对当前跨音风扇气动设计体系中损失系数和堵塞系数的关联分析

现有设计体系中对于损失系数主要是由实验和经验来确定。通流气动设计需计入叶片槽道内的附面层堵塞,反映附面层堵塞影响的堵塞系数也是依经验给定。本文对多台风扇设计进行分析后,发现现有的设计体系中损失系数和附面层堵塞系数之间彼此孤立,且不够协调,而事实上,两者是紧密相关的,体现在物理上就是损失和开式分离流之间的关系。本文在分析现有设计体系模型的基础上,提出了一个新的工程模型,把两者关联了起来,并给出了算例分析,且从算例结果中可以看到现有设计体系中单转子效率远大于级效率的原因之一。 

CONNECTION BETWEEN LOSS COEFFICIENT AND BLOCK COEFFICIENT USED IN TRANSONIC FAN DESIGN

Loss coefficient and block coefficient are interrelated in fact and the relation between them represents the relation between loss and separation.An engineering model is established to connect them,based on an analysis of many fan designs.The model determines the block coefficient from the loss coefficient,because the block coefficient derived from test loss coefficient is more believable than that from experience.At the same time,a computation test of a transonic fan is given as an example to verify the feasibility of the model.A conclusion has been drawn from the computation results that this model can estimate exactly the block coefficient and flow direction at the trail edge of rotor so as to improve the situation of the stator.It also explains why the rotor efficiency is superior to the stage efficiency.