Investigation of the Fuel Distribution and the In-cylinder Flow Field in a Stratified Charge Engine Using Laser Techniques and Comparison with CFD-Modelling
This paper presents an investigation of a Volvo Direct Injection Spark Ignition (DISI) engine, where the fuel distribution and the in-cylinder flow field have been mapped by the use of laser techniques in an engine with optical access. Along with the experimental work, CFD-modelling of flow and fuel distribution has been performed. Laser Induced Fluorescence (LIF) visualisation of the fuel distribution in a DI-engine has been performed using an endoscopic detection system. Due to the complex piston crown geometry it was not possible to monitor the critical area around the sparkplug with conventional, through the piston, detection. Therefore, an endoscope inserted in the spark plug hole was used. This approach gave an unrestricted view over the desired area. In addition, the in-cylinder flow fields have been monitored by Particle Image Velocimetry (PIV) through cylinder and piston. The results from both the LIF and the PIV measurements have been compared with CFD-modelling at Volvo.