An improved 3-pentanone high temperature kinetic model using Bayesian optimization algorithm based on ignition delay times, flame speeds and species profiles

A 3-pentanone (diethyl ketone, DEK) high temperature kinetic model (HUST_Model) was improved based on the model proposed by Sun et al. (Sun_Model) in the present study. The main updated reactions are as following: the reaction rate constants of the DEK H-atom abstraction reactions by H(O) over dot(2), (O) over dotH and O-2 were obtained by analogy with butanone due to the similarities in the molecular structure, and the rate constants of two DEK decomposition reactions were obtained from the works of Dames et al. (Dames_Model). Moreover, the ignition delay times (IDTs) of DEK were measured at pressures of 2.65 bar and 10 bar; equivalence ratios (phi) of 0.5 and 2.0; and temperatures in the range of 1100-1500 K. The rate coefficients of DEK H-atom abstraction reactions by HO2, OH, O-2 and DEK decomposition reactions can be optimized by Bayesian Optimization algorithm using a very large number of experimental data from the literatures, including IDTs, flame speeds and species profiles, and IDTs measured in the present study. The experimental data of the IDTs and the flame speeds were used for the optimization of HUST_Model, and those of the species profiles for the validation of the optimized HUST_Model. The branching ratios of these four pairs of reactions were maintained unchanged during the optimization process. The results of the evaluation and validation show that the performance of HUST_Model is much better than Dames_Model and Sun_Model not only for the prediction of the IDTs and the flame speeds, but also for the prediction of the species profiles, especially the CH3 profiles. The comparisons of HUST_Model with Dames_Model and Sun_Model were conducted by the sensitivity analysis and reaction flux analysis for the predictions of the IDTs, the flame speeds and the CH3 profiles. The results of the comparison and analysis show that, the global optimization of the reaction rate constants of DEK H-atom abstraction reactions by H(O) over dot(2), (O) over dotH, O-2 and DEK decomposition reactions in HUST_Model by the BOA is reasonable and reliable.