摘要
对带有周向前弯和周向后弯叶片的低压轴流风扇,采用NI采集平台和双丝热线采集单元相结合的测量技术试验研究非设计工况下周向弯曲叶片的内部不稳定流动发展规律。对若干工况叶轮进出口三维流场进行详细测量,基于测量结果分析轴向、周向和径向方向的平均速度及湍流脉动速度,获得叶片周向弯曲叶轮内变工况下瞬态流场特性;通过对湍流度、雷诺应力和速度频谱分析,考察非设计工况下叶片周向弯曲叶轮固有的瞬态特性影响,分析进口来流扰动特征。研究结果显示NI采集平台和双丝热线采集单元整合的试验测量系统,成功测量低压周向弯曲叶轮变工况下的进出口三维流场,为多场同步测量提供技术参考;变工况下弯掠叶片对上下端壁区的不稳定流动具有显著的抑制作用,对于扩大稳定工作范围有着积极的作用;进口来流较高的湍流度主要存在近上下端壁区域,周向弯曲叶片对来流湍流度的影响主要集中在这两个区域;这些扰动主要集中于低频段,并呈宽频特性。
The unsteady characteristic of the inner flow in lower pressure axial fans with circumferential forward-skewed blades, backward-skewed blades is investigated experimentally at off-design conditions. The unsteady three-dimensional flow in circumferential skewed rotors upstream and downstream according to flow rates is successfully measured with a NI data collection platform and a hot-wire CTA unit （with a X probe）. Based on the measurement results, axial, circumferential and radial components of the averaged velocity and turbulent velocity are analyzed to obtain the aerodynamic performance of circumferential skewed rotors; and the turbulent intensity, Reynold tensor and velocity spectrum are discussed to investigate the intrinsic unsteady flow in these rotors. The results show that the three-dimensional flow is captured by this measure system, which can be used for multi-physics measurement; the circumferential skewed blades are found to control the unsteady flow in the shroud and hub region at off-design conditions to expand stable operation; the inlet disturbed flow under off-design conditions was observed in the shroud and hub region, with low frequency and wide band characteristic.
出处
《机械工程学报》
EI
CAS
CSCD
北大核心
2013年第4期154-162,共9页
Journal of Mechanical Engineering
基金
中央高校基本科研业务费专项资金资助项目(JUSRP111A17)
关键词
热线
轴流风扇
不稳定流动
Hot-wire
Axial flow fan
Unsteady flow
