针对轴流压气机的非轴对称端壁造型优化设计

Optimized Non-Axisymmetric Endwall Contouring for Axial Compressor

针对某轴流压气机构建了一种新的非轴对称端壁造型,该造型可通过抑制角区分离来达到减小通道内二次流损失的目的。首先,在设计工况下,针对基准叶栅建立非轴对称端壁的自动优化设计方法。然后,在设计和非设计工况下,用NUMECA/Fine turbo模块分别对基准叶栅和优化叶栅进行定常流场计算。结果表明,两种工况下,优化叶栅有效抑制了角区分离,原因为非轴对称端壁造型改变了通道内的涡系结构;优化叶栅出口截面总压损失系数显著降低,叶栅出口气流角更加均匀和平衡。

A novel non-axisymmetric endwall contouring was presented for an axial compressor cascade to reduce secondary flow losses by suppressing the corner separation. Firstly, a design methodology based on automated optimization was put forward for the baseline cascade at design conditions. Hereafter, with re- spect to the contoured endwall and the baseline cascade, steady numerical simulations were conducted in NUMECA/Fine turbo to gain further understanding of the effects of endwall contouring in both design and off-design conditions. The results demonstrated that with the contoured endwall for both conditions, the cor- ner separation was enormously suppressed owing to the modification of vortex structures in the blade chan- nel. Furthermore, the total pressure loss coefficient was largely decreased in the outlet plane, and the out- flow angles become more uniform and balanced.