热斑效应下航空发动机热障涂层涡轮叶片CMAS沉积规律的实验研究

航空发动机燃烧室出口温度场普遍分布不均，热斑加剧了透平内部非定常流动和传热的复杂性，影响颗粒在叶栅内的扩散与沉积过程，导致发动机性能恶化及可靠性损伤。本申请项目通过平板状TBCs试样表面的CMAS颗粒高温沉积实验，确立影响沉积的主要因素及其对沉积速度、沉积形态等的影响规律；综合考虑粒子粘度与速度值对沉积的影响，建立CMAS颗粒沉积的理论模型，通过实验修正理论模型；基于CMAS高温腐蚀实验模拟装置，结合UDF模块编制粒子的沉积模型，对实际涡轮叶片热障涂层的CMAS颗粒沉积过程进行实验研究与数值计算，分析叶片几何形状改变以及气膜冷却存在时，相关参数对CMAS颗粒沉积行为影响机制的改变；改造CMAS高温腐蚀实验模拟装置，设计新型的热斑模拟器，实现热斑特性参数的精确加载，开展热斑作用下叶片表面的CMAS颗粒沉积实验，提炼出CMAS颗粒高温沉积的关键影响因素，为热障涂层及气膜冷却优化设计提供指导。

The gas flow temperature distribution are usually seriously non-uniform at the exit of aero engine combustor. Migration of hot streak intensifies the complexity of the unsteady flow and heat transfer in turbine stage, and thus effect the diffusion and deposition process of CMAS particle in turbine stage which may leads to the deterioration of gas turbine performance and reliability. The main factors and their influence on deposition rate and deposit form will also be studied through the experiment of CMAS particle deposition on plane plate with thermal barrier coatings. With consideration the effects of the viscosity and velocity of particle, a newly particle deposition model will be established and verified with experimental data. Experimental study and numerical calculation of the CMAS particle deposition behavior on the thermal barrier coatings of the actual turbine blades will be carried out with the experiment on high temperature corrosion test rig and UDF module in Fluent code. The influence of relevant parameters on the deposition behavior of CMAS particles will be analyzed when the geometrical shape of the blade is changed and the gas film cooling existed. Furthermore, A newly hot streak simulation device will be developed and mounted on the high temperature corrosion test rig to accurately simulate flow temperature distribution. The influence of the characteristic parameters of hot streak on the deposition process of the static blade surface will be studied experimentally. The key influencing factors on deposition process of CMAS particle will be extracted, which could provided guidance for the optimization design of thermal barrier coating and film cooling.