【摘要】 以轴流式水轮机全流道三维非定常湍流数值计算结果为基础,采用弹性力学非稳态有限元法开展了轴流式叶片的动应力问题研究。计算结果表明,水轮机内部随时间变化的压力场导致叶片结构承受了较大的动态应力,叶片上的最大等效应力点与实际叶片破坏的位置一致;各工况相比叶片转角越小,叶片应力波动越剧烈;叶片上各点的动应力频率成分与流道内的水压力脉动频率基本一致,叶片上的高幅动应力是引起叶片裂纹,导致结构破坏的主要原因。更多还原

【Abstract】 Based on 3-D unsteady turbulent numerical simulation results of three dimentional passage in axial hydroturbine,dynamic stress analysis of the axial turbine blade is carried on by using the elasticity unsteady FEM. The results show that the pressure field changing with time in the turbine causes the large dynamic stress in the blade. The maximum stress points is consistent with the damaged position in the real blade. The less the blade angle is,the larger the stress fluctuates. The frequency components of the dynamic stress in blade are consistent with the frequency components of water pressure in the flow channel. The high-amplitude dynamic stress in the blade is the main cause of blade crack,it leads to structure damage.更多还原