Intense fluid-dynamic interaction at the impeller outlet strongly affects the unsteady flow and pressure stability within the centrifugal pump. In order to have a better understanding of the pressure fluctuation of centrifugal pumps, a numerical calculation is carried out by using the RNG k-epsilon turbulence model under various flow rates. The numerical calculation results are compared with the experimental results in order to verify the reliability of the calculation model. The amplitude and frequency distribution of pressure fluctuation at the impeller outlet is obtained and analyzed in the time and frequency domain. The research results show that the blade passing frequency is the dominant frequency of the pressure fluctuation. And the pressure fluctuation is a periodic fluctuation. As the flow rate decreases, the periodicity of the pressure fluctuation decreases. Besides, the amplitude and intensity of pressure fluctuation are closely related to flow rate and spatial location. At the low flow rate, the amplitude of pressure fluctuation in the time domain and frequency domain is enlarged greatly, especially near the tongue region. The pressure difference distribution on both sides of the blade surface is extremely uneven, and the pressure changes significantly.

中文翻译：

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离心泵叶轮出口压力非定常波动的数值研究

叶轮出口处强烈的流体动力学相互作用强烈影响离心泵内的非定常流动和压力稳定性。为了更好地了解离心泵的压力波动，利用RNG k-epsilon湍流模型在不同流量下进行数值计算。将数值计算结果与实验结果进行对比，以验证计算模型的可靠性。得到叶轮出口压力波动幅度和频率分布，并在时域和频域进行分析。研究结果表明，叶片通过频率是压力波动的主导频率。并且压力波动是周期性波动。随着流量的减少，压力波动的周期性减小。此外，压力波动的幅度和强度与流量和空间位置密切相关。在低流速下，压力波动在时域和频域的幅值都有很大的扩大，尤其是在舌区附近。叶片表面两侧压力差分布极不均匀，压力变化明显。