分流叶片前缘掠对微小型离心压气机气动性能影响

Effects of Leading-Edge Sweep Angle of Splitter Blade on Aerodynamic Performance of Micro-Centrifugal Compressor

关键词:  离心压气机  分流叶片  前缘掠角  流场特性  气动性能  数值模拟

Key words:  Centrifugal compressor  Splitter blade  Swept angle of leading edge  Flowfield characteristics  Aerodynamic performance  Numerical simulation

摘要:

为了研究分流叶片前缘掠角对微小型离心叶轮流场及气动性能的影响，应用数值模拟及理论分析，对一带有分流叶片的离心叶轮进行了研究。结果表明：分流叶片前缘后掠增强离心叶轮气动性能的机制，一方面为分流叶片对主叶片泄漏涡的分流效应，以及分流叶片攻角增大致使其吸力面高速低压气流对主叶片泄漏涡的引射效应；另一方面，随分流叶片前掠角度增大，其肩部的膨胀及压缩效应增强，对主叶片压力面气动干扰增强，使主叶片压力面负荷降低，当分流叶片后掠角度增大时，气流相对分流叶片前缘攻角变大使分流叶片气动负荷变大，另外，攻角变大导致分流叶片吸力面气流加速、流线弯曲变大，气动负荷增大。在进行分流叶片设计时，权衡结构重量、气动性能等因素，建议分流叶片前缘后掠角取值在8°~16°。

Abstract:

To investigate the effects of swept angle of leading edge of the splitter blade on flowfield characteristics and aerodynamic performance of a miniature centrifugal compressor， a miniature centrifugal compressor was studied based on theoretical analysis and numerical simulation. The results show that the mechanisms of the leading-edge backward sweep of splitter blade improving the performance of the compressor are， on the one hand， the splitting effect of the splitter blade on the leakage vortex of the main blade and the ejection effect of the high-speed and low-pressure airflow near the suction surface of the splitter blade on the leakage vortex because of increasing of angle of attack near the splitter blade. On the other hand， the expansion and compression effects of the flowfield near the shoulder of the splitter blade are enhanced， the aerodynamic effects on the pressure surface of the main blade are also promoted， and the load on the pressure surface of the main blade is reduced， with the increase of the forward-swept angle of the splitter blade. When the backward-swept angle of the splitter blade is enlarged， the aerodynamic load on the splitter blade increases with the change of the angle of attack. In addition， the increased angle of attack leads to the acceleration of the flow on the suction surface of the splitter blade and the magnified curvature of the streamline and the aerodynamic load is amplified simultaneously. In the process of splitter blade design， it is necessary to trade off among the structural weight， aerodynamic performance and other factors， and the backward-swept angle of the leading-edge of the splitter blade should be in the range between 8° and 16°.