中文摘要：

为研究核主泵内部流场压力脉动情况，采用大涡模拟方法对模型泵内部流场进行了三维非定常数值模拟，通过设置监测点，得到了不同位置处的压力脉动结果，并进行了频域分析．结果表明：核主泵模型泵内最大压力脉动发生在叶轮出口处，从叶轮进口到导叶出口，压力脉动先增大后减小，压力脉动频率主要受叶轮转频控制；在球壳内部压力脉动沿着球壳半径方向逐渐减小，且压力脉动频率与叶轮转频有关．

英文摘要：

In order to study internal pressure fluctuations of main coolant pump, the large eddy simulation method was applied to simulate the 3-D unsteady flow in the model pump. The pressure fluctuations at different locations were obtained by setting monitoring points, and frequency domain analysis was achieved. Results show that the maximum amplitude of pressure fluctuation takes place at the outlet of impeller. From the inlet of impeller to the outlet of guide vanes, the fluctuation amplitude increases at first and then decreases, the frequency of pressure fluctuation is dominated by rotational frequency of the impeller. The fluctuation amplitude in the spherical shell decreases along the radial direction, and the frequency of pressure fluctuation is related to rotational frequency of the impeller.