両吸込遠心ポンプに発生するキャビテーションがトルクと圧力損失に及ぼす影響

抄録

The present research investigated flow characteristics in a square-root-shaped region of a suction performance curve based on computational fluid dynamics (CFD). The square-root-shaped region observed in the experiment was well simulated by CFD. Cavitation surge and rotating cavitation occurred in the square-root-shaped region. The square-root-shaped region was observed only in the suction performance curve of the computational domain of the impeller. The square-root-shaped region is caused by the changes of the torque and the pressure loss due to cavitation. The torque fluctuation had the opposite phase to the cavity volume fluctuation. On the other hand, the pressure loss had the same phase as the cavity volume fluctuation. The vorticity was generated from the cavity and the generated vorticity led to the decrease of the torque and the increase of the pressure loss. The blockage of the blade passage due to cavitation decreased the torque and increased the pressure loss and vorticity.