Abstract The impeller of squirrel cage fan exerts great effects on the internal flow fields and fan aerodynamic performance. On the premise of maintained impeller-volute tongue distance and production cost reduction, this paper proposes a blade trimming method focusing on axial modification of blade inlet in an attempt to improve the impeller flow condition and further the aerodynamic performance of squirrel cage fan, which is divided into blade full trimming and part trimming. Aerodynamic performance tests and numerical simulations are performed to explore the effect of blade trimming on the fan aerodynamic performance and the related flow mechanisms. The results show that the blade trimming with proper trimming parameter enables the fan to achieve higher fan aerodynamic performance in terms of total pressure efficiency and static pressure rise, between which full trimming is preferable to part trimming. With the optimum full trimming of blade, the axial distributions of mass flow at the impeller inlet and outlet become more uniform. The dimension of inactive zone near the front span is decreased. On the blade pressure surface, the forces are reduced with obvious improvement of gradients near the front span and back span. A better match between impeller and volute tongue is achieved as the decreases of reversed flow coefficients at the impeller inlet and outlet and recirculated flow coefficient in the volute.

中文翻译：

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叶片修整对鼠笼式风扇气动性能影响的实验与数值研究

摘要 鼠笼式风机叶轮对风机内部流场和气动性能有很大影响。在保持叶轮-蜗壳舌距和降低生产成本的前提下，提出一种以叶片进口轴向修正为重点的叶片修整方法，以期改善叶轮流动条件，进一步提高鼠笼风机的气动性能。分为刀片全修和部分修整。进行气动性能测试和数值模拟，以探索叶片修整对风扇气动性能的影响及相关流动机制。结果表明，适当的微调参数下的叶片微调使风机在全压效率和静压升方面获得更高的风机气动性能，在这两者之间，完全修剪比部分修剪更可取。通过优化的叶片全修整，叶轮入口和出口处质量流量的轴向分布变得更加均匀。前跨附近非活动区的尺寸减小。在叶片压力面上，受力减小，前跨和后跨附近梯度明显改善。随着叶轮进出口逆流系数和蜗壳内回流系数的降低，叶轮与蜗壳舌部的匹配度更好。在叶片压力面上，受力减小，前跨和后跨附近梯度明显改善。随着叶轮进出口逆流系数和蜗壳内回流系数的降低，叶轮与蜗壳舌部的匹配度更好。在叶片压力面上，受力减小，前跨和后跨附近梯度明显改善。随着叶轮进出口逆流系数和蜗壳内回流系数的降低，叶轮与蜗壳舌部的匹配度更好。