Numerical investigation of the effect of APFI concept on some combustion characteristics of Turbo-Charged SI engine

Using GDI technology has a lot of challenges for automotive manufacturers such as a combustion development so PFI engines have been produced and even, in some markets, their production is increasing. Regarding to the strict emission legislations, PFI engines need improvement and using novel technologies. One of these technologies is APFI concept. This concept could approximately achieve the main advantages of GDI technology by less cost and challenges. In this study, the effect of APFI on the wall wetting, fuel distribution in combustion chamber and output power are investigated. It shows that using this concept could decrease fuel film mass on intake system about 75 percent. In the other hand, fuel distribution in combustion chamber (around spark plug) becomes homogenous which causes improvement in combustion progress and increases in-cylinder peak pressure. Investigations show that the APFI engines are sensitive to the injection timing so the optimum time for start of injection is investigated.