Shock-tube spectroscopic CO and H2O measurements during 2-methyl-1-butene combustion and chemical kinetics modeling

Abstract

New CO and H2O time histories were measured for 2-Methyl-1-Butene (2M1B) behind reflected shock waves. The experimental setup was developed to simultaneously obtain carbon monoxide and water time histories from the oxidation of 2M1B in 99.5% He/Ar (20% He and 79.5% Ar). The experiments were carried out at three different equivalence ratios (ɸ = 0.5, 1.0, and 2.0) at pressures and temperatures ranging from 1.15 atm to 1.32 atm and 1414 K to 1894 K, respectively. A very limited number of studies focusing on 2M1B are available in the literature, and no model is designed specifically for this C5 alkene, as opposed to its other isomers: 1-pentene (1-C5H10), 2-pentene (2-C5H10), 3-Methyl-1-Butene (3M1B), and 2-Methyl-2-Butene (2M2B). Experimental profiles were compared to recent literature models containing a 2M1B sub-mechanism. Numerical predictions using the AramcoMech 3.0 and Ruwe et al. mechanisms show that the combustion behavior of 2M1B is not well captured by these recent detailed kinetics models. More importantly, Cheng et al. proposed a modified version of AramcoMech 3.0 with improvements on the 1-C5H10 and 2M2B sub-mechanisms, which deteriorates the mechanism's performance for 2M1B. Similarly, Power et al. had modified AramcoMech 3.0 on the sub-mechanisms for 1-C5H10 and 2-C5H10, but it does not reproduce H2O and CO time histories any better. The Dong et al. model is accurate within 10% when considering only the induction delay times, but it shows discrepancies for the concentration levels. The present study used an updated, detailed chemical kinetics model, and this mechanism was able to capture the experimental results with suitable precision, giving the best predictions.