舰船低噪声离心泵设计与验证

Design and Validation of Low-Noise Centrifugal Pumps Utilized in Ships

  • 摘要: 【目的】旨在解决舰船离心泵的叶频线谱激励突出问题。【方法】以某舰船所用相同类型的离心泵为对象,采用数值仿真和试验测试的方法对泵内部流动及激励特性进行了研究,对常规叶轮进行优化,提出基于分流叶片的复合叶轮设计思想。通过对比分析优化前后的定常流场和非定常性能,揭示了优化机理,并对优化效果进行了试验验证。【结果】结果表明,复合叶轮能够降低长叶片的叶片载荷,提高叶轮出流的均匀性,复合叶轮模型的叶轮出口相对速度的标准差与常规叶轮相比减小了5.9%,较常规分流叶片叶轮减小了1.67%;复合叶轮能够有效降低泵内非稳态流动产生的整体脉动强度,叶轮出口的压力脉动和径向力脉动显著下降,叶轮出口周向平均整体压力脉动幅值相较于常规模型下降47.8%,较常规分流叶片下降了21.7%;叶频激励力由常规叶轮的0.42N下降至0.04N。复合叶轮设计思想具有显著抑制泵内叶频线谱激励的工程价值,试验表明,复合叶轮模型较常规叶轮模型泵的机脚振动叶频强度下降了92.4%,相较于传统分流叶片设计下降了53.9%;与常规叶轮相比在额定工况点的低频总振动级降低了3.25dB,较常规分流叶片叶轮下降了0.97dB。【结论】基于分流叶片的复合叶轮设计思想能够在常规分流叶片的基础上进一步降低离心泵的流体激励,所做研究为低振动低噪声离心泵设计提供了参考。

     

    Abstract: Objectives This paper aims to address the prominent issue of blade pass frequency excitation in centrifugal pumps used utilized in Ships. Methods A centrifugal pump of the same type utilized in ship is selected as the research object. A combination of numerical simulation and experimental testing is employed to investigate the internal flow and excitation in the pump. The original impeller is optimized, and a novel design concept of a composite impeller based on splitter blades is proposed. By comparing the steady flow field and unsteady performance before and after optimization, the underlying optimization mechanism is revealed, and the optimization effect is experimentally validated. Results The results show that the composite impeller can reduce the blade load on long blades and improve the uniformity of the outlet of the impeller. The standard deviation of the relative velocity at the impeller outlet of the composite impeller model is reduced by 5.9% compared to the conventional impeller, and by 1.67% compared to the conventional splitter blade impeller. Additionally, the composite impeller effectively mitigates the overall pulsation intensity caused by unsteady flow within the pump. Notably, pressure pulsations and radial force fluctuations at the outlet of impeller are significantly reduced. Specifically, the circumferential average amplitude of overall pressure pulsations at the outlet of impeller decreased by 47.8% compared to the conventional model, and decreased by 21.7% compared to the conventional splitter blade. Moreover, the blade frequency excitation force is reduced from 0.42 N to 0.04 N compared to the conventional model. The composite impeller demonstrates significant potential for suppressing blade frequency excitation, offering engineering value, experimental results indicate that the vibration intensity at the machine feet of the composite impeller model decreased by 92.4% compared to the conventional impeller model and decreased by 53.9% compared to the conventional splitter blade. Besides, the total vibration level in the low-frequency band is reduced by 3.25 dB compared to the conventional model and 0.97dB compared to the conventional splitter blade. Conclusions The design concept of a composite impeller based on splitter blades can further reduce the fluid-induced excitation in centrifugal pumps compared to conventional splitter blades. This research provides valuable references for the design of low-vibration and low-noise centrifugal pumps.

     

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