ID 92

NUMERICAL ANALYSIS OF IONIZATION IN MEDIUM DUTY DIESEL ENGINE

 

Abstract:

Diesel engines have been considered to have superior power density and fuel efficiency with penalty of NOx and soot emissions. A closed loop feedback engine control strategy has proven to be one of the most promising approaches in recent years to meet stringent emission regulations. And the ion current in-cylinder sensor being more robust and durable than conventional pressure transducer proves to be ideal sensor. Extensive experimental studies have been reported; however, limited numerical research has been done on ionization in diesel engine. And current numerical approach with the assumption of virtual probe poses discrepancy over direct comparison with experiment 1: by being volume based measurement in simulation and surface based in experiment; 2: by excluding interaction with the spray. In order to resolve above ionization simulation limitation, physical probe numerical approach is being proposed in this study to enable direct comparison with experimental ion sensor probe. The comparative study between measurement of ionization with physical and virtual probe has been done at various location in combustion chamber to understand interaction of ion current sensor probe with gas dynamics, fuel spray, and variation in signal strength.