• CN:11-2187/TH
  • ISSN:0577-6686

机械工程学报 ›› 2019, Vol. 55 ›› Issue (8): 225-232.doi: 10.3901/JME.2019.08.225

• 交叉与前沿 • 上一篇    

叶栅内压力脉动特性及其对流致噪声的影响

李仁年1,2, 李瑾1, 权辉1,2, 葸鹏3, 傅百恒1   

  1. 1. 兰州理工大学能源与动力工程学院 兰州 730050;
    2. 甘肃省流体机械及系统重点实验室 兰州 730050;
    3. 利欧集团(浙江)泵业有限公司 台州 317500
  • 收稿日期:2018-07-05 修回日期:2018-11-05 出版日期:2019-04-20 发布日期:2019-04-20
  • 作者简介:李仁年,男,1963年出生,教授,博士研究生导师,主要从事流体机械多相流理论及应用研究。E-mail:lirn@lut.cn
  • 基金资助:
    国家自然科学基金(51579125,51609113)、甘肃省自然科学基金项目(2017GS10829)、中国博士后基金(2018M633651XB)和兰州理工大学红柳优秀青年人才资助项目。

Pressure Pulsation Characteristics of the Cascade and Its Impact on Flow-induced Noise

LI Rennian1,2, LI Jin1, QUAN Hui1,2, XI Peng3, FU Baiheng1   

  1. 1. School of Energy and Power Engineering, Lanzhou University of Technology, Lanzhou 730050;
    2. Gansu Provincial Key Laboratory of Fluid machinery and Systems, Lanzhou 730050;
    3. LEO Group Pump(Zhejiang) Company Limited, Taizhou 317500
  • Received:2018-07-05 Revised:2018-11-05 Online:2019-04-20 Published:2019-04-20

摘要: 为深入分析叶栅内压力脉动特性对流致噪声的影响,选取结构形式规则的旋涡泵叶栅,基于RNG k-ε模型模拟其内部三维非稳态流动,通过外特性试验验证数值方法的准确性后,提取叶片表面非定常压力脉动为声源,利用间接边界元法求解叶栅旋转偶极子源引起的外场噪声。结果表明:各监测点的压力脉动幅值和流量呈负相关,沿流体的运动方向压力脉动幅值和流体能量增大的方向一致,非设计流量下隔舌区域压力脉动较小。外声场表现出较强的偶极子性,设计工况下的声压级数值最小,非设计工况下声瓣以旋转轴为中心沿顺时针发生偏转,在数值上呈放射状增大趋势,且随着流量的减小偏转和放大程度依次递增。压力脉动和流致噪声的主频均为转频,压力脉动的次主频为叶频及其倍频,而声压级的次主频不显著,但从叶频处开始声压级曲线下降的趋势变慢,声压级的振荡趋于规则,从而叶栅降噪优化设计时应更加关注转频处的流致噪声。

关键词: 流致噪声, 声压级, 旋涡泵, 压力脉动, 叶栅

Abstract: To analyze the effects of the cascade pressure pulsation on the flow-induced noise, the regenerative pump was selected since its irregular cascades, the three-dimensional unsteady flow is simulated based on the RNG k-ε turbulence model. The pressure pulsation on the cascade surface is extracted as the sound source, after the accuracy of the numerical simulation method has been verified by the performance experiment. The indirect boundary element method is employed to solve the external field noise caused by the rotating dipole source. The results show that the pressure pulsation amplitude has the negative relationship with the flow rate, as well as it keeps same direction with the fluid energy increasing along the fluid movement direction, while its relative minimum appears on the position of the tongue region under non-design flow rate mode. The external sound field presents the character of strong dipole, the sound pressure level maintains it local minimum at the design operation, the sound lobes clockwise rotates as the shaft center is its rotating axis under the non-design condition, its magnitude increases in a radial manner, while the degree of the enhancement and rotation improves with the flow rate decreasing. Both the pressure pulsation and flow-induced noise main frequency are the rotation frequency, the secondary frequency of the pressure pulsation are the blade passing frequency and its harmonic frequency, while the secondary frequency of the sound is quite blurred, the sound pressure level curve decreasing tendency turn to slow, its oscillation tends to be more regularly starting at the blade passing frequency. Thus, much more attention should be paid to decrease the cascade flow-induced noise at its rotation frequency when the cascade noise reduction optimization designing.

Key words: cascade, flow-induced noise, pressure pulsation, the regenerative pump, the sound pressure level

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