导叶周向布置位置对核主泵压力脉动的影响

基于RNG k-ε湍流模型和滑移网格模型,对核主泵导叶在不同周向位置缩比模型的内部流动进行全三维非定常数值计算。研究导叶周向布置位置对叶轮出口、叶轮-导叶间隙处以及泵壳内压力脉动的影响规律,并分析导叶周向位置对导叶下游流动的影响,结果表明:导叶周向位置对模型泵内压力分布影响较大,在时域图中,导叶位置主要影响模型泵内压力脉动的波动幅度,导叶在α=0?时压力脉动的主波动幅度最小;在频域图中,导叶位置主要影响压力脉动能量幅值,导叶在α=0?时脉动能量幅值最小。叶轮出口的压力脉动能量幅值最大,泵壳内的能量幅值最小,压力脉动主要由动、静叶间的相互干涉引起。叶轮出口、叶轮-导叶间隙处的压力脉动频率主要受叶频影响,泵壳内的压力脉动频率仅与转频有关。导叶周向位置对导叶下游的内部流动影响较大,导叶在α=0?时截面B—B内的压力分布均匀、压力梯度小。合适的导叶周向位置可有效改善泵内的压力脉动分布,进而降低泵的振动。

Influence of Circumferential Position of Guide Vane on Unsteady Flow Characteristics in Reactor Coolant Pump

Based on RNGk-ε turbulence model and sliding mesh model, a three-dimensional unsteady numerical calculation is carried out for reduced-scale models of reactor coolant pump whose guide vane is located in different circumferential positions. The influence law of circumferential position of guide vane on the pressure fluctuations at the impeller outlet, the gap of impeller and guide vane and pump casing is studied, and influence of circumferential position of guide vane on the downstream flow of guide vane is analyzed. The results indicated that the circumferential position of guide vane had great influence on pressure distribution of model pump. The circumferential position of guide vane mainly influenced the fluctuation range of pressure fluctuation in the time domain graph and the main fluctuation range of pressure fluctuation atα=0? is the lowest; the circumferential position of guide vane mainly affected the energy amplitude of pressure fluctuation in the frequency domain graph and the energy amplitude of pressure fluctuation atα=0? is the lowest. The energy amplitude of pressure fluctuation is the highest at the impeller outlet, but the energy amplitude is the lowest at the pump casing, and pressure fluctuation is mainly caused by the rotor-stator interaction. The frequency of pressure fluctuation is mainly affected by the blade passing frequency at the impeller outlet and the gap/clearance of impeller and guide vane and is only related to the rotational speed frequency at the pump casing. The circumferential position of guide vane had more influence on the downstream internal flow of guide vane, and the pressure distribution and pressure gradient of section 1 atα=0? is more uniform and smaller. The suitable circumferential position of guide vane can effectively improve the distribution of pressure fluctuation in the pump, and then reduce the vibration of the pump.