动叶可调轴流风机叶片切割前后的性能研究

摘要

The variable-pitch axial fan of OB-84 type with relative blade trimming quantity of 5%, 10% and 15%, installation angle of 29°, 32°and 35°is simulated by fluent.The performance cures are acquired and the effects of blade trimming quantity and installation angle on internal dynamics and operating performance are investi-gated.The results show that the fan full pressure and efficiency reduce with increasing blade trimming quantity at the same installation angle, and flow loss of tip clearance is deteriorated.Meanwhile, entropy production of the fan tends to be augmented with the increase of trimming quantity.The full pressure and efficiency augments with in-creasing installation angle at the same blade trimming quantity, and the corresponding flow rate to the maximum ef-ficiency moves to the direction of large flow rate.The formulas of operating points before and after blade trimming are presented and they provide a theoretical guidance for blade trimming in practice.%以OB-84型动叶可调式轴流风机为对象，采用Fluent软件对叶片安装角为29°、32°和35°在5％、10％和15％切割量时的风机进行了三维数值模拟，得到了不同情形下的风机性能曲线，分析了安装角和切割量对风机性能和内流特性的影响。结果表明：在同一安装角下，风机全压和效率随切割量增大而减小、且叶顶流动损失变大，整机熵产增加；在同一切割量下，全压随安装角增加而提高，效率最高值向大流量侧移动；所得叶片切割前后运行工况点的关系式可为叶片实际切割提供理论依据。