燃气轮机叶片含孔热障涂层中TGO热生长及其对涂层多层结构应力演化影响的研究

With an increasing demand for the sustainable operation of thermal barrier coatings (TBCs) in advanced gas turbine, the objective of the present study is to perform fundamental study in the fluid-structure coupling heat transfer, thermo-mechanical behavior and experimental validation of multilayer structure for TBCs with cooling hole, due to the mutual influence between TGO growth and stress evolution in multilayer structure of TBCs. The following issues will be addressed in this project: (1) Development of the fluid-structure coupling heat transfer model with the influence by pores in TBCs, the research results will be able to accurately predict the temperature distribution within TBCs near the hole; (2) three-dimensional (3D) growth behavior modeling of TGO under the combined effects of temperature gradient and constraint of the cooling hole on the basis of experimental measurement and validation. The effect of temperature gradient and constraint of the cooling hole on the TGO growth in 3D space will be clarified; (3) For a system of film cooling – TBCs of gas turbine blade, 3D numerical model of thermo-mechanical behavior in multilayer structure of TBCs is established to elucidate the thermal mismatch behavior in TBCs. The present project is an interdisciplinary topic, which will include the mechanical, mechanics, and material analysis research fields. The research results will be significantly important to the gas turbine community, since it could offer meaningful insight to the TGO growth behavior in 3D space under the combined effects of thermal gradient and constraint of cooling hole, and the influence of this growth on stress evolution in multilayer structure of TBCs. The 3D modeling of TGO growth behavior for engineering application can be developed. Also, this project could provide some important insight into the development of long-life design of hot sections and manufacturing of TBCs with cooling holes in gas turbines.

面向先进燃气轮机叶片热障涂层结构可靠性的需求，针对含孔(带冷却孔)热障涂层中高温氧化物(TGO)热生长和多层结构应力演化的相互影响，系统开展含孔热障涂层流固耦合传热数值模拟、多层结构热力行为建模分析及实验验证研究。主要包括：1)建立微小空隙结构影响下含孔热障涂层的流固耦合传热数值模型，实现冷却孔附近涂层温度分布的准确预测；2)通过复杂热力环境下含孔热障涂层实验测量和验证，建立温度梯度和孔口拘束下的三维空间TGO热生长模型，澄清温度梯度和孔口拘束对TGO在三维空间上热生长的影响；3)针对燃气轮机叶片气膜冷却—热障涂层系统，建立涂层多层结构全三维热力行为数值模型，揭示流固耦合传热下含孔热障涂层结构热失配行为。本项目体现了机械、力学和材料等多学科交叉，阐明冷却孔附近三维空间TGO热生长及其对涂层多层结构应力演化影响的规律并建立数值模型，为燃气轮机高温含孔热障涂层结构设计以及寿命预测提供科学支持。

叶片热障涂层的结构完整性是影响叶片服役寿命的重要因素之一。本课题面向先进燃气轮机叶片热障涂层结构可靠性的需求，针对带冷却孔热障涂层中TGO热生长和多层结构应力演化的相互影响，系统开展了含孔热障涂层流固耦合传热数值模拟、多层结构热力行为建模分析及实验验证研究。. 本课题首先研究了空隙结构影响下含孔热障涂层的流固耦合传热规律，实现了冷却孔附近涂层温度分布的准确预测，并进行了相关定量分析。其次开展了复杂热力环境下含孔热障涂层实验测量和验证，建立温度梯度和孔口拘束下的三维空间TGO热生长模型，澄清了温度梯度和孔口拘束对TGO在三维空间上热生长的影响；最终，针对燃气轮机叶片气膜冷却—热障涂层系统，建立涂层多层结构全三维热力行为数值模型，揭示了流固耦合传热下含孔热障涂层结构热失配行为。. 本课题集成了机械、力学和材料等多学科交叉，阐明了冷却孔附近三维空间TGO热生长及其对涂层多层结构应力演化影响的规律并建立相关数值模型，为燃气轮机高温含孔热障涂层结构设计以及寿命预测提供科学支持。