Abstract
The In-Direct Injection (IDI) two-stroke cycle compression ignition engine with DME low pressure electronically controlled direct injection system is proposed to increase engine output power. It was experimentally investigated that the influence of sub-chamber volume and a cross-sectional area of connecting passage of divided-chamber on engine performance. Tests were performed under constant engine speed 1500 rpm, and DME consumption was varied. On the high load condition, the brake thermal efficiency was increased and the ignition delay was decreased as the cross-sectional area of connecting passage reduced, because the swirl in sub-chamber was enhanced. When a small sub-chamber volume was used, the ignition timing was not so delayed even though the connecting passage area was large. However, as the sub-chamber volume increased, the engine could be operated for further high load condition and the thermal efficiency was also improved because a lot of DME could be burned in sub-chamber.
