多级轴流压气机出口级转子扩张通道优化设计

为提高多级轴流压气机后面级气动性能，针对某多级轴流压气机出口级转子搭建了基于遗传算法和神经网络代理模型的扩张通道压气机优化设计平台，并对其进行扩张通道优化设计研究。根据优化得到的数据库分析了各设计参数对效率和裕度的影响规律。在优化所得解集中选择了两个扩张通道设计方案，探究了其对效率和裕度的影响规律和机制。结果表明:扩张通道设计可使出口级转子在设计流量点的负荷提高12.1%、效率提高1.28%，同时获得12.50%的裕度改善量。基于当地熵产率损失模型可得，扩张通道转子相较于原型转子，其上下端壁损失增加，叶型损失减小。扩张通道转子近失速点堵塞系数变小是其裕度提升的主要原因。 

Design optimization of exit stage rotor with diffuser passage in multi-stage axial compressor

In order to improve the aerodynamic performance of the rear stages of multi-stage axial compressor，an in-house optimization design platform for diffuser passage compressors based on genetic algorithm and neural network surrogate model was built and applied into the optimization design of an exit rotor with diffuser passage.Impacts of the design parameters on efficiency and stability improvement were analyzed based on optimization database.Two optimized diffuser passage designs were selected from the optimization solution set and their influencing rules and mechanisms on efficiency and stability were further studied.Results showed that application of diffuser passage design can improve the load coefficient by 12.1% and efficiency by 1.28% at design mass flow rate，the improvement of stall margin by 12.50% can also be obtained.According to the local entropy generation rate model，the loss of the upper and lower endwalls of the diffuser passage rotor was increased compared with the origin rotor，whereas the loss of profile was reduced. The main reason for stall margin increase of the diffuser passage rotor was the decrease of blockage coefficient near the stall point.