离心泵内不稳定流动及流致噪声特性研究

Research on unsteady flow and noise characteristics in centrifugal pumps

为了提高船用离心泵性能和振动噪声控制目标,从而优化舰船隐蔽巡航能力,本文搭建离心泵试验台,对不同工况下泵的性能、压力脉动和流动噪声进行测量分析,通过对比试验和数值计算结果验证数值算法的准确性,结合CFD-FEM方法对船用泵内剪应力、湍动能、压力脉动和流阻及流致噪声特性进行分析。结果表明,叶片出口处壁面剪应力和湍动能较大,在叶片出口处1/3区域内摩擦阻力更大,压力脉动在叶频及其倍频处有明显峰值,呈现出明显地离散特征。内场噪声在整个频率带内表现为宽频特征,并且当频率增加,声压降低。在1000 Hz以内频段声压级能量较高,在叶片频率(241.7 Hz)及其倍频处能观察到特征峰值。总声压级随着流量的增加而呈现出先减小后增加的趋势。

In order to improve the performance and vibration noise control objectives of marine centrifugal pumps,and optimize the stealth cruise capability of ships.A marine pump test bench was built to measure and analyze the pump performance,pressure pulsation and flow noise under different working conditions.The accuracy of the numerical algorithm was verified through comparative tests and numerical calculation results.The shear stress,turbulent kinetic energy,pressure pulsation,flow resistance and flow-induced noise characteristics of marine pump were analyzed by combining CFD-FEM method.The results show that the wall shear stress and turbulent kinetic energy at the blade outlet are larger,the friction resistance in the 1/3 region at the blade outlet is larger,and the pressure pulsation has an obvious peak value at the blade frequency and its frequency doubling,showing obvious discrete characteristics.The internal field noise exhibits wideband characteristics throughout the entire frequency band,and the sound pressure level decreases with the increase of frequency.The sound pressure level energy is higher in the frequency band less than 1000 Hz,and the characteristic peak value can be observed at the blade frequency(241.7 Hz)and its frequency doubling.The total sound pressure level decreases first and then increase with the increase of flow rate.