前弯动叶片变工况性能的估计方法

在低速轴流风机中, 前弯动叶和常规径向直叶片比较, 具有提高效率 4～5%,增加变工况范围 15～ 20%的优良性能。本文在发展完善“双激盘”理论模型的基础上, 采用平板圆弧叶型实验数据, 加入了攻角损失的计算, 并将其用于前弯动叶片设计工况以及变工况的性能估计。在设计工况下和实验结果比较, 沿叶高效率的最大误差为 1.5%,沿叶高总压的最大误差为 1.8%,两参数沿叶高的流量平均误差分别为 1%和 1 .5%。在稳定工况范围内按流量平均计算的效率误差和总压误差均在 2%以内。计算结果表明, 该法可用于估计变工况下弯掠动叶片的性能, 是一种简单、明了、适合工程需求的方法。 

A Modified Estimation Method for off-Design Performance Prediction of Forward Skewed Rotor Blades

The forward skewed rotor blade of low speed axial flow fan can increase the efficiency by 4～5%,expand the range of off design condition by 15～20% in the comparison with the typical blade straight blade.In this paper,the “di actuator disc”theory model is applied to calculating the flow field of forward skewed rotor blade;the modified loss model in design condition is adapted to the lift/draft model of attack angle and is used to estimate the off design condition flow field,the efficiency of the blade,etc.The estimated results at the design condition are in good agreement with the experimental results [1] .The maximum error of the efficiency along the blade height is 1.5% and that of the total pressure is 1.8%.The mass average errors are 1% and 1.5%.At off design condition,the mass average errors of the efficiency and the total pressure are all less than 2%.It is proved that this method is applicable and can meet the need of the engineering design.