Numerical Evaluation of A Methanol Fueled Directly-Injected Engine

A numerical study on the combustion of Methanol in a directly injected (DI) engine was conducted. The study considers the effect of the bowl-in-piston (BIP) geometry, swirl ratio (SR), and relative equivalence ratio (λ), on flame propagation and burn rate of Methanol in a 4-stroke engine. Ignition-assist in this engine was accomplished by a spark plug system.

Numerical simulations of two different BIP geometries were considered. Combustion characteristics of Methanol under swirl and no-swirl conditions were investigated. In addition, the amount of injected fuel was varied in order to determine the effect of stoichiometry on combustion. Only the compression and expansion strokes were simulated. The results show that fuel-air mixing, combustion, and flame propagation was significantly enhanced when swirl was turned on. This resulted in a higher peak pressure in the cylinder, and more heat loss through the cylinder walls. In addition, the results indicate that when a stoichiometric mixture was used, incomplete combustion occurred.