The internal flow of the mini pumps for washing machines is complex due to its compact structure and it normally adopts the upper drainage method. Due to decline in liquid level at the end of drainage (empty discharge period), the pump experiences water–air multiphase flow condition and produces unsteady flow. This unstable flow not only results in the deterioration of pump energy performance, but also induces larger vibration and noise, which in turn, reduce the working capability of pumps and disturb the people living environment. Therefore, with the aim of exploring the internal flow features and noise characteristics of drainage pumps during empty discharge period, the energy performance test was processed under pure water condition as well as under different air void fraction and part load conditions. Moreover, the internal flow field is calculated based on (both k − ε and k − ω) turbulence model and Euler non-uniform stream model under pure water, and different inlet air content for part load conditions, respectively. All the experimental conditions for test and boundary conditions for simulation are provided. The overall and local results of internal flow field and gas phase distribution are obtained and analyzed. In addition, the research results can provide a theoretical recommendation for designing the lower noise mini pumps.

洗衣机用微型水泵结构紧凑，内部流量复杂，一般采用上排水方式。由于排液末（空排期）液位下降，泵出现水气多相流状态，产生非定常流动。这种不稳定的流量不仅会导致泵的能量性能变差，还会引起较大的振动和噪声，从而降低泵的工作能力，干扰人们的生活环境。为此，为探究排空期排水泵内部流动特征和噪声特性，在纯水工况、不同含气率和部分负荷工况下进行了能效试验。而且，k − ε和k − ω ) 湍流模型和欧拉非均匀流模型分别在纯水和部分载荷条件下不同入口空气含量下。提供了用于测试的所有实验条件和用于模拟的边界条件。获得并分析了内部流场和气相分布的整体和局部结果。此外，研究结果可为设计低噪声微型泵提供理论建议。