Thermochemical Characteristics of Dimethyl Ether - An Alternative Fuel for Compression-Ignition Engines

This paper analyzed chemical and thermophysical properties of dimethyl ether (DME) as an alternative fuel for compression-ignition engines. On the basis of the chemical structure of DME and the molecular thermodynamics of fluids, equations have been developed for most of the DME thermophysical properties that would influence the fuel-system performance. These equations are easy to use and accurate in the pressure and temperature ranges for CI engine applications. The paper also pointed out that the DME spray in the engine cylinder would differ significantly from that of diesel fuel due to the thermodynamic characteristics of DME. The DME spray pattern will affect the mixing and combustion processes in the engine cylinder, which, in turn, will influence emissions from combustion.