Study on Injection Characteristics of Diesel and DME

Dimethyl ether (DME) can be used as a clean high-efficiency compression ignition fuel with reduced NO_x, SO_x, CO_x and particulate matter. The subject of this work is to investigate of the injection characteristics of diesel and DME within the same specifications of injection system. The mathematical model is established for the conventional pump-pipe-nozzle fuel injection system and numerical simulation is conducted to obtain a series of injection characteristics such as injection rate, cumulative mass flow, needle valve lift, SMD, penetration, spray angle under different temperatures. The results show that the injection characteristics of DME are less affected than diesel by temperature and DME has better injection characteristics than diesel. Also, the fuel injection delay and maximum injection rate of DME are shorter and lower than those of diesel at the same injection conditions respectively.