砂粒粒径对航空涡轴发动机压气机叶片冲蚀磨损的影响研究

Influence of Sand Particle Size on the Erosive Wear of Compressor Blade in an Aero-turboshaft Engine

高原、沙漠和沿海等服役环境中不同粒径的砂粒不可避免地对涡轴发动机压气机叶片造成冲蚀磨损,破坏叶片叶型和动力学特性,严重危及涡轴发动机使用寿命和直升机飞行安全。基于Finnie冲蚀磨损理论推导了颗粒对金属表面的磨损率表达式,分析颗粒粒径对材料冲蚀磨损率的影响,以某型涡轴发动机压气机动叶和静叶为研究对象,设计搭建砂粒冲击速度测试装置和钛合金冲蚀磨损实验装置,通过典型砂粒粒径下冲蚀磨损实验获取磨损率表达式中与靶材材料和冲击速度相关的关键参数,结合气固两相流动力学分析开展砂粒粒径对压气机动叶和静叶冲蚀磨损的影响研究。结果表明:砂粒粒径与冲击速度存在内在关联,材料冲蚀磨损率与砂粒冲击速度呈幂函数关系。实验条件下,砂粒粒径由177μm增至423μm时,其冲击速度平均降低约17%。压气机动叶和静叶的磨损集中区域不随砂粒粒径的改变而变化,但磨损程度差异明显,其中177μm砂粒对动叶和静叶造成的最大冲蚀磨损率浓度值相比423μm砂粒分别增加91%和131%。研究结果为涡轴发动机压气机叶片抗磨损设计提供了理论参考。

Sand particles of different sizes inevitably cause erosive wear on the compressor blades of turboshaft engine in service environments such as plateaus,deserts and coastal areas,which can damage the profile and dynamic characteristics of the blades,and seriously affect the service life of turboshaft engines and the flight safety of helicopters.Based on the Finnie erosive wear theory,the expression showing the wear rate on the metal surface caused by particles is derived,and the influence of the particle size on the wear rate of materials is analysed.With the compressor rotor blade and stator blade of a certain type of turboshaft engine as the research objects,a sand particles impact velocity test bench and a Ti-6Al-4V alloy erosive wear test bench are designed and built.The key parameters which are related to the target material and impact velocity in the expression of wear rate are obtained through the erosive wear experiments under the typical sand particle size.The effects of sand particle size on the erosive wear of compressor rotor blades and stator blades are carried out combined with the gas-solid flow dynamic analysis.The results show that there is an internal relationship between the sand particle size and impact velocity and that a power function relationship exists between the erosive wear rate of materials and the impact velocity of sand particles.Under the experimental condition,when the particle size increases from 177μm to 423μm,its impact velocity is reduced by about 17%on average.The wear concentration areas of the compressor rotor blade and stator blade do not change with the sand particle size,but the difference in the wear degree is obvious.Among them,the maximum concentration values of the wear rate caused by 177μm sand particles on the rotor blade and stator blade increase by 91%and 131%,respectively,compared with those caused by 423μm sand particles.In conclusion,the above results can provide theoretical reference for anti-wear design of the compressor blades of turboshaft engine.