水电能源科学

为了研究不同运行工况下混流泵装置内部空化流动特性，采用数值模拟的方法，基于SBES湍流模型和ZGB空化模型，分析了混流泵在不同流量工况下叶轮区内的空化气泡发展及叶轮进出口监测点处的压力脉动特性规律。结果表明，空化初期空化气泡分布在叶片背面进口处，随着空化程度加深，叶片背面进口处气泡逐渐增加，同时叶轮轮缘的下方区域出现了大量气泡，并延伸至叶片背面外缘处。叶轮进口处的压力脉动主频为叶片数通过频率，轮缘部位的压力脉动强度高于轮毂部位。空化初期叶轮出口处的主频为叶片数通过频率，随着空化的发展，在小流量和设计流量下主频转变为了转频，而在大流量下主频保持不变。

In order to investigate the cavitation flow characteristics of mixed-flow pump under different operating conditions, numerical simulations were conducted based on the SBES turbulence model and the ZGB cavitation model. The simulations analyzed the development and distribution of cavitation bubbles in the impeller region and the pressure pulsation characteristics at monitoring points in the inlet and outlet of the impeller under diverse flow rates. The results indicate that at the initial stage of cavitation, cavitation bubbles are distributed at the leading edge of blade suction surfaces. As cavitation intensifies, the area of bubbles at the leading edge gradually increases. Meanwhile, many bubbles appear in the lower region of the impeller shroud, extending to the edge of the blades' suction side. At the impeller inlet, the primary frequency of pressure pulsation is the blade passage frequency and the intensity at the impeller shroud inlet is higher than that at the hub inlet. As cavitation develops, at low flow rates and design flow rates, the dominant frequency at the impeller outlet shifts from the blade passage frequency to the rotational frequency, while at large flow rates, the dominant frequency remains the blade passage frequency unchanged.