Theory And Developments Of The Direct Injection, Stratified Charge Combustion Engine
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This paper reviews the concepts and developments of the direct injection, stratified charge combustion engine; focusing on 4-stroke petrol commercial automotive applications.
The main objective of the direct injection (DI) stratified charge engine is to combine the benefits of the petrol spark ignition (SI) engine, controlled and complete combustion of charge at full load; and diesel compression ignition (CI) engines, lean burning and higher compression ratios and efficiencies.
Direct injection Spark Ignition (Petrol Engine)
Direct injection spark ignition (DISI) engines are relatively new to the large scale commercial market, and are slowly becoming more widespread. The demands for higher performance whilst realizing lower fuel consumption and maintaining cleaner emissions, have the potential to be met by the direct injection spark ignition engine. The thermodynamic potential of DISI engines
DISI engines have the potential to have greater fuel economy that diesel engines at partial loadings though use of stratified charge and late fuel injection; and have better performance than the naturally aspirated spark ignition engines at high loads by operating under stoichiometric or slightly rich conditions utilizing early fuel injection .
There are two basic strategies for preparing the air-fuel mixture used in direct injection technology. Figure 1 illustrates the preparation of air fuel mixtures used to optimize both partial and higher loads. At