Direct Injection Stratified Charge Engine by Impingement of Fuel Jet (OSKA)-Performance and Combustion Characteristics

A direct injection stratified charge engine using New Mixture Formation Technology (OSKA) has been developed.

Experiments on a single cylinder engine, with methanol and gasoline fuels showed the following results: 1) With methanol, the maximum IMEP was 1.3 MPa and the best indicated thermal efficiency was 46 %. 2) With gasoline, the maximum IMEP was 1.16 MPa and the best indicated thermal efficiency was 43 %.

Analysis of the cylinder pressure diagram showed the following results:

1. 1)
   High indicated thermal efficiency was observed by low time loss.
2. 2)
   A relatively short combustion duration was observed even if the engine was operated with an overall lean fuel-air mixture in the part-load condition. This fact suggests that a stratified charge was attained.
3. 3)
   From observation of the heat release rate,it will be predicted that combustion is characterized by flame propagation.