Patent ID: 9322339
Filing Date: 2016-04-26
CPC Classification: F02B,F02D,F02M,Y02T

Claim Text:
1. A method of operating an internal combustion engine which has an engine cylinder, a piston which reciprocates within the engine cylinder and cooperates with the engine cylinder to form a combustion chamber space whose volume decreases as the piston moves inward within the engine cylinder and increases as the piston moves outward within the engine cylinder, the piston and the engine cylinder comprising confronting surfaces which, when the combustion chamber space closely approaches and finally attains minimum volume, cooperatively define a central bowl cavity which is radially bounded by an upright intermediate wall and an annular outer bowl cavity radially outward of the upright intermediate wall, and an intake system for introducing air into the combustion chamber space, the method comprising: injecting low reactivity fuel into the air to create within the combustion chamber space, a premixed air-fuel charge; when the combustion chamber space has attained substantially minimum volume, injecting high reactivity fuel directly into a central zone of the combustion chamber space which is bounded partially by the central bowl cavity and the upright intermediate wall to cause the high reactivity fuel to combust and create a flame front which propagates into an outer zone of the combustion chamber space which is bounded partially by the upright intermediate wall and the outer bowl cavity to initiate combustion of the premixed air-fuel charge in the outer zone of the combustion chamber space.