jouget detonation from uC J to uR .
A stability index for detonation waves in Majda's model for reacting flow
Denote by u∗ ≤ uC J the special left state u− that is connected to uR by a nondegenerate weak detonation profile with speed s∗ , and u∗ ≥ uC J the corresponding value of u− : i.e., the unique state that is connected to u∗ by a gas-dynamical shock with the same speed s∗ .
A stability index for detonation waves in Majda's model for reacting flow
By the discussion of the previous case, the only possible solution is a gas-dynamical shock from uL to u1 , followed by a weak detonation from u− = u1 to u+ = uR having the special property u+ ≤ ui < u− < ui ≤ uL ≤ u− .
A stability index for detonation waves in Majda's model for reacting flow
***