基于转捩模型的吸附式压气机正弯叶片数值研究

Numerical Study of Positively Curved Blade in Aspirated

关键词:  航空发动机  吸附式压气机  转捩模型  正弯叶片  数值研究

Key words:  Aircraft engine  Aspirated compressor  Transition model  Positively curved blade  Numerical investigation

摘要:

采用三维数值方法研究了吸附式压气机扇形叶栅中正弯叶片的流场和气动性能，通过对比分析三种不同的孔式抽吸方案，以探讨附面层抽吸抑制三维流动分离、减小损失的机理。首先通过与前期实验数据的对比，校核了数值计算代码的可靠性，所得到的流场特性与实验数据有较好的一致性；其次通过在常规直叶片和正弯叶片中采用孔式附面层抽吸方法，以对比不同叶片积迭形式时附面层抽吸的效果，并探讨了通过改善抽吸设计方案提高抽吸效果的机理。结果表明，采用孔式抽吸可以较好地控制直、弯叶栅内的三维流动分离，抽吸后的吸力面气泡式分离消失，每个抽吸孔下游形成了新的基于抽吸孔特征的分离流动结构；抽吸策略的调整改善了角区的三维流动分离，尾迹旋涡的发展以及强度得到有效抑制。

Abstract:

Three-dimensional numerical method is adopted to study the flow field and aerodynamic performance of an aspirated compressor cascade with positively curved blades. Through a comparative analysis of three different hole-type suction schemes，the mechanisms of boundary layer suction inhibiting the 3D flow separation and reducing the loss were discussed. Firstly，the reliability of numerical calculation code is checked against the experimental data available from literature. The numerical flow-field characteristics has good agreement with the experimental data. Then，the effects of blade stacking styles on boundary layer suction are analyzed by using hole-type aspiration in straight and positively curved cascade，respectively，and the mechanisms for increasing the aspiration effect by improving aspiration-hole design schemes are discussed. The results show that the hole-type aspiration can control the three-dimensional flow separation well both in straight and positively curved cascades. With aspirated，the separation bubble on suction surface disappears and the new separation flow structures based on the aspiration-hole characteristics are generated at the downstream of the aspiration holes. The aspiration strategies are adjusting to improve the three-dimensional separation flow in the corner，therefore the development and intensity of wake vortex are restrained obviously.