导叶式混流泵振动噪声的实验研究

Experimental Study on Flow-Induced Vibration and Noise of the Mixed Flow Pump With Guide Vane

导叶式混流泵叶片和导叶之间的动静干涉引起的压力脉动是诱发振动、噪声的主要来源之一。本文采用实验测试技术对泵在各个工况下的压力脉动、振动和噪声进行了测试分析。结果表明叶片通过频率是低频压力脉动和振动噪声的主频,且该频率下的压力脉动幅值对流量的变化很敏感,这是由叶轮和导叶之间的动静干涉引起的;而低频的振动和噪声变化规律与压力脉动变化规律基本一致;在叶轮二倍频和叶轮三倍频处振动噪声也出现明显的峰值,这可能是由叶轮叶片和壳体振动引起的。模型泵在额定流量工况时,由压力脉动诱发的振动和噪声较小,随着流量的减小,振动和噪声明显增大.当模型泵运行于55%额定流量点时,叶轮和导叶内出现了不稳定流动现象,诱发了强烈的机体振动和进水管路的噪声辐射。

The rotor-stator interaction between impeller and guide vane is a major source of pressure pulsation, vibration and noise in mixed flow pump with guide vane. In this paper, experiments were carried out to study the pressure fluctuation, vibration and noise characteristics at different operating conditions. The result shows that the blade passing frequency is the dominate contents of pressure fluctuation at low frequency, vibration and noise data. And the amplitude of pressure fluctuation at this frequency is very sensitive to the change of flow rate. It manifests that the fluid-structure interaction between the rotating blades and the stationary ones may be the primary disturbance source. The vibration and noise at low frequency closely follow the behavior of pressure fluctuation. The vibration and flow noise frequency spectra has obvious peak at the double harmonic frequency and the triple harmonic frequency. This may be caused by the impeller and casing vibration. At designed flow rate, the vibration and noise induced by pressure fluctuation is lower. With the decreasing of flow rate, the vibration and noise increases obviously. When the pump operates at 55% of designed flow rate, unsteady flow phenomenon appears in impeller and guide vane. As a result, it induces strong casing vibration and flow noise at inlet pipe.