基于流固耦合的隔舌位置对双流道泵综合性能的影响

为了研究隔舌位置对双流道泵水力性能与结构性能的影响,针对3种不同隔舌安放角的双流道泵进行双向流固耦合计算,结果表明:水力性能方面,隔舌位置对扬程的影响较小,而对效率的影响较大,3种方案的最大扬程差仅为0.09 m,而最大效率差达1.1%;隔舌位置主要影响隔舌圆角及往第1断面方向附近与叶轮间隙处的压力脉动程度,隔舌安放角越大,压力脉动越强;叶轮旋转1周,蜗壳所受径向力呈现周期性变化规律,叶片扫过隔舌圆角时,蜗壳所受径向力最小,转过90°时径向力达到最大值.增大隔舌安放角可显著减小蜗壳所受径向力.结构性能方面,叶轮应力集中出现在出口吸力面,蜗壳应力集中出现在隔舌圆角附近靠后盖板处,增大隔舌安放角会增加蜗壳的最大应力值,但振幅减小;双流道泵发生10^-5m量级的位移,最大位移出现在蜗壳出口处,主要受叶片通过频率的影响,呈周期变化趋势,且随着隔舌安放角的增大,蜗壳最大变形量增大,振幅减小;隔舌位置对泵的振动速度影响比较明显,增大隔舌安放角,有助于减小振动.

Impact of tongue angles on hydraulic and structural performance of double-channel pump based on fluid-structure interaction

In order to study the influence of tongue angles on hydraulic and structural performances of double channel pump, three cases with different tongue angles were simulated by the two-way coupling fluid-structure interaction(FSI)method. The result shows that in the hydraulic performance aspect, the influence of tongue angles on flow-head is weak, and the maximum difference is 0.09 m,but the maximum difference of efficiency is 1.1%. Tongue angle mainly affects the pressure fluctuation in and after the tongue edge,and the larger the tongue angle is,the stronger the fluctuation is.Because of the asymmetry of the volute, radial force on the volute is very large.It is periodical when the impeller rotates one circle and decreases obviously with the increasing of the tongue angle. In the structural performance aspect,stress concentration of the impeller appears in the suction surface near the outlet,and the volute stress concentration appears near the tongue edge.The increasing of tongue angle will increase the value of the maximum stress of the impeller and volute,but the amplitude will decrease. Displacement with the magnitude 10^-5 m happens in the pump, and the maximum displacement appears at the outlet of the volute. It is periodical and is mainly influenced by the blade-passing frequency. The tongue angle has little impact on the maximum displacement,but has an obvious effect on the vibration velocity of the pump.Larger tongue angle can suppress the vibration.