基于B样条的斜流压气机机匣处理优化设计

Design and Optimization of Casing Treatment Based on B-spline Curves in a Mixed-Flow Compressor

针对一台高负荷单级斜流压气机轴向缝机匣处理搭建了基于B样条曲线造型的优化平台,并进行了多目标优化设计,根据优化得到的数据库分析了各设计参数对机匣处理效率与扩稳性能的影响规律。在优化所得的非劣解集中选择了三个典型轴向缝机匣处理设计,探究了其对于压气机效率与稳定性的影响规律和机制。结果表明轴向缝机匣处理在动叶叶顶区域通过抽吸作用施加了一股循环流动,减轻了叶顶与通道中的堵塞。综合考虑稳定裕度与效率指标,最终得到的轴向缝机匣处理设计在仅损失0.28%峰值效率的情况下得到了19.84%的稳定裕度扩宽量。

In this paper,an in-house optimization design platform of axial slot casing treatments based on B-spline curves in a single-stage highly-loaded mixed-flow compressor is constructed and applied in a multi-objective optimization.Impacts of design parameters on efficiency and stability improvement are analyzed based on the optimization database.Three optimized slot designs are selected from the Pareto Front.Their influencing rules and mechanisms on stability and eficiency are further studied.Results show that the application of slots would generate a circulated flow,which exerts suction and reinjection effects at the rotor tip region and alleviate the blockage in the tip region and blade passages.Considering both stall margin and efficiency,the final optimal casing treatment design improves the stall margin by 19.84% with an acceptable 0.28% reduction in peak efficiency.