The formation of five-membered rings in the combustion is of great interest due to the high reactivity and toxicity of compounds that leads these moieties1. The cyclopentadienyl radical is one of the most abundant radical present in high temperature gaseous environment such as flame. It is considered as a starting point of reaction pathways leading to formation of polycyclic aromatic hydrocarbons (PAHs) due to its multiple reaction sites and its ability of self recombination2. Qualitatively there is a large agreement that the chemistry of cyclopentadienyl radical plays a significant role in the formation of naphthalene and phenanthrene3. The kinetics of the reaction between two cyclopentadienyl radical has been the subject of several investigations since it was proposed by Melius et al.4 that it can be one of the major production pathways for naphthalene2. Dicyclopentadiene (DCPD) is a dimer of cyclopentadiene for which less chemistry is known. Ignition delay studies of dicyclopentadiene using a single pulse shock tube are being carried out behind reflected shock wave. The study is being carried out as the first step towards derivation of DCPD oxidation mechanism. The temperature and pressure ranges for the present study are 1200-1800 K and 12-19 atm, respectively. It has been observed that the ignition of dicyclopentadiene starts after 1236 K. Following figure depicts ignition delay of dicyclopentadiene measured at 1623 K. Ignition delay time studies of dicyclopentadiene/oxygen/argon mixture are being carried out for three equivalence ratios, 0.5, 1 and 1.5.
Fig: A typical signal obtained in the digital oscilloscope showing the CH emission (purple) and the pressure rise (yellow) for DCPD ignition at T=1623 K, P=17.8 atm and τ =100 µs with equivalence ratio (φ=1)
References:
1) Do Hyong Kim, James A. Mulholland, Dong Wang, and Angela Violi, Phys. Chem. A 2010, 114, 12411–12416
2) Violi, A.; Sarofim, A. F.; Truong, T. N. Flame 2001, 126, 1506-1515
3) Fascella, S.; Cavallotti, C.; Rota, R.; and Carra, S. Phys. Chem. A 2005, 109, 7546-7557
4) Melius, C. F.; Colvin, M. E.; Marinov, N. M.; Pitz, W. J.; Senkan,S. M. Combust. Inst. 1996, 26, 685–692
