极端进气下压气机内部流动损失时-空演化机制及静叶非均匀减损设计研究

The distributed propulsion system has attracted widely attentions because it can reduce the aircraft fuel consumption by about 5%-15% through ingesting the boundary layers on the fuselage using fan/compressors. Boundary layer ingestion (BLI) results in a non-uniform inflow at the compressor inlet and makes the compressor continuously operating under harsh conditions, thus creating a new challenge for compressor aerodynamic design. The non-uniform inflow would also lead to a non-axisymmetric flow structure in the compressor. However, this flow structure has not been fully taken into account in the conventional aerodynamic design process of a compressor. Based on these issues, the applicant wants to conduct research on non-uniform aerodynamic design to reduce the negative impacts of non-uniform flows in compressors. Firstly, numerical and experimental investigations will be carried out to explore the temporal-spatial evolutions of the non-uniform flows in the compressor caused by BLI inflow distortion. Then, the mechanisms of influence of non-uniform flow structures on the temporal-spatial evolutions of flow losses would be studied in depth. The losses will be related to the aerodynamic design parameters and a database for the key design parameters would also be constructed. In the meanwhile, an analytical model will be established to weigh the influence of key design parameters on the flow losses. Finally, an efficient combined optimization method will be developed to extract the non-uniform aerodynamic design application rules for BLI compressors. Based on the design application rules, a non-uniform aerodynamic design will be conducted and validated in a BLI compressor. The proposal has a significant potential for enriching the current compressor aerodynamic design strategies and improving the overall aerodynamic benefits gain for the distributed propulsion system.

分布式动力系统通过动力风扇抽吸机身表面边界层能够使飞行器耗油率降低约5%-15%，受到广泛关注。边界层抽吸（BLI）使压气机进口产生强非均匀进气边界，长期持续工作于极端进气条件给压气机气动设计带来了新的挑战。非均匀进气边界在压气机内部产生复杂的非对称流动结构，传统的压气机气动布局未曾考虑这一流动特征。申请人拟针对非对称流动结构开展压气机非均匀气动布局探索研究工作：首先，数值和实验研究BLI型畸变所致非对称流动在压气机内部时-空发展演化规律；然后，深入探究非对称流动对压气机内部流动损失时-空演化的作用机制，与气动设计参数相关联，建立关键气动设计参数数据库及关键参数对流动损失影响权重分析模型；最后，发展高效组合气动优化方法提炼并形成BLI型压气机非均匀气动设计应用准则，开展非均匀气动布局设计及验证。研究成果对进一步丰富压气机气动设计策略、提升分布式动力系统整体气动收益具有潜在的重要意义。

分布式风扇推进系统通过动力风扇抽吸机身表面边界层能够大幅降低飞行器燃油消耗，受到广泛关注。边界层抽吸（BLI）使风扇进口产生强非均匀进气边界，并在风扇内形成复杂的非对称流动结构，传统风扇气动布局未曾考虑这一流动特征，因此，持续工作于非均匀进气工况就给BLI风扇气动设计带来了新挑战。本项目主要针对非均匀进气下风扇内部流动损失发展演化机制及静子叶片空间非均匀气动设计展开研究，研究成果包括：（1）畸变流场与转子叶片相互作用导致流量发生重新分配，使转子来流速度（轴向、周向和径向分量）、攻角以及相对马赫数呈现出空间非均匀分布特征，建立了气动参数与叶片负荷之间的物理关联；（2）研究了转子在不同典型周向位置（非畸变区、进入畸变区、畸变区中心以及离开畸变区）时叶尖泄漏流与激波相互作用以及泄漏涡发展演化规律，当转子离开畸变区时，叶尖负荷显著增大，泄漏涡增强并与通道内前移激波作用导致涡破碎，而其他周向位置未出现此现象，揭示了BLI风扇局部叶片通道激波诱导泄漏涡破碎的损失形成机制。进一步研究表明，静叶通道内气动损失主要表现为流动分离损失，并呈现出周向和径向非均匀分布特征；（3）发展了基于分区组合替代模型的高精度非线性数据/变量关联技术，基于此，建立了基于负荷空间分布调控的风扇/压气机气动优化设计方法；（4）针对BLI风扇内部流动损失空间非均匀分布特征开展了静叶空间（周向和径向）非均匀气动布局设计，使静叶流动损失降低约18.2%，风扇级绝热效率提升约0.83%，在全工况范围内，整级风扇在总压比保持基本不变的情况下气动效率都显著增加。研究成果能够为高性能BLI风扇气动设计提供理论和方法支撑。本项目共计发表SCI期刊论文7篇，EI期刊论文1篇，授权国家发明专利2项，受理发明专利1项，培养博士生1名、硕士生2名，研究成果还获得2020年中国航空学会科学技术二等奖，项目负责人入选北京市科协青年人才托举工程（2022-2024）。