Early Oxidation Kinetics of N-Dodecane under High-Temperature Conditions

Area of Science:

• Chemical Kinetics
• Combustion Science
• Aerospace Engineering

Background:

• n-Dodecane (C12H26) is a critical surrogate fuel for aviation kerosene in high-performance aero engines.
• Understanding high-temperature combustion kinetics of n-dodecane is vital for aerospace applications.

Purpose of the Study:

• To investigate the high-temperature oxidation mechanism of n-dodecane using first-principles molecular dynamics.
• To elucidate the early oxidation pathways and identify key reaction types and species involved.

Main Methods:

• Employed first-principles molecular dynamics (MD) simulations.
• Analyzed the oxidation process of n-dodecane at temperatures above the critical point.

Main Results:

• n-Dodecane oxidizes to form oxygenated C12 species with C═O, -OH, -O-, and -COOH groups, releasing significant energy.
• Identified four primary reaction types before C-C bond dissociation: H-abstraction, H-addition, intramolecular H transfer, and O-addition.
• H-abstraction and O-addition reactions were found to occur with the highest frequencies, with O2 molecules and various radicals playing crucial roles.

Conclusions:

• This research provides the first detailed investigation into the early oxidation reaction mechanism of n-dodecane.
• Offers novel insights into the complex oxidation kinetics of long-chain alkanes, relevant for aviation fuel combustion.