ディーゼルエンジンにおける燃焼衝撃のエネルギー蓄積・減衰・騒音放射

抄録

Engine noise is generally classified into the combustion noise and mechanical noise. The combustion noise level is often estimated in frequency domain using the in-cylinder pressure level and structural attenuation of the engine. The noise level in diesel engines rapidly increases near the combustion TDC and shows a great value in the expansion stroke in time-frequency domain while the in-cylinder pressure level shows a great value only near the combustion TDC. The present paper introduces an engine noise generation model which considers such time-frequency characteristics of in-cylinder pressure and engine noise and physical processes, such as combustion-impact-energy accumulation, decay and noise radiation. The effect of noise-cancelling spike combustion is also analyzed by this model.