转子叶尖间隙非定常压力场频谱分析

深入研究压缩机转子叶尖间隙非定常压力脉动,掌握其变化规律,对进一步提高压缩机效率是非常重要的.利用快速傅立叶变换技术(FFT)将转子叶尖间隙非定常压力场时域图转换成频谱图,分析了其频谱特性与转子转速、出口背压以及叶尖间隙轴向位置的关系,同时与压缩机的气动性能和气流稳定性相关联.实验表明:转子叶尖间隙非定常压力脉动主频随着转子转速的提高而增大,与出口背压无关;主频的峰值随着转速的提高而升高,随着出口背压的提高而降低;同前、后缘相比,转子叶尖中部非定常压力脉动主频的峰值在叶中较大.研究结果对研究其它旋转流场压力脉动也有参考价值.

Frequency spectrum analysis of unsteady pressure field in tip clearance unsteady flow

Thoroughly researches to unsteady pressure pulse in tip clearance flow of rotor and its changes are extremely significant to further improving the efficiency of the compressor.The time-domain wave of unsteady pressure fluctuation were transformed into frequency spectral curves by Fast Fourier Transform(FFT)in this paper to investigate the relation of rotor speed,outlet pressure and axial position to the frequency spectrum performance,associated with aerodynamic performance and flow stability of compressor.Experiments show that dominant frequency of tip clearance unsteady pressure pulsation increases with the increase of the rotor speed,but less reaction to the outlet pressure.Peak value in dominant frequency increases with the increase of the rotor speed or the decrease of the outlet pressure.Compared with the leading edges and trailing edge of blade,the peak value in dominant frequency achieves maximum at the center of bladetip.Some research results obtained could be help of understanding of pressure fluctuation effects to other rotational flow in turbomachinery.