叶片尾缘凹陷结构对空调用轴流风机性能的影响
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摘要
根据建立的窗式空调用室外机的数值仿真模型,首先对室外轴流风机的风量-静压特性进行数值研究,通过与实验测量的比较,验证了本文数值计算的有效性。考虑到轴流风机降噪的要求,本文研究了两种叶片尾缘凹陷结构对轴流风机气动性能和噪声的影响。进一步考虑到轴流风机风量的提升要求,考察了叶片高度变化对轴流风机风量和噪声的影响。研究结果表明,轴流叶片尾缘的凹陷可以改善叶片表面压力分布,减小叶轮叶片尾迹,降低室外风机气动噪声。在不同转速下对空调用室外轴流风机的风量和噪声进行测量,发现在小风量条件下采用叶片尾缘凹陷结构可降低风机噪音1.0d B以上;在大风量条件下,采用叶片尾缘凹陷结构,降噪效果有所下降。如果保持叶轮转速和半径不变,在可装配条件下,叶片高度从58mm增加到79mm,空调用室外轴流风机的风量较原型增加了75m~3/h,增幅达15.5%。
A numerical model is used study the flow rate and static pressure characteristics of an outdoor axial fan for a window air conditioner. By comparing the numerical results with experimental measurement data, the validity of the simulation method is verified. The influence of two kinds of blade trailing edge sag structures on the noise level and the aerodynamic performance is studied. Additionally, the influence of the blade height on the flow rateand noise level is investigated. The results show that an appropriate sag structure of the blades can improve the pressure distribution around the blades, weaken the blade wake and reduce the noise of the fan. The flow rate and noise emission of the outdoor axial fan are measured for varying rotational speeds. For low flow rates, the noise is reduced by 1.0 d B when trailing edge sag structures are used. For large flow rates, however, the noise reduction effect is reduced. Increasing the blade height form 58 mm to 79 mm, while keeping the impeller speed and radius constant, the flow rate of the outdoor axial fan is increased by 75 m3/h or 15.5%.
A numerical model is used study the flow rate and static pressure characteristics of an outdoor axial fan for a window air conditioner. By comparing the numerical results with experimental measurement data, the validity of the simulation method is verified. The influence of two kinds of blade trailing edge sag structures on the noise level and the aerodynamic performance is studied. Additionally, the influence of the blade height on the flow rateand noise level is investigated. The results show that an appropriate sag structure of the blades can improve the pressure distribution around the blades, weaken the blade wake and reduce the noise of the fan. The flow rate and noise emission of the outdoor axial fan are measured for varying rotational speeds. For low flow rates, the noise is reduced by 1.0 d B when trailing edge sag structures are used. For large flow rates, however, the noise reduction effect is reduced. Increasing the blade height form 58 mm to 79 mm, while keeping the impeller speed and radius constant, the flow rate of the outdoor axial fan is increased by 75 m3/h or 15.5%.
引文
[1]周水清,王军,王兴双.Bezier函数型弯叶片的轴流风扇气动性能研究[J].华中科技大学学报,2013,41(3):106-110.
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[11]叶学民,张建坤,李春曦.叶顶形状对轴流风机气动噪声影响的数值研究[J].动力工程学报,2017,37(7):558-567.
[12]Liu Yang,Li Zhe,Lin Pei-Feng,et al.Effect of uneven circumferential blade space on the performance of small axial flow fan[J].Journal of Thermal Science.2016,25(6):492-500.
[2]游斌,程志明,马列,等.齿形尾缘轴流叶轮内流数值分析与实验研究[J].工程热物理学报,2007,28(4):592-595.
[3]唐俊,王军,隽智辉,等.正弦锯齿尾缘对轴流风机尾迹及气动性能的影响[J].工程热物理学报,2017,38(10):2145-2150.
[4]刘小民,赵嘉,李典.单圆弧等厚叶片前后缘多元耦合仿生设计及降噪机理研究[J].西安交通大学学报,2015,49(3):1-10.
[5]潘虹宇,杨爱玲,游骏杰,等.加弯叶型在轴流风机噪声噪声控制中的应用研究[J].热能动力工程,2016,31(1):99-105.
[6]孙扬智,肖世德,徐鑫凯,等.轴流风机旋转叶片的气动噪声分析[J].噪声与振动控制,2017,36(4):124-129.
[7]Zhu Li-Fu,Jin Ying-Zi,Li Yi,et al.Numerical and experimental study on aerodynamic performance of small axial flow fan with splitter blades[J].Journal of Thermal Science.2013,22(4):333-339.
[8]Zhang Li,Jin Ying-Zi,Jin Yu-Zhen.Effect of tip flange on tip leakage flow of small axial flow fans[J].Journal of Thermal Science,2014,23(1):45-52.
[9]罗黎,王琪,袁明新,等.基于流固耦合的轴流风机结构优化与分析[J].江苏科技大学学报(自然科学版),2017,31(1):61-65.
[10]杨恩军,周海宾,刘向阳.轴流风机流量异常成因分析[J].中国新技术新产品,2017(7):50-52.
[11]叶学民,张建坤,李春曦.叶顶形状对轴流风机气动噪声影响的数值研究[J].动力工程学报,2017,37(7):558-567.
[12]Liu Yang,Li Zhe,Lin Pei-Feng,et al.Effect of uneven circumferential blade space on the performance of small axial flow fan[J].Journal of Thermal Science.2016,25(6):492-500.