轴流风扇两种扭叶片设计方法及其气动性能的比较Comparison on Aerodynamic Performance of Twisted Blades Designed by Two Approaches for Axial Fan
王企鲲,陈康民
WANG Qi-kun,CHEN Kang-min (University of Shanghai for Science and Technology
摘要(Abstract):
"等密流型"与"变密流型"设计方法是轴流风扇扭叶片气动设计中的两种典型的方法,本文对这两种气动设计方法进行了深入的探讨,并以某型轴流风扇为例,分别采用这两种方法对其进行了扭叶片改型设计,详细比较了按这两种扭叶片设计方法所获得的扭叶片的几何特征。在此基础上,利用CFD技术数值研究了这两种扭叶片的气动性能在设计工况与变工况的差异,以此对这两种方法的设计效果作出评价。研究结果表明:"变密流型"扭叶片的气动性能受变环量指数影响较大,较大的变环量指数能明显地提高"变密流型"扭叶片的气动性能,而"等密流型"扭叶片的气动性能受变环量指数的影响较小;"变密流型"扭叶片具有较大的径向压力梯度,易于诱发径向串流而引起额外的二次流损失,这直接造成其静压效率明显低于相应的"等密流型"扭叶片;按"等密流型"方法设计的扭叶片,其叶道根部具有较小的扩压度,这使其在小流量工况下叶根部抗失速能力明显高于对应的"变密流型"扭叶片。
There are two design approaches for the twisted blade of the axial fan,which are called "Constant Throughflow Velocity Approach" and "Variable Throughflow Velocity Approach" respectively.Detailed discussions about these two approaches are presented.As an example,two twisted blades are respectively designed and their geometric characteristics are detailed compared.CFD technique is introduced to investigate the difference of the aerodynamic performance for these two twisted blades so as to obtain pertinent evaluation on these two design approaches.Results indicate that the aerodynamic performance of the twisted blade designed by "Variable Throughflow Velocity Approach" may be influenced more obviously by the twisted power than that of the opposite twisted blade and the larger twisted power may enhance its aerodynamic performance;There is larger radial gradient of the pressure on the twisted blade designed by "Variable Throughflow Velocity Approach",resulting in secondary flow loss,which is the reason why its static pressure efficiency is lower than that of the opposite twisted blade;There is less pressure dilation at the heel of the blade on the twisted blade designed by "Constant Throughflow Velocity Approach",which improves larger ability to resist the stalling than that of the opposite twisted blade.
关键词(KeyWords):
扭叶片;气动性能;轴流风扇;CFD数值研究
twisted blade;aerodynamic;performance;axial fan;CFD technique
基金项目(Foundation): 上海理工大学博士启动经费(200910)
作者(Author):
王企鲲,陈康民
WANG Qi-kun,CHEN Kang-min (University of Shanghai for Science and Technology
参考文献(References):
- [1]李庆宜.通风机[M].北京,机械工业出版社,1982.
- [2]王企鲲,陈康民.微型轴流风扇中变环量指数对扭叶片气动性能的影响特点[J].机械工程学报,2009,45(4):76-82.
- [3]王企鲲.微型轴流风扇气动设计及其相似性研究[D].上海理工大学,2008.
- [4]HIRCH.Numeca’s flowintegrated environment for tur-bomachinery and internal flows?User manual[M].Belgium:NUMECA International,2003.
- [5]徐建中.叶轮机械气动热力学的回顾与展望[J].西安交通大学学报,2000,22(6):40-48.