Modeling of NO sensitization of IC engines surrogate fuels auto-ignition and combustion

TL;DR

This study develops and validates a new chemical kinetic model to simulate how NOx influences auto-ignition and combustion in engine surrogate fuels, covering relevant temperature and pressure ranges.

Contribution

A novel chemical kinetic model integrating NOx effects into surrogate fuel auto-ignition mechanisms, validated against experimental data across engine-like conditions.

Findings

Model accurately predicts auto-ignition delays.

Validated across temperature and pressure ranges.

Shows NOx significantly influences combustion timing.

Abstract

This paper presents a new chemical kinetic model developed for the simulation of auto-ignition and combustion of engine surrogate fuel mixtures sensitized by the presence of NOx. The chemical mechanism is based on the PRF auto-ignition model (n-heptane/iso-octane) of Buda et al. [1] and the NO/n-butane/n-pentane model of Glaude et al. [2]. The later mechanism has been taken as a reference for the reactions of NOx with larger alcanes (n-heptane, iso-octane). A coherent two components engine fuel surrogate mechanism has been generated which accounts for the influence of NOx on auto-ignition. The mechanism has been validated for temperatures between 700 K and 1100 K and pressures between 1 and 10 atm covering the temperature and pressure ranges characteristic of engine post-oxidation thermodynamic conditions. Experiments used for validation include jet stirred reactor conditions for species evolution as a function of temperature, as well as diesel HCCI engine experiments for auto-ignition delay time measurements.