摘要
为充分挖掘串列叶片对压气机扩稳增效的潜能,在对多级轴流压气机末级静子串列改型的基础上,选取不同叶高处前后排叶片相对位置、负载分配、弯掠特征及端壁轮廓等25个参数为设计变量,开展某工业用6.5级轴流压气机末级串列静子叶片与端壁的一体化优化设计研究,并采用随机森林方法对串列叶片几何参数进行特征重要性分析,提炼出串列参数设计指导。结果表明:优化后压气机末级在设计工况、近喘工况和近堵工况下的绝热效率分别提升4.81%、3.37%和8.195%;对于末级串列静子,最优串列参数随叶高变化而变化;调整前后叶片的弦长比与弯角比以实现串列叶片负荷前加载、调整叶片后掠与反弯以降低叶片端壁处负荷、设置叶中部分更大的周向交错度使缝隙区流体充分加速,均能有效降低末级串列叶片流动损失;串列叶片缝隙区尺寸,尤其是周向交错度,较其他参数对串列叶片性能的影响更为显著。研究成果应对压气机三维串列叶片设计具有参考价值。
In order to fully explore the potential of tandem blades to increase the stability and efficiency of axial compressors, a research is carried out on the integrated optimization design of tandem stator blades and endwall for the last stage of an industrial 6.5-stage axial flow compressor. Based on the tandem blading of the last-stage stator, a total of 25 parameters describing the relative positions of blades at different heights along the span, loading distribution, sweep and lean, and end wall contour are selected as the design variables. The random forest method is adopted to perform feature importance analysis of geometric parameters, and the design guide of tandem parameters is extracted. The results show that the adiabatic efficiency of the last stage is increased by 4.81%, 3.37% and 8.195%, respectively at design, near surge and near choke points after optimization. For the last-stage stator, optimal tandem parameters are different at different heights along the span. The flow losses within tandem blades can be effectively reduced by adjusting the chord ratio and camber ratio of the front and after blades for pre-loading of the front blade, adjusting the backward sweep and lean of the blades to reduce the loading at the end wall of the blades, and setting a large percent pitch in the middle part of the blades to fully accelerate the fluid in the gap area. The gap size, especially percent pitch, is more influential than the other parameters on the tandem blade performance. The outcomes in this study have reference value for the design of three-dimensional tandem blades of axial compressors.
作者
陈玲
琚亚平
李震
张楚华
CHEN Ling;JU Yaping;LI Zhen;ZHANG Chuhua(School of Energy and Power Engineering,Xi’an Jiaotong University,Xi’an 710049,China)
出处
《西安交通大学学报》
EI
CAS
CSCD
北大核心
2023年第1期164-174,共11页
Journal of Xi'an Jiaotong University
基金
国家重大科技专项资助项目(J2019-II-0017-0038,2017-II-0006-0020)。
关键词
轴流压气机
串列叶片
三维优化设计
随机森林
气动性能
axial flow compressor
tandem blade
three-dimensional optimization design
random forest
aerodynamic performance
