采用仿海鸥翼型叶片提升轴流风机气动性能的研究

A Study on the Aerodynamic Performance Improvement of Axial Flow Fans Using the Bionic Blades Inspired by Seagull Wings

为提升轴流风机的气动性能,受到具有良好滑行飞行性能的海鸥翅膀独特的翼型结构的启发,本文研究通过提取海鸥翅膀特定截面位置处的翼型结构应用于轴流风机的叶片设计中,考察了叶片仿生设计对空调器用轴流风机气动性能的影响。首先采用数值计算方法求解定常流动雷诺时均Navier-Stokes方程,对仿海鸥翼型叶片的轴流风机的气动性能及其内部流场进行分析,然后采用大涡模拟方法和FW-H声类比方法对轴流风机的气动噪声进行数值预测。结果表明:在相同的设计转速下,仿海鸥翼型叶片的轴流风机的气动效率提高了3.1%;在相同风量条件下,仿海鸥翼型叶片的轴流风机的噪声相比于原型风机降低了约1.0dB(A)。采用仿海鸥翼型叶片,风机叶片表面的静压分布均匀,叶片中段的压力脉动明显减少。同时,在风机进口轮毂处和叶顶区域,流动分离被抑制,叶片尾迹涡脱落引起的气流脉动和气流不均匀性相对减弱,这就有效提升了轴流风机的气动性能。

In order to improve the aerodynamic performance of axial flow fan,inspired by the unique structure of seagull wings with good gliding flight performance,this study investigates the effects of blade bionic design on the aerodynamic performance of axial flow fan used in the air conditioners by extracting wing structures at a specific cross-sectional position of the seagull wings.Firstly,the numerical method is used to solve the Reynolds averaged Navier-Stokes(RANS)equations,and the aerodynamic performance and internal flow fields of the axial flow fan with bio-seagull wing blades are analyzed numerically.Then,the large eddy simulation(LES)method and Ffowcs-Williams and Hawkings(FW-H)acoustic analogy theory are adopted to numerically predict the aerodynamic noise of the axial flow fan.The results show that at the designed rotational speed,the aerodynamic efficiency of the axial flow fan with bionic blades based on the seagull wings is improved by 3.1%.At the same flow rate condition,the aerodynamic noise of the axial flow fan with bionic blades is reduced by 1.0 dB(A)compared to the prototype fan.By using the bionic blades inspired by the seagull wings,the static pressure distribution on the blade surfaces of the axial flow fan is uniform,and the pressure pulsation in the middle section of the blade surfaces is significantly reduced.At the same time,the flow separation is suppressed effectively at the inlet hub and blade tip area of the axial flow fan,and the airflow pulsation and non-uniformity caused by blade wake vortex shedding are relatively weakened,which improves the aerodynamic performance of the axial flow fan.