Influence of $$\text{ CF }_{3}\text{ H }$$ CF 3 H and $$\text{ CCl }_{4}$$ CCl 4 additives on acetylene detonation

• DOI: 10.1007/s00193-013-0453-8
• Publication Date: 2013-06-13T00:04:23Z
• Authors: A. Drakon; A. Emelianov; A. Eremin
• Keywords: Acetylene; Streak camera; Detonation velocity

The influence of $$\text{ CF }_{3}\text{ H }$$ and $$\text{ CCl }_{4}$$ admixtures (known as detonation suppressors for combustible mixtures) on the development of acetylene detonation was experimentally investigated in a shock tube. The time-resolved images of detonation wave development and propagation were registered using a high-speed streak camera. Shock wave velocity and pressure profiles were measured by five calibrated piezoelectric gauges and the formation of condensed particles was detected by laser light extinction. The induction time of detonation development was determined as the moment of a pressure rise at the end plate of the shock tube. It was shown that $$\text{ CF }_{3}\text{ H }$$ additive had no influence on the induction time. For $$\text{ CCl }_{4}$$ , a significant promoting effect was observed. A simplified kinetic model was suggested and characteristic rates of diacetylene $$\text{ C }_{4}\text{ H }_{2}$$ formation were estimated as the limiting stage of acetylene polymerisation. An analysis of the obtained data indicated that the promoting species is atomic chlorine formed by $$\text{ CCl }_{4}$$ pyrolysis, which interacts with acetylene and produces $$\text{ C }_{2}\text{ H }$$ radical, initiating a chain mechanism of acetylene decomposition. The results of kinetic modelling agree well with the experimental data.