Diagnosis and optimization on combustion noise of a Miller cycle gasoline engine
The"DaDa"abnormal noise of a SUV equipped with Miller cycle turbocharged gasoline engine in low speed,high load area was studied.Through Fourier transformation,filtering of the noise and vibration signal and comparison analysis of cylinder pressure spectrum,it is confirmed that the abnormal sound is 1-3.5 kHz combustion noise.Through structure analysis of the Miller cycle engine,it is found that the root cause is that high pressure rise rate caused by unreasonable advanced ignition angle under low speed and high load while throttle is fully open condition,because Miller cycle uses an inlet cam of small lift which caused short intake time and high resistance and the supercharger low-speed performance is insufficient.By optimizing the advanced ignition angle in the abnormal noise condition,the maximum pressure rise rate and 1-3.5 kHz cylinder pressure components are obviously optimized,the abnormal noise is eliminated,and the engine performance changes little.
Miller cycleCombustion noiseCylinder pressure spectrumAdvanced ignition angle
万方数据
维普
