Introduction to Accurate Modelling of an Injector for Common Rail Systems
It is well known that the injection system plays a leading role in achieving high diesel engine performance; the introduction of the common rail fuel injection system (Boehner & Kumel, 1997; Schommers et al., 2000; Stumpp & Ricco, 1996) represented a major evolutionary step that allowed the diesel engine to reach high efficiency and low emissions in a wide range of load conditions. Many experimental works show the positive effects of splitting the injection process in several pilot, main and post injections on the reduction of noise, soot and NOx emission (Badami et al., 2002; Brusca et al., 2002; Henelin et al., 2002; Park et al., 2004; Schmid et al., 2002). In addition, the success of engine downsizing (Beatrice et al., 2003) and homogeneous charge combustion engines (HCCI) (Canakci & Reitz, 2004; Yamane & Shimamoto, 2002) is deeply connected with the injection system performance and injection strategy. However, the development of a high performance common rail injection system requires a considerable investment in terms of time, as well as money, due to the need of fine tuning the operation of its components and, in particular, of the electronic fuel injector. In this light, numerical simulation models represent a crucial tool for reducing the amount of experiments needed to reach the final product configuration.…