Development of a Highly Compact and Robust Chemical Reaction Mechanism for Unsaturated Furan Oxidation in Internal Combustion Engines via a Multiobjective Genetic Algorithm and Generalized Polynomial Chaos

Abstract

This work focuses on the development of a highly compact and robust chemical reaction mechanism for unsaturated furan oxidation in internal combustion engines. Recently, furans have gathered much attention in the research community as they are second-generation biofuels that do not compete with food supplies, unlike first-generation biofuels. Moreover, they are oxygenated and highly resistant to knocking when compressed. A four-component chemical reaction mechanism, consisting of furan, 2-methylfuran, 2,5-dimethylfuran, and toluene, is developed to simulate the combustion of unsaturated furans under engine-relevant conditions. First, a detailed furan, 2-methylfuran, and 2,5-dimethylfuran reaction mechanism from the literature is selected and reduced under engine-relevant conditions. Sensitivity analysis and the species rate of production are employed to identify the major reaction pathways of the respective furanic components under different conditions. After which, isomer lumping and reaction lumping are used to further reduce the size of the major reaction pathways and the skeletal major reaction pathways for furan, 2-methylfuran, and 2,5-dimethylfuran are included to a compact toluene base mechanism from the literature to form the final mechanism, consisting of only 62 species among 228 reactions. Subsequently, the pre-exponential A factors in Arrhenius equations of the furanic reactions are optimized via an in-house multiobjective nondominated sorting genetic algorithm, and successively, the generalized polynomial chaos is introduced to model the uncertainty of the input rate coefficient and its propagation in ignition behavior. The performance of the different furanic components in the mechanism is then validated against experimental data from the literature. The predicted results are in reasonable agreement with experimental results considering the compact size of the developed mechanism and the challenge of multiobjective optimization.

Construction and validation of a reduced mechanism in a diesel engine fueled with 2-methylfuran-diesel

“…The new mechanism verified in detail the relationships of the mole fractions of reactants, products, stable and active intermediates with the flame distance of the burner [12][13][14]. Tian et al [15] [16][17][18][19][20].…”

Fast Retrieval Method of Portal Information Based on a Chaotic Genetic Algorithm

“…In order to ensure the accuracy of retrieval, in the process of retrieving portal information under massive data, it is necessary to extract relevant features of the portal information, and the features of the portal information usually consist of multiple dimensions, which will make the process of retrieving portal information too complicated and complex, which reduces the accuracy of retrieving web portal information [7]. Since the portal website information dimension contains a lot of redundant data [8], it is necessary to reduce the portal website information dimension and retain the main feature information to eliminate the influence of redundant data. e specific methods are as follows:…”

Construction of a Skeletal Oxidation Mechanism for 2,5-Dimethylfuran Using Decoupling Methodology and Reaction Class-Based Global Sensitivity Analysis

“…In this research, a compact skeletal mechanism for DMF is obtained automatically using the reaction class-based global sensitivity and path sensitivity analyses (RC-GSPSA) and the decoupling methodology. Compared with other construction methods of reduced mechanisms, ,, the operator’s experience is considerably reduced during the reduction process in the present study. For the present method, only the following steps are required by manual operations, which includes choosing the reduction and optimization targets and the test conditions and dividing the reactions in the fuel submechanism into different classes.…”

“…However, discrepancies exist between the experimental and calculated species profiles in JSRs. By integrating the reduced furan, 2methylfuran, and DMF submechanisms into a skeletal toluene mechanism, 46 Tay et al 47 built a four-component reduced mechanism, consisting of 62 species and 228 reactions. The reduced mechanism was assessed with the measurements from shock tubes, JSRs, and laminar flame speeds.…”