长短复合导叶对两级动叶可调轴流风机性能的影响

Influence of Long-short Composite Guide Vanes on Performance of Two-stage Variable-pitch Axial Fan

为研究长短复合导叶对动叶可调轴流风机性能的影响,以某大型两级动叶可调轴流风机为对象,构建了第二级导叶后部和前部长分别依次缩短10%等10种长短复合导叶方案,采用FLUENT软件对不同方案下的轴流风机进行了三维定常数值模拟,分析了复合导叶对风机性能、内流特征和静力结构的影响。研究表明:长短复合导叶对轴流风机的性能有显著影响,在中小流量侧导叶后部缩短10%和20%方案气动性能得到提升,在大流量侧则与之相反;其他缩短方案其性能均低于原风机,导叶后部缩短风机性能优于导叶前部缩短情形;在设计工况下,导叶后部缩短10%时第二级动叶表面压力发生变化、做功能力增强,整机熵产率有所增加,第二级动叶应力和总变形有所增大,振动减弱,但满足使用要求。

In order to investigate the influence of the long-short composite guide vanes on the performance of variable-pitch axial fans,10 schemes of composite guide vanes were established by reducing the leading or trailing length of second-stage guide vane by 10%-50%,respectively with a large two-stage variable-pitch axial fan,the 3 D steady simulation of the axial fan was conducted under different schemes,and the aerodynamic performance,internal flow characteristics and static structure were analyzed.The results show that the long-short composite guide vanes have a significant impact on the performance of the axial fan;the aerodynamic performance of the schemes with 10% and 20% reduction of trailing length of the composite guide vanes was improved at medium and small flowrate,and manifested the opposite variations at large flowrate;fan performance under other reduction schemes was inferior to the original fan,and the performance of fans with reduced trailing length of the guide vanes was superior to the performance of the guide vanes with reduced leading length;the pressure on the surface of the second-stage variable-pitch vanes of the fan varied when the trailing length was reduced by 10%,the work doing capability was enhanced,and the entropy production rate of the whole fan was increased somewhat under design condition.The stress and the total deformation of the secondstage variable-pitch vanes were increased somewhat and the vibration was weakened somewhat under design condition,but it still meets the operation requirements.