Exploring the two-stage ignition of n-butylcyclohexane: A comprehensive experimental and modeling study

Abstract

n-Butylcyclohexane (NBCH) serves as a representative surrogate fuel in investigations concerning the combustion characteristics of both jet fuels and sustainable aviation fuels. Understanding its combustion behavior and developing high-fidelity chemical reaction kinetic models are crucial for fuel performance optimization. In this study, a comprehensive investigation of the oxidation kinetics of NBCH under low-temperature conditions was conducted and a novel experimental dataset including both total and first-stage ignition delay times was proposed. A broad range of experimental conditions was investigated, spanning temperatures from 675 - 1300 K and pressures from 5 - 20 atm, under pure oxygen and air conditions, thereby providing valuable data for numerical validation. An updated chemical kinetic model was developed by integrating the comprehensive core mechanism of NUIGMech 1.3 and 30 fuel layer reaction classes. The proposed model corrected errors in the rate coefficients of key reaction classes identified in previous literature and incorporated the latest rate coefficients from theoretical calculations for specific reaction classes, demonstrating superior performance compared to literature models in accurately predicting the first-stage and total ignition delay times under various operating conditions. Additionally, the model performance was assessed through comparisons with various datasets sourced from the literature. The results showed that the updated model provides accurate predictions across a wide range of parameters. The integration of experimental results and kinetic modeling offers deep insights into the combustion processes of n-butylcyclohexane. This comprehensive approach aids in developing more efficient combustion systems and contributes to the broader understanding of fuel behavior under varied operational conditions.