This paper gives the flow simulation of hydraulic turbinedraft tubes. Then, the calculation formula of the frequency and force of vibration of the draft tube are derived.
本文通过尾水管内流动的模拟，导出了由尾水涡带所引起的周期性振动的振动频率和脉动压力的计算公式。
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The unsteady flow in a drafttube of Francis turbine under the off-design operation is produced by the dynamic behavior of a helical vortex rope with the dead core.
To diagnose accurately vortex rope in drafttube of hydraulic turbine, this paper presents a new method of fault diagnosis based on wavelet packet and neural network.