单级低速轴流压气机噪声特性实验研究

In order to analyze the noise characteristic of a single-stage low-speed axial compressor under various working condition, the upstream propagating noise was measured by an in-duct sensory array which consisted of 20 equally spaced microphones.Then the spectrum was obtained.The circumferential modal amplitudes were calculated by utilizing mode detection technique.The experimental results were compared with Tyler and Sofrin’s duct mode theory.According to the result, it can be noted that the sound pressure level of the noise at first and second blade passing frequency (BPF) was very high.However, this kind of noise was thought to be cut-off according to Tyler and Sofrin’s theory.Sound modal analysis revealed that new generation mechanisms of sound mode at 1BPF and 2BPF are exist in these low-speed compressors.