Marginal detonation in cyanogen/oxygen mixtures

Abstract

Velocity/composition relationships and detonation limits have been determined for the system S c =C 2 N 2 +O 2 , diluted with C 2 N 2 , O 2 , He or Ar. Limit values found are, for 1 in. diameter stainless steel tubes system moles% diluent at limit S c =C 2 N 2 51·9 ±0·1 + O 2 72·0 ±0·1 + He 82·20 ±0·1 + Ar 90·4 ±0·2 Systematic though minor fluctuations of velocity are found with the cyanogen systems, similar to those previously detected with S H =2H 2 +O 2 and S D )=2D 2 +O 2 . The system S c =C 2 N 2 shows a rise in Mach product γ M 2 on approaching the cyanogen-rich limit. This appears to be characteristic of the formation of solid detonation products, whose energy of condensation can feed back into the detonation wave under suitable conditions. Argon as diluent extends the detonation limits of cyanogen/oxygen mixtures more than does helium . Similar mass effects were previously found with fuel molecules containing hydrogen. This indicates that Soret gradients of hydrogen atoms at the detonation front are not a unique or even a very likely explanation of the mass effects observed. More probably, argon differs from helium in its role as an energy transfer catalyst.