Abstract: The noise of high-pressure common-rail engine and the impact of engine performances on the noise are studied. The overall noise of the prototype is measured and sound sources are identified through acoustic scan, and it is found that the front-end face, the intake side, the exhaust side and the top of the engine are the main sources of noise. So, clad steel plate is installed on the gear room, and the heat baffle of exhaust pipe and the thermal shroud of turbine shell all use noise reduction parts. These measures are very effective. Then the impact of economy and power performances of the engine on the noise is studied by adjusting the parameters of high-pressure common-rail system, and it is found that increasing the fuel consumption and reducing the torque can reduce the noise. Research results show that the engine performances have great influence on the engine noise, and the noise can be reduced at the expense of a certain percentage of economy and power performance.

Key words: Acoustic scan, Engine performance, High-pressure common-rail, Noise reduction, Overall noise