考虑槽缝和气膜孔射流冷气掺混的高负荷透平静叶非轴对称端壁气热性能和流热耦合机理研究

The aerothermal performance and flow/heat transfer coupling mechanisms of the non-axisymmetric endwall high-loaded turbine vane considering the mixing of the upstream slot and film cooling hole injection is to be experimentally measured and numerically analyzed in details. The aerothermal performance parameters and flow field visualization experimental system of non-axisymmetric endwall turbine vane is to be established under the effect of the upstream slot and film cooling hole injection. The effect of the upstream slot structure and endwall film cooling hole layout on the secondary flow evolution and cooling effectiveness of the non-axisymmetric endwall turbine vane are to be investigated. The influence of the upstream slot (mass flow rate, preswirl, and incidence) and endwall film cooling (blow ratio and incidence) parameters on the aerothermal characteristics of the non-axisymmetric endwall turbine vane are to be systemically analyzed. The flow/heat transfer coupling mechanisms of the non-axisymmetric endwall turbine vane under the effect of the upstream slot and film cooling hole injection is to be revealed. The action mechanism of the aerothermal performance variation of the non-axisymmetric endwall turbine vane is to be clarified. The non-axisymmetric endwall profiling and endwall cooling layout methodology for decreasing the secondary flow loss and improve the comprehensive cooling effectiveness of turbine vane endwall are to be proposed. The presented research project can provide the basic theory and technical support for the higher aerodynamic efficiency and safety of the high-loaded turbine vane design.

对考虑槽缝和气膜孔射流冷气掺混作用下高负荷透平静叶非轴对称端壁气动和传热性能开展详细地实验测量和数值分析。建立高负荷透平静叶端壁上游槽缝和端壁气膜孔射流冷气掺混作用下非轴对称端壁气动传热性能参数测量和流场可视化实验系统，全面研究槽缝结构和端壁气膜孔布局对静叶非轴对称端壁二次流发展和冷却效率的影响规律，系统分析不同槽缝射流（流量、预旋和入射角）和端壁气膜冷却（吹风比和入射角）参数时静叶非轴对称端壁气热性能的变化特性。揭示槽缝和气膜孔射流冷气掺混作用下高负荷静叶非轴对称端壁流热耦合机理，阐明高负荷静叶非轴对称端壁气热性能变化的作用机制，提出槽缝和气膜孔射流冷气掺混作用下高负荷静叶减少二次流损失和提高端壁综合冷却效率的非轴对称端壁造型和端壁冷却结构布局设计方法。旨在为设计具有更高效率和安全性的高负荷透平静叶提供理论基础和技术支撑。

高气动损失和高热负荷特征的高负荷透平静叶端壁对其造型设计和冷却布局带来了挑战。项目采用数值模拟、实验测量和理论分析的方法开展高负荷燃气透平静叶端壁气热耦合机理与非轴对称端壁优化设计和高效冷却布局研究。发展完善了射流冷气作用下高负荷透平静叶端壁气热性能数值模拟方法，设计搭建了射流冷气作用下透平静叶端壁气动性能和传热特性的实验测量平台，系统深入研究了射流冷气参数和冷却结构布局对高负荷透平静叶端壁气动性能和传热冷却特性的影响特性。提出了在静叶上游槽缝入射段与端壁连接处的过渡圆角结构和端壁间错位设计方案，相比常规槽缝结构，过渡圆角结构和错位设计时静叶附近端壁的冷却效率提高23.1%。设计了高负荷透平静叶端壁间断上游槽缝、静叶前缘气膜孔排和静叶前缘根部射流槽冷却布局，验证了与基准冷却布局相当的冷却效率且消耗二次冷却空气比基准冷却布局减少13.3%，并具有较小的气动损失。探究了真实运行工况下端壁不重合度下燃气透平收敛端壁的热负荷、近壁面二次流结构和静叶气动损失。静叶进口台阶结构使轴对称端壁静叶总压损失增大了0.17% ~ 1.5%，且进口台阶结构越靠近静叶前缘，总压损失越大。揭示了进口不重合造成的透平静叶轴对称造型端壁传热变化规律和近壁面流动机理。提出减少二次流损失和提高冷却效率的高负荷透平静叶非轴对称端壁设计优化系统和高效冷却布局，完成了透平静叶多目标非轴对称端壁优化设计。揭示了非轴对称端壁通过改变二次流结构扩大上游槽缝射流在压力侧端壁覆盖面积的作用机理，实现了端壁冷却效率在槽缝预旋射流等非设计气膜冷却工况下提升了1.0%-3.0%。项目研究工作阐明了高负荷燃气透平非轴对称端壁的二次流与射流冷气的相互掺混机制，揭示了非轴对称端壁提升高负荷透平静叶端壁气热性能的物理机理，为低气动损失和高冷却效率的高负荷透平静叶端壁型线设计和冷却布局提供理论依据和技术支撑。