关键词: 液体火箭发动机;整体叶盘;音叉式涡轮转子;振动特性;节径型振动

Abstract: A turbine rotor with tuning fork bilsk was adopted in the liquid rocket engine， there have been many cracks in the fillet of the root of the rotor disk shaft during the test run. In order to infer the causes of the crack， the structural vibration characteristics of the turbine rotor， such as the stress state， modal shape and damping ratio were analyzed through numerical calculation and modal test. Combined with the analysis of the vibration signal， the fault causes were focused on the 2 nodal diameter vibration of the blade disk. To obtain the vibration characteristics of the rotor in working condition， the pressure pulsation in the turbine flow were obtained by using high-frequency and fast-changing pressure sensors. The experimental results show that the pressure pulsation with the largest frequency division amplitude corresponds to the forward wave vibration of the rotor with the 2 nodal diameter mode， with an amplitude of about 11kPa. It was concluded that the 2 nodal diameter vibration was the main cause of the rotor failure.

Key words: Liquid rocket engine;Blisk;Tuning fork turbine rotor;Vibration characteristics;Nodal diameter vibration