Chemical Kinetics Based Equations for Ignition Delay Times of Primary Reference Fuels (Second Report)

– Ignition Process with Low Initial Temperature Beginning with Low-Temperature Oxidation –

Abstract

The ignition delay times of n-C₇H₁₆ and i-C₈H₁₈ at different fuel, O₂, and N₂ concentrations were computed using a detailed chemical kinetic model generated by KUCRS. For each fuel, the dependences of ignition delay time on fuel concentration, O₂ concentration, heat capacity per unit fuel concentration, and third body concentration were separated to establish a power law equation. For n-C₇H₁₆, ignition delay time at a high initial temperature τ_High was expressed using the scaling exponents for fuel concentration, O₂ concentration, heat capacity, and third body concentration of 0.54, 0.29, – 0.38, and 0.08, respectively, and E/R of 14300 K. Low-temperature oxidation induction time τ₁ at a low initial temperature was expressed using the scaling exponents of 0.03, 0.18, – 0.17, and 0.04, respectively, and E/R of 13800 K. Ignition delay time at a middle initial temperature was expressed as τ_Mid = B(τ_High – τ₁) + τ₁.