Super-knock suppression using split injection in a turbo-charged GDI engine

Abstract

Super-knock, which occurs under low-speed and big load operate condition in turbo-charged gasoline direct injection (TGDI) engine, is an abnormal combustion phenomenon. Due to its potential to cause degradation of the engine, super knock has become the main obstacle for increasing specific power and lowing fuel consumption of engine. In order to investigate suppress strategies of super-knock, split injection is applied on a high boosted GDI engine. The results shows that: super knock correlates to some extent with split injection; further study shows that appropriate split injection duty ratio and the end of second injection time could reduce super knock effectively.