以轴流式水轮机全流道三维非定常湍流数值模拟为基础,对轴流式水轮机尾水管内的非定常流场进行了分析,研究了尾水管内涡带的形态,对尾水管压力脉动的幅值和频率特点进行了分析。结果表明,大流量工况时,在尾水管内形成了一个与转轮旋转方向相反低压涡带,引发了低频压力脉动,这种低频压力脉动是水轮机中压力脉动的主要脉动源之一。 Based on the numerical simulation of three-dimensional unsteady turbulent flow in a full runner of an axial-flow turbine, the unsteady flow field in the draft tube of an axial-flow turbine is analyzed and the shape of the vortex in the draft tube is studied. Amplitude and frequency characteristics were analyzed. The results show that at high flow rate, a low pressure vortex is formed in the draft tube opposite to the rotating direction of the rotating wheel, which causes low frequency pressure pulsation, which is one of the main pulsating sources of pressure pulsation in hydraulic turbine.