Method and automatic program for accurate thermodynamic data of reaction mechanisms for combustion modeling

Abstract

Thermodynamic parameters are the main components of reaction mechanisms for combustion modeling. In this work, the high-precision and efficient methods are investigated to calculate the thermodynamic data of enthalpies of formation, entropies, and heat capacities. An automatic program of thermodynamic data off-line calculator (TDOC) is developed for given reaction mechanisms to efficiently get high-accuracy thermodynamic parameters. It is found the extrapolation of connectivity-based hierarchy (CBH) method can broaden the scope of application for larger molecules to achieve high-accuracy calculations for enthalpies of formation at CCSD(T)/CBS level with bond additivity correction (BAC). Moreover, the high-precision thermodynamic data must consider the contributions of the hindered-rotor corrections and conformational contributions. Finally, the simulations of ignition delay time and species concentration are performed by substituting the high-precision thermodynamic parameters. It reveals that the high-precision thermodynamic parameters can improve the performance of reaction mechanisms, in which the simulated ignition delay time and species concentration are closer to experimental data. We hope this work can shed new light on the construction of reaction mechanisms for combustion modeling.