为厘清联合成型设计空间各造型方法对涡轮叶栅性能提升的贡献,将基于总变差分析的全局敏感性分析方法与平行坐标系及直方图、散点图等可视化技术相结合,提出了将多源数据挖掘信息进行融合的设计空间知识挖掘框架,并利用该框架对某小展弦比叶栅端壁/叶身联合成型设计空间进行知识挖掘.结果表明:叶栅气动损失增减对基元型线微调十分敏感;非轴对称端壁所带来的损失减少量与型线微调接近,但设计空间内不同非轴对称端壁样本性能波动较小,导致其重要性被全局敏感性分析方法低估;虽然单独采用弯叶片难以整体降低小展弦比叶栅损失,但将弯、型线微调和非轴对称端壁造型相结合可获得"1+1+1>3"的性能增益;在端壁/叶身联合成型设计空间内,将基元型线朝着后加载方向微调,并采用喉部附近下凹较深的非轴对称端壁造型及反弯叶片设计,可获得气动损失较小的叶栅设计.研究结果明晰了端壁/叶身联合成型设计空间优化解特征,可为类似小展弦比叶栅设计优化提供借鉴.
To enhance understanding of the role different cascade profiling techniques play in im-proving turbine cascade performance within the combined design space,a knowledge mining framework is proposed.This framework integrates data mining information through the analysis of variance-based global sensitivity analysis method and employs visualization techniques like par-allel axis,histogram and scatterplot.By using this framework,knowledge mining of the non-axi-symmetric endwall/blade combined parameterization design space of a low aspect ratio cascade is conducted.It reveals that the aerodynamic loss of the cascade is highly influenced by the section profiling.The reduction in loss achieved through the implementation of a non-axisymmetric end-wall is comparable to that of section profiling.However,it is observed that the performance vari-ations among different samples of non-axisymmetric endwall are relatively small,leading to the underestimation of its significance by the global sensitivity analysis method.Furthermore,it is found that utilizing only a bending curved blade is unlikely to yield a reduction in cascade loss.However,by combining blade bending,section profiling and non-axisymmetric endwall,it is pos-sible to achieve a performance gain that exceeds the sum of the individual contributions("1+1+ 1>3").Within the combined design space of non-axisymmetric endwall/blade parameterization,it is observed that a cascade with low aerodynamic loss can be achieved by adjusting the section profile towards an after-loading style and incorporating a non-axisymmetric endwall with deep concave near the throat and negatively bending blade as well.In conclusion,this research has successfully elucidated the characteristics of optimized solutions within the end-wall/blade joint forming design,offering reference for the design optimization of similar low aspect ratio cascades.The above findings have effectively clarified the characteristics of the optimized solutions within the endwall/blade combined design space,offering guidance for the design optimization of similar low aspect ratio cascades.