Analysis of the cause of the 40Hz frequency component in spiral casing of a high-head pump turbine

Vibration and noise problems affect the safe and stable operation of pump turbines. For the design of pump turbines, it is crucial to accurately identify the excitation sources and their evolution laws that cause vibration and noise. Based on numerical calculation methods, this paper studies the 40Hz frequency component that occurs in the spiral case of a prototype pump turbine during operation in a power plant. Upon analysis of the internal flow characteristics of the spiral case, the study examines the causes for the formation of pressure pulsations at this frequency component and their transmission laws.