Improvement of Diesel Combustion by Cooperative Fuel Spray

To decrease exhaust emissions is crucial demand nowadays, especially decrease in smoke level at late injection timings is important when intending to decrease nitrogen oxides. In this study, an effectiveness of multiple spray plumes injected near by nozzle holes on the combustion characteristics was investigated using a quiescent chamber diesel engine, aiming to improve mixture formation and combustion by the cooperative action between spray plumes under conventional fuel supply pressure. As a result, it was found that the shorter the distance between nozzle holes and the larger the diameter of nozzle holes brought more intense promotion of combustion, enabling smoke level to decrease to half of that of standard nozzle, while no decrease in power output of the engine was identified.