【摘要】 本文对某电站原型混流式水轮机进行三维非定常多相湍流模拟,对大轴中心孔补气前后水轮机各过流部件内的压力脉动进行计算,并与试验结果相比较,探讨了水轮机补气减振的机理。分析结果表明:大轴补气能够减小尾水管断面的压差,从而降低尾水管低频压力脉动的振幅,但对振动频率影响不明显;补气孔入口与转轮之间存在动静干扰,在转轮区域形成新的振源,增强了转轮前的中频压力脉动。更多还原

【Abstract】 In this paper,the three-dimensional unsteady multiphase flow is simulated in the whole passage of Francis hydraulic turbine.The pressure pulsation is calculated and compared with the experimental data at positions in the draft tube,in front of runner,guide vanes and in the inlet of the spiral case.The relationship between pressure pulsation in the whole passage and air admission is analyzed. The computational results show that air admission from spindle hole decreases the pressure difference in the horizontal section of draft tube,which decreases the amplitude of low-frequency pressure pulsation in the draft tube;the interaction between the air inlet and the runner increases the middle-frequency pressure pulsation in front of the runner.更多还原