基于曲率诱导“伪激波”的高负荷吸附式压气机叶片设计

Design of Highly Loaded Aspirated Compressor Blade Based on Curvature Induced ‘Pseudo Shock’

关键词:  曲率诱导“伪激波”  吸附式压气机  流动分离  附面层抽吸  叶片设计

Key words:  Curvature induced ‘Pseudo Shock’  Aspirated compressor  Flow separation  Boundary suction  Blade design

摘要:

为了充分发挥吸附式压气机叶片的潜力，基于“曲率诱导‘伪激波’”理念的吸附式压气机叶片设计方法，设计了三种高负荷吸附式叶片；采用数值模拟方法探究了不同设计策略下叶片抽吸前、后的流动机理和抽吸对流动分离的控制机制；针对曲率诱导“伪激波”理念的吸附式叶片Blade-M （“伪激波”位于53.1%轴向弦长处）开展了端壁/吸力面组合抽吸的研究。结果表明：曲率诱导“伪激波”可有效适应抽吸承担逆压梯度的本质特性，设计的三种吸附式叶片扩散因子高达0.73；采用吸力面单独抽吸可有效消除叶片Blade-M和Blade-L （“伪激波”位于34.8%轴向弦长处）的尾缘分离，损失系数分别降低 66.7% 和 71.8%，但吸力面抽吸无法有效控制高负荷叶栅的角区分离；采用端壁/吸力面组合抽吸后，Blade-M叶栅通道内的尾缘分离和角区分离均被有效控制，在6.6%的抽吸系数下损失系数降低了87.3%；在大攻角条件下，基于曲率诱导“伪激波”的吸附式叶片依然可保持无分离的特性，显示了该种叶片对变工况抽吸的适应能力，为发展高稳定裕度、高负荷吸附式压气机提供了科学依据。

Abstract:

In order to fully exploit the potential of aspirated compressor blade， three kinds of highly loaded aspirated blades were designed based on the concept of curvature induced ‘Pseudo Shock’. The flow mechanism with/without suction and the control mechanism of suction to flow separation under different design strategies were investigated by numerical simulation method. Finally， the investigation of combination suction method on endwall/suction surface of Blade-M （the ‘Pseudo Shock’ was settled at 53.1% axial chord） was carried out. As a result， the ‘Pseudo Shock’ induced by curvature can effectively adapt to the essential characteristics of suction of bearing the adverse pressure gradient. The diffusion factor of three newly designed aspirated blades were up to 0.73. In three dimensions， the suction surface suction can effectively eliminate the trailing separation of Blade-M and Blade-L （the ‘Pseudo Shock’ was settled at 34.8% axial chord）， and the loss coefficient were reduced by 66.7% and 71.8%， respectively， but the corner separation of highly loaded cascade can not be effectively controlled. After combining endwall suction and suction surface suction， both trailing separation and corner separation of Blade-M were effectively controlled and the loss coefficient was reduced by 87.3% with the suction coefficient of 6.6%. Under high incidence angle， the combined suction method can still effectively eliminate the flow separation of the Blade-M， which shows the adaptability of the variable conditions and provides a scientific basis for the development of large stability margin and highly loaded aspirated compressor.