Future stringent legislation on emissions in combination with the market request of an increase in engine efficiency and optimization poses a great challenge to the engine and components manufacturers. The technologies developed in the last years for Spark Ignition (SI) engines such as turbocharging and variable valve actuation are not able to totally satisfy the future normative. More progress stilt has to be mode in terms of in-cylinder combustion process and efficiency. The aim of this paper is the optimisation of a boosted SI engine in terms of performance, fuel consumption and pollutants emissions with low costs. The experimental activity was carried out on a port fuel Injection SI optical engine, equipped with a commercial four-valve head. Innovative injection strategies were tested: in particular, single and double injections were performed when the intake valves were open. Optical techniques based on 2D-digital imaging were used lo follow the fuel injection in the intake manifold and simultaneously the flame propagation in the combustion chamber. Conventional measurements of engine parameters and exhaust emissions completed the experimental investigations. The tests demonstrated that the double injection strategies were characterized by higher combustion process efficiency than single injection on. The injection splitting resulted a suitable solution for the reduction in pollutants concentration in the combustion chamber and at the exhaust with a good compromise between performance and fuel consumption.
Effect of the fuel injection splitting on the combustion process in a PFI boosted spark-ignition engine
Merola SS;Sementa P;Tornatore C;Vaglieco BM
2008
Abstract
Future stringent legislation on emissions in combination with the market request of an increase in engine efficiency and optimization poses a great challenge to the engine and components manufacturers. The technologies developed in the last years for Spark Ignition (SI) engines such as turbocharging and variable valve actuation are not able to totally satisfy the future normative. More progress stilt has to be mode in terms of in-cylinder combustion process and efficiency. The aim of this paper is the optimisation of a boosted SI engine in terms of performance, fuel consumption and pollutants emissions with low costs. The experimental activity was carried out on a port fuel Injection SI optical engine, equipped with a commercial four-valve head. Innovative injection strategies were tested: in particular, single and double injections were performed when the intake valves were open. Optical techniques based on 2D-digital imaging were used lo follow the fuel injection in the intake manifold and simultaneously the flame propagation in the combustion chamber. Conventional measurements of engine parameters and exhaust emissions completed the experimental investigations. The tests demonstrated that the double injection strategies were characterized by higher combustion process efficiency than single injection on. The injection splitting resulted a suitable solution for the reduction in pollutants concentration in the combustion chamber and at the exhaust with a good compromise between performance and fuel consumption.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
