掺氢比对阵列微管火焰燃烧噪声的影响研究

Experimental research was conducted on the direct combustion noise sound pressure level and spectral characteristics of methane/hydrogen at different mixing ratios. An array microtube burner was utilized to organize methane-hydrogen combustion under ambient temperature and pressure conditions. Within the micro-tube， spiral blades were employed to enhance the mixing of fuel and air. Pressure pulsations of combustion noise were recorded using microphones，and the data were subjected to spectral analysis. The study revealed that with an increase in the hydrogen power ratio (HPR)，the peak frequency of the combustion noise spectrum gradually shifted from low frequency to high frequency，and there was a noticeable increase in the power spectral density in the high-frequency portion. When the HPR was constant，the shape of the direct combustion noise power spectrum was not significantly affected by the equivalence ratio. Sound levels in decibels (dB) were measured using an A-weighted sound level meter. When the baseline hydrogen equivalence ratio was within the range of 0.5 to 0.8，the trend of combustion noise variation remained consistent as HPR increased from 0 to 100%，resulting in an approximate 11 dB increase in noise levels. This study fitted the direct combustion noise and obtained the prediction relationship of methane hydrogen-doped combustion noise using methane combustion noise as the normalized benchmark.