3-D Simulation of the combustion process for di-methyl ether-fueled diesel engine
Jaeman Lim, Yongrae Kim, Sangyul Lee, Jaewoo Chung, Woo Kang, Kyoungdoug Min*
The Journal of Mechanical Science and Technology, vol. 24, no. 12, pp.2597-2604, 2010
Abstract : The characteristics of spray, auto-ignition, and the combustion process of di-methyl ether(DME) were investigated using a 3-D simulation
of a combustion vessel under various engine conditions, including high temperature and pressure. Spray impingement and nonpremixed
combustion models were incorporated into the computational fluid dynamics code, called STAR-CD. A Peng-Robinson equation
of state was introduced to calculate the evaporation rate of DME droplets that were exposed to high-pressure conditions. A Laminar
flamelet concept was used to simulate non-premixed combustion. A skeletal chemical kinetics mechanism consisting of 28 species and
45 reactions was used as the chemical mechanism for DME. Compared with the experimental data, the flamelet concept combustion
model predicted the essential features of the combustion process and auto-ignition characteristics of the DME spray reasonably well for
various initial conditions. The combustion process of a direct injection engine fueled by DME was also simulated and verified through
experimental data.
Keyword : 3-D CFD code; Flamelet model; Non-premixed combustion; NOx emissions; Reduced chemical kinetic mechanism |