混流式水轮机尾水管不稳定周期性水流的相似律

本文作者提出了用以研究混流式水轮机尾水管中不稳定周期性水流的相似律。给出由尾水管中水流环量引起的低频压力脉动频率与振幅的计算表达式。某些水电厂试验表明,计算表达式是正确的。提出在大型混流式水轮机转轮出口处装设轴流式诱导轮,做为消除由尾水管低频压力脉动引起的水轮机振动的措施。

Similarity Laws of Periodically Unsteady-flow Through Draft Tube of Mixed-flow Water Turbine

In this paper the author presents the similarity laws used to study periodically unsteady-flow in draft tube of mixed-flow water turbine and gives a calculation expression with which the frequency and amplitude of a low-frequency pressure pulsation arising from the circulation of the flow through the draft tube can be calculated. Experiments in some water power plants have proved that the calcu- lation expression is available. The author also proposes that an axial-flow guide runner be installed near the outlet of runner of large mixed-flow water turbine as a measure to remove the turbine's vibration arising from the low-frequency pressure pulsation in draft tube.