涡轮叶片热障涂层隔热性能和应力数值模拟

Numerical Simulation of Thermal Insulation Performance and Stress of Thermal Barrier Coatings on Turbine Blades

提高涡轮发动机进口温度是提升航空发动机推重比和热效率的主要手段,但当今先进航空发动机的进口温度已经远远超过了现有涡轮叶片材料的极限温度,发展冷却技术和热障涂层技术成为解决这一问题的关键.在热失配应力下热障涂层界面易出现裂纹的萌生和扩展,会直接导致热障涂层的失效,进而威胁到整个发动机的性能,因此,模拟热障涂层真实服役环境下的温度场和应力场分布,对于预测热障涂层的隔热效率和剥落位置极其重要.该文基于流固耦合的方法,运用商业软件ANASYS CFX模拟了带TBCs的三维涡轮叶片的温度场,并进一步计算了热障涂层的热应力.结果发现热障涂层在叶片前缘和压力面区域有更好的隔热性能,热障涂层在叶根和气膜孔处有更大的应力,是热障涂层剥落的危险区域.

Increasing the inlet temperature of turbine engine is the main technical means to improve the thrust and thermal efficiency of aeroengine.Nowadays,the inlet temperature of advanced aero engines has far exceeded the limit temperature of existing materials used by turbine blade.Therefore,the development of thermal barrier coatings has become the key to solve this problem.However,the crack expands and spalling failure in thermal barrier coatings will directly lead to failure of turbine blade and threaten the service of the whole engine.Therefore,it is very important to simulate the temperature field and stress field distribution of thermal barrier coating under the real service environment to predict the thermal insulation efficiency and the peeling location of thermal barrier coating.In the work,based on the method of fluid-solid coupling,the temperature field of the three-dimensional turbine blade with thermal barrier coatings were simulated by the commercial software ANASYS CFX,furtherly,the thermal stress of the thermal barrier coating was calculated.The results showed that the thermal barrier coating had better thermal insulation performance on the region of the leading edge and pressure surface of the blade,and the stress of the thermal barrier coating was greater on the region of film hole and the root of blade and,where was a dangerous area for the thermal barrier coating to peeling.