Smoke Prediction for Turbocharged DI Diesel Engine During Free Acceleration

Abstract

Direct Injection types of diesel engines are becoming popular because of their fuel economy as well as low exhaust emissions. However, they emit higher amount of visible exhaust termed as smoke. A turbocharged diesel engine was selected for investigation purpose during this work to study its peculiar smoke behavior during steady state and transient operation. Experimental study was carried out to collect performance and combustion related data. One dimensional simulation model was setup and validated for steady state operation. The same model was further used to predict the transient behavior of the engine. A methodology was established for carrying out transient simulation using one-dimensional modeling. Effect of various fuel injection and combustion parameters on transient behavior was studied. The experimental study and simulation work showed that the turbocharged engine emitted higher smoke during transient condition as compared to steady state. The main reason was attributed to lower air-fuel ratio. It was also observed that the control on fuel flow during transient operation is important to reduce smoke.