叶片不同弯折角对高速斜流风机气动性能的影响

叶片弯折角作为风机的重要设计参数，能否合理选择弯折角对风机整体性能影响明显。针对8°、18°、28°、38°、48°5种不同叶型弯折角进行CFD数值模拟，研究表明：弯折角增大，最高效率点向大流量工况偏移；当弯折角超过一定值后，流道扩压度过大，小流量工况流动分离明显，压力迅速下降，风机高效区范围变窄。弯折角变化对效率影响不大，但弯折角变小则压力降低。内部流场分析表明，弯折角过小将不利于叶片加载，弯折角过大则有利于高效工况区间的拓宽。

Influence of Different Blade Bending Angles on Aerodynamic Performance of High Speed Diagonal Fan

Blade bending angle is an important design parameter of the fan. Whether the blade bending angle can be reasonably selected has obvious influence on the overall performance of the fan.The results of CFD numerical simulation for five different blade profile bending angles of 8°, 18°,28°, 38° and 48° show that the maximum efficiency point shifts to the larger flow condition when the bending angle increases. When the bending angle exceeds a certain value, the flow passage expands too much, the flow separation is obvious in the condition of low flow rate, the pressure drops rapidly,and the range of the high efficiency zone of the fan becomes narrow. The bending angle has little effect on efficiency, but the pressure decreases when the bending angle decreases. The internal flow field analysis shows that too small bending angle is not conducive to blade loading, and too large bending angle is conducive to the widening of the efficient operating range.