Effect of Particle Size on Detonation of Packed Bed of Aluminum Particles Saturated with Nitromethane

摘要

Detonation velocity and pressure were measured for heterogeneous mixture consisted of a packed bed of aluminum particles of different size saturated with neat nitromethane. The results of detonation velocity measurements show that critical charge diameter depends strongly on aluminum particle size. The results of pressure measurements show the existence of the extended reaction zone behind leading shock wave, which is considered to be the results of significant interplay between detonations in nitromethane in interstitial pores and shock waves in metal particles. Pressure increase due to the reaction of aluminum particle was observed behind leading shock wave. It is presented that the reaction of aluminum particle smaller than 14μm takes place within microseconds in detonation products behind leading shock wave. Post detonation effects were observed using high speed digital camera. The results of photographic observation showed that the expansion of fireball depends strongly on particle size.