叶顶间隙非均匀对大型轴流风机性能的影响  

Influence of Non-Uniform Blade Tip Clearance on the Performance of a Large Axial Flow Fan

作　　者：成铠 陈云瑞 孟凡杰 李景银[1] CHENG Kai;CHEN Yunrui;MENG Fanjie;LI Jingyin(School of Energy and Power Engineering,Xi’an Jiaotong University,Xi’an 710049,China)

机构地区：[1]西安交通大学能源与动力工程学院,西安710049

出　　处：《西安交通大学学报》2022年第10期180-189,共10页Journal of Xi'an Jiaotong University

基　　金：国家自然科学基金资助项目(51876158)。

摘　　要：为了探索叶顶间隙沿周向非均匀变化对大型低压轴流风机性能的影响,以某民用大型低压轴流风机为研究对象开展研究,选择表征轴流风机周向非均匀间隙的两个关键参数——平均间隙水平、非均匀度为影响因素,通过定常、非定常的数值模拟,研究周向非均匀的叶顶间隙对风机外特性的影响,以及对叶顶间隙流动和流场变化的影响机理。结果表明:轴流风机平均间隙、非均匀度的增加均会造成风机效率和静压的下降,但平均间隙的改变对静压的影响明显大于非均匀度变化所产生的影响;叶顶间隙不均匀,会改变叶顶泄漏的起始位置和发展方向,在间隙较大处,叶顶泄漏不但有带涡核的主泄漏,还包括无涡核的附加泄漏,同时叶顶的泄漏流量会因受到前向叶片泄漏涡的卷吸而周期性地改变。该研究成果对低压轴流风机设计及高效运行具有一定的参考价值。This research was conducted to explore the influence of a non-uniform change of blade tip clearance along the circumferential direction on the performance of a large low-pressure axial flow fan.In this research,a large civil low-pressure axial flow fan was taken as the research object,with two key parameters(namely,the average clearance and the non-uniformity)representing the circumferential non-uniform clearance of the axial flow fan selected as the influencing factors.Steady and unsteady numerical simulations were conducted to research the influence of circumferential non-uniform blade tip clearance on the external characteristics of the fan,and on the blade tip clearance flow and flow filed change.The results show that both the increase in the average clearance and non-uniformity of the axial flow fan led to the decrease of the fan’s efficiency and static pressure,and the influence caused by the change of the average clearance is significantly greater than that by non-uniformity.When the clearance is large,blade tip leakage flows include not only the main leakage flow with a vortex core,but also an additional leakage flow without a vortex core.The non-uniform blade tip clearance will change the starting position and development direction of blade tip leakage flow.In addition,the blade tip leakage flow will be subject to a periodic change due to the entrainment of the leakage vortex from its leading blade.This research is helpful in the design and efficient operation of low-pressure axial flow fans.

关 键 词：轴流风机 非均匀间隙 非均匀度 泄漏涡 数值模拟 

分 类 号：TK431[动力工程及工程热物理—动力机械及工程]