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核主泵内的流动不稳定将会引起严重振动,不利于其安全稳定运行。因此本文基于大涡模拟(LES)数值计算方法对几个典型工况下核主泵内部非稳态流动结构及其压力脉动特性进行全面阐述与关联性分析。研究表明,随着流量的增加,动静干涉作用在导叶出口处逐渐增加;偏工况条件下,导叶出口处压力脉动频谱低频段中均出现复杂激励频率,尤其是靠近出液管附近的导叶出口处。核主泵在偏大流量工况下运行时壳体右侧内部非稳态流动结构相较于壳体左侧更加复杂;在偏小流量工况下运行时壳体底部压力脉动更加剧烈。本文进一步详细描述了核主泵球形壳体内强涡量区的流动结构及其成因,并且发现测点处的压力频谱与涡量频谱有相同的主要激励频率,因此证明核主泵内非定常旋涡流动结构是激励压力脉动的主因之一。
Nuclear instability in the main pump will cause serious vibration, is not conducive to its safe and stable operation. Therefore, based on large eddy simulation (LES) numerical calculation method, the unsteady flow structure and pressure pulsation characteristics of nuclear main pump under several typical operating conditions are fully expatiated and analyzed. The results show that with the increase of flow rate, the static and dynamic interference increases gradually at the exit of the guide vane. Under the conditions of partial working conditions, the complex excitation frequency appears in the low frequency band of the pressure pulsation at the exit of the guide vane, especially near the exit Vane exit. When the nuclear main pump is operated under the conditions of large flow, the internal unsteady flow structure on the right side of the shell is more complicated than that on the left side of the shell. The pressure pulsation at the bottom of the shell is more severe under the condition of low flow rate. In this paper, the flow structure and its cause of the strong vorticity region in the spherical shell of the main pump are described in detail, and it is found that the pressure spectrum at the measuring point has the same main excitation frequency as the vorticity spectrum. Therefore, it is proved that the unsteady vortex Flow structure is one of the main causes of pressure pulsation.