Numerical simulation of diesel combustion based on n-heptane and toluene

Kesong Zhang ^a,b, Qiangzhi Xin ^b,*, Zhenqian Mu ^b, Zhijian Niu ^b, Zhiming Wang ^a

a. School of Energy and Power Engineering, Shandong University, Jinan City, Shandong, China
         b. Zibo Diesel Engine Company, Zibo City, Shandong, China

Abstract: Considering the self-ignition characteristic and C/H ratio, n-heptane and toluene (6:4 by mass) are chosen to constitute diesel surrogate fuel, and a reduced oxidation mechanism was developed. This mechanism was firstly validated by the combustion of diesel fuel in different oxygen concentrations within a constant volume vessel by high-speed photography. The simulated flame temperature distribution reproduces the diesel combustion process quite well. For further validation, combustion in real diesel engine was also investigated numerically and experimentally using a light duty diesel and a marine diesel. The calculated pressure curves in different operation conditions fit the measured data reasonably well. The oxidation mechanism could reproduce the main characteristics including combustion phase and NOx emission of diesel combustion in different cases.

Keywords: Diesel combustion; Reduced mechanism; n-Heptane; Toluene