Numerical and Experimental Investigation on Radiated Noise Characteristics of the Multistage Centrifugal Pump
Numerical and Experimental Investigation on Radiated Noise Characteristics of the Multistage Centrifugal Pump
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DOI：
10.3390/pr7110793
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发表时间：
2019-11
期刊：
影响因子：
3.5
通讯作者：
Q. Si;Biaobiao Wang;Jianping Yuan;K. Huang;Gang Lin;Chuan Wang
中科院分区：
文献类型：
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作者：
Q. Si;Biaobiao Wang;Jianping Yuan;K. Huang;Gang Lin;Chuan Wang
离心泵的辐射噪声在许多应用中作为干扰。辐射噪声与水力设计密切相关。多级泵内部水力参数复杂，各级之间的流动相互作用很强，在强烈的水力激励下，会产生振动和噪声问题。因此，必须对辐射噪声的机理及其与水力学的关系进行研究。为了研究不同工况下辐射噪声的变化规律，基于Lighthill声学类比理论，将计算过程分为计算流体动力学（CFD）和计算声学（CA）两部分，提出了一种混合数值方法求解流致噪声源。采用商用CFD软件对非定常流场进行了分离涡模拟。提取叶片扩压器表面附近的详细流动信息和计算出的流激噪声源作为水力激振力，两者均作为辐射噪声仿真的声源。声学仿真采用有限元法程序，得到声压级、频率响应、指向性等结果。实验是在半消声室内用封闭式水泵试验台进行的。对多级泵在不同流量下的泵性能和声学参数进行了测试，验证了数值计算方法的正确性。计算和实验结果都表明，辐射噪声具有典型的偶极子特性，其方向性随流量的变化而变化。此外，辐射噪声的声压级（SPL）随着流量的增加而波动，并且在0.8Qd处产生最低SPL，这对应于最大效率工况。此外，实验还发现多级泵的辐射噪声声压级随转速的增加而线性上升。最后，在此基础上进行了低噪声泵的设计实例。
The radiated noise of the centrifugal pump acts as a disturbance in many applications. The radiated noise is closely related to the hydraulic design. The hydraulic parameters in the multistage pump are complex and the flow interaction among different stages is very strong, which in turn causes vibration and noise problems because of the strong hydraulic excitation. Hence, the mechanism of radiated noise and its relationship with hydraulics must be studied clearly. In order to find the regular pattern of the radiated noise at different operational conditions, a hybrid numerical method was proposed to obtain the flow-induced noise source based on Lighthill acoustic analogy theory, which divided the computational process into two parts: computational fluid dynamics (CFD) and computational acoustics (CA). The unsteady flow field was solved by detached eddy simulation using the commercial CFD code. The detailed flow information near the surface of the vane diffusers and the calculated flow-induced noise source was extracted as the hydraulic exciting force, both of which were used as acoustic sources for radiated noise simulation. The acoustic simulation employed the finite element method code to get the sound pressure level (SPL), frequency response, directivity, et al. results. The experiment was performed inside a semi-anechoic room with a closed type pump test rig. The pump performance and acoustic parameters of the multistage pump at different flow rates were gathered to verify the numerical methods. The computational and experimental results both reveal that the radiated noise exhibits a typical dipole characteristic behavior and its directivity varies with the flowrate. In addition, the sound pressure level (SPL) of the radiated noise fluctuates with the increment of the flow rate and the lowest SPL is generated at 0.8Qd, which corresponds to the maximum efficiency working conditions. Furthermore, the experiment detects that the sound pressure level of the radiated noise in the multistage pump rises linearly with the increase of the rotational speed. Finally, an example of a low noise pump design is processed based on the obtained noise characteristics.