液体火箭发动机音叉式涡轮叶盘振动特性研究

Vibration Characteristics of Tuning Fork Turbine Blisk of Liquid Rocket Engine

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

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

摘要:

某液体火箭发动机整体叶盘音叉式涡轮转子的盘-轴根部圆角在试车考核中曾多次出现裂纹故障。为分析裂纹产生原因，通过数值计算及模态实验获取了该转子受力状态、振型、阻尼比等结构振动特性。结合振动信号分析，将裂纹故障原因聚焦到叶盘的二节径型振动。通过高频速变压力测量，得到涡轮流场内压力脉动数据，间接获取了该转子工作状态下的振动特性。试验表明被测涡轮转子流场通道内，分频幅值最大压力脉动对应涡轮转子2节径前行波振动，幅值约为11kPa。分析确定涡轮叶盘二节径振动是故障产生的主要原因。

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.