Ion current detection in a Diesel engine fueled with a Diesel/RME blend: positively/negatively polarized Ion-Probe faced to piston bowl center

In this report the results of an experimental study carried out on a 3-cylinder diesel engine running at different speed and load conditions are presented. Experiments were mainly aimed for investigating on possible information on combustion development obtainable from ionization current detected by a polarized sensor during combustion. The engine is equipped with an in-cylinder pressure sensor mounted in a glow-plug adapter; furthermore, a three-axis linear accelerometer is mounted on engine block in proximity of the same instrumented cylinder. Signals are sampled and stored via a powerful time-based data acquisition system that allows to acquire a continuous series of engine cycles at high sampling rate. The engine was controlled by an own commercial control unit.