航空发动机燃气涡轮叶片断裂分析

Fracture Analysis of Gas Turbine Blade in Aircraft Engine

航空涡轮轴发动机的燃气涡轮叶片在工作中需要承受严酷的负荷,其工作可靠性直接影响飞行安全。针对燃气涡轮叶片断裂故障,通过开展故障件失效分析、发动机参数判读、测试数据复查复测以及发动机整机串装对比试车,确定故障肇事零组件。结合开展的燃烧室性能仿真计算结果和燃烧室部件性能试验测试结论,相互印证进一步确认故障失效模式。结果表明:涡轮叶片发生断裂的原因主要是火焰筒外壁的旋流槽尺寸超差导致燃烧室出口温度场不均匀,径向温度分布系数RTDF较大,使得高温区向燃气涡轮叶片高应力区偏移,导致叶片在偏离设计状态下工作提前失效。采取的旋流槽尺寸100%复验和增加燃气涡轮出口温度限制等措施,有效降低发动机的制造分散度,提高发动机热端部件的工作可靠性。

The gas turbine blades of aero-turboshaft engine need to withstand severe loads during operation,and its working reliability directly affects flight safety.Aiming at the fracture fault of the gas turbine blade of turboshaft engine,the fault causing components are determined through failure analysis of the fault components,engine parameter interpretation,retesting of test data and comparative testing of the entire engine in series.Combined with the combustion chamber performance simulation calculation results and the combustion chamber component performance test results,the fault failure mode is further confirmed.The main reason is the oversize of the swirl groove on the outer wall of the flame barrel,which results in the uneven temperature field at the outlet of the combustion chamber.The radial temperature distribution coefficient RTDF causes the high-temperature zone to shift towards the high stress zone of the gas turbine blades,which leads the blades deviation from design stste and early failure.The measures such as 100%reinspection of the swirl groove size and increasing the temperature limit at the outlet of the gas turbine have effectively reduced the manufacturing dispersion of the engine and improved the working reliability of the hot end components of an engine.