附面层吸入条件下非轴对称静子对风扇流场影响数值研究

Numerical study on effects of non-axisymmetric stator on fan flow field under boundary layer ingestion

关键词:  附面层吸入  非轴对称静子  扩压因子  失速裕度  角区分离

Key words:  Boundary layer ingestion  Non-axisymmetric stator  Diffusion factor  Stall margin  Corner separation

摘要:

附面层吸入导致进气道与风扇气动交界面处产生严重的总压、旋流畸变，进而使得风扇效率、稳定性降低，是制约其应用的主要问题之一。为了提高风扇的抗畸变能力，本文对风扇静子进行了非轴对称设计和数值仿真计算。结果表明：相较于原型风扇，非轴对称静子效率提高0.31个百分点，失速裕度提高50.5%，风扇内部流场有明显改善，扩压因子减小，畸变区静叶叶尖吸力面角区分离范围显著降低，叶片通道通流能力上升。非轴对称静子改型方案通过改变畸变区静叶进口几何角与弦长，使静叶冲角基本不变，稠度增加，气流在吸力面上不易发生分离，从而使得角区分离范围减小，流动损失降低，风扇性能提升。

Abstract:

The boundary layer ingestion leads to serious total pressure and swirl distortion at the aerodynamic interface between the inlet and the fan， thus reducing the efficiency and stability of the fan， which is one of the main problems restricting its application. In order to improve the anti distortion ability of the fan， the fan stator is non- axisymmetrically designed and numerically simulated. The results show that compared with the original fan， the non-axisymmetric stator efficiency increased by 0.31%， the stall margin increased by 50.5%， the internal flow field of the fan is significantly improved， the diffusion factor is reduced， the corner separation range of the suction surface of the vane tip in the distortion zone is obviously cut down， and the flow capacity of the vane channel increases. The non-axisymmetric stator modification scheme changes the vane inlet metal angle and chord in the distortion zone， so that the incidence angle is basically unchanged， the solidity increases， and the airflow is not easily separated on the suction surface， thereby reducing the corner separation range， the dynamics loss is reduced， and the performance of the fan is improved.