采用弯-掠叶片的压气机叶栅变冲角性能研究

Investigation of swept and curved compressor cascade performance under different incidences

关键词:  压气机  叶栅  叶型  冲角+  气动性能

Key words:  Air compressor  Cascade  Blade airfoil  Incidence~+  Aerodynamic　characteristic

摘要:

利用经过实验数据验证的CFD软件对采用不同掠型叶片的压气机叶栅±20°冲角范围内性能进行了数值研究。结果表明,在任一冲角下,与直叶栅比,前掠和弯掠叶栅中静压分布呈反"C"型规律,端部损失下降,中部损失增加,后掠叶栅则情况相反;随冲角增加,前掠和弯掠叶栅中低能流体在中部积聚增多,损失增加明显;算例中,尽管叶栅总损失有所增加,但弯掠叶栅变工况特性好,可最大限度控制附面层流体在端区积聚,避免角区分离,从而显著加大压气机稳定工作区间,对提高航空发动机总体性能意义较大。

Abstract:

The performances of compressor cascades with swept blades are studied numerically by use of commercial validated CFD software.Compared to straight cascade, for all incidences, reverse "C" type static pressure distribution is built up for the forward swept and swept-curved cascade with the energy loss reduction at the two endwalls and increase at the midspan; opposite results occur for the backward swept cascade. More low energy fluid accumulates at midspan of forward swept and swept-curved cascades with the increase of incidence, which causes the increase of energy losses. In this case, the off-design performance of the swept-curved cascade is good enough to control the accumulation of low energy fluid near endwalls and to avoid fluid separation in the corner and increase the surge margin.