Effect of Molecular Structure on Laminar Flame Speeds of Three C₅ Alkenes

ABSTRACT

The laminar flame speeds of 1-pentene and 2-methyl-2-butene are measured in our previous studies. In order to study the effect of molecular structure on the combustion characteristics of C₅ alkenes, the laminar flame speeds of 2-pentene/air mixtures were measured in a constant volume combustion bomb in the different conditions (T₀ = 450 K, p = 0.1/0.3 MPa, and φ = 0.6–1.6). Experimental results for the three fuels show that 1-pentene has the largest laminar flame speeds, and 2-methyl-2-butene has the lowest one. Further, a high-temperature chemical mechanism for C₅ alkenes was developed to analyze the differences in laminar flame speeds between the three fuels and to explore the effects of molecular structure on the combustion characteristics of the three C₅ alkenes. The chemical mechanism was verified by the experimental results of laminar flame speeds and can well predict the combustion characteristics of these three C₅ alkenes over a wide range of conditions. The effects of molecular structure on laminar flame speed were analyzed by the chemical kinetic model from three aspects: bond dissociation energies, reaction pathways, and sensitivity analyses. Results show that the chemical kinetic characteristics of linear 1-pentene and 2-pentene are similar to each other, while the chemical kinetic characteristics of branched 2-methyl-2-butene differ greatly from them.

KEYWORDS:

• C₅ alkene
• laminar flame speed
• high temperature combustion
• chemical kinetic model

Additional information

Funding

This work was supported by the National Natural Science Foundation of China under Grant [No. 91441113].