The paper describes basic investigations towards identifying optimum specifications of fuel injection and combustion system parameters for a new alternative fuel, Dimethylether (DME), allowing liquid direct injection, compression ignition and smokeless combustion.
Special emphasis is drawn on fuel injection equipment (FIE) parameter optimization using new development tools such as simulation techniques of the fuel system hydraulics and numerical identification methods to determine sofar unknown fuel data and flow phenomena of the new alternative fuel.
Combustion system parameters are analyzed on a single cylinder test engine with respect to efficiency, gaseous emissions, and noise. Due to the particular properties of the fuel the engine parameter optimization was concentrated on new directions of system development thus allowing new solutions for FIE and combustion system, as described in this paper.
The new alternative fuel DME shows very promising results with respect to emissions (ULEV level is achievable without catalyst), efficiency (energy equivalent BSFC is comparable to DI diesel engines), durability (no ignition aid is needed and low fuel injection pressures are possible) and comfortable combustion noise.