It was considered that ignition of the mixture with enough concentration was controlled by the cylinder temperature but the lean mixture could only be ignited by the fuel supplied with the second injection.
(3) By the two-stage injection, the maximum value of ROHR in IDI and DI diesel engine was reduced as compared with the single-stage injections.
(4) Fuel consumption of IDI diesel engine with two-stage injection was reduced as compared with the single-stage injection.
The authors would like to express special thanks to Ishikawajima-Shibaura Machinery CO.,LTD. for their technical support. We acknowledged Mr. N. Asaoka, senior student, for his help in the experiment. Further, the fruitful suggestion and comments from Prof. K. Amagai was gratefully acknowledged.
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