When the aircraft cruising at high altitude, the aerodynamic performance of the compressor sharply decreases due to the enhanced boundary layer separation loss. Therefore, it is of great significance to design the high-performance airfoils suitable for low Reynolds numbers (Re) to improve the aerodynamic performance of compressor. In this paper, numerical simulations were carried out on a high-loaded subsonic compressor cascade V103 at low Re. Meanwhile, a multi-objective optimization of blade profile was performed to get optimal solutions, and data mining techniques were applied to extract valuable design knowledge from the optimal database. The results show that the Pareto-optimal airfoils achieve a maximum reduction of 27.32% in total pressure loss coefficient under design condition and 36.71% under near stall condition. Compared with the original airfoil, the curvature distribution law of the camber line with larger values at both ends and smaller values in the middle is advantageous for the performance of the compressor cascade under design condition. This distribution pattern causes a forward shift for the loading distribution of airfoils, accompanied by an earlier transition onset. Additionally, it reduces adverse pressure gradient at the rear part of suction surface, which suppresses the development and growth of laminar separation bubble and delays the separation of turbulent boundary layer. Under near stall condition, maintaining larger leading edge angle and uniform flow diffusion is beneficial for improving the performance of compressor cascade. This is because the larger leading edge angle reduces incidence angle, while the uniform flow diffusion inhibits a great flow separation.

中文翻译：

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低雷诺数高负载压气机翼型几何特征提取及流动机理分析

当飞机在高空巡航时，由于边界层分离损失增强，压气机的气动性能急剧下降。因此，设计适合低雷诺数（Re）的高性能翼型对提高压气机气动性能具有重要意义。本文对低 Re 下高负载亚音速压气机叶栅 V103 进行了数值模拟。同时，对叶片轮廓进行多目标优化以获得最优解决方案，并应用数据挖掘技术从最优数据库中提取有价值的设计知识。结果表明，帕累托最优翼型在设计工况下全压损失系数最大降低了27.32%，在近失速工况下全压损失系数最大降低了36.71%。与原翼型相比，两端值较大、中间值较小的弧线曲率分布规律有利于压气机叶栅在设计工况下的性能。这种分布模式导致翼型的载荷分布向前移动，并伴随着较早的过渡开始。另外，它还减小了吸力面后部的逆压梯度，抑制了层流分离气泡的发育和长大，延缓了湍流边界层的分离。在近失速工况下，保持较大的前缘角和均匀的流动扩散有利于提高压气机叶栅的性能。这是因为较大的前缘角减小了入射角，而均匀的流动扩散抑制了较大的流动分离。