弯扭联合成型叶片控制二次流

国内外许多学者在设法控制二次流,减小二次流损失这一研究领域进行了卓有成效的工作,其中采用收敛型通道抑制二次流和采用可控涡设计减小二次流损失的技术措施在生产型发动机上均得到了成功的应用。60年代初,苏联的杰依奇教授和本文作者王仲奇教授,为了改善端壁附面层状况和改变沿叶片表面径向压力梯度,以便抑制流体的传输作用,研究了倾斜叶片并提出了弯扭联合成型叶片的设想。目前,它已在许多先进的航空发动机上得到了成功的应用。本文扼要地分析了这种叶片控制二次流的机理,并介绍了它的环形叶栅的实验结果。通过对一小型涡喷发动机涡轮导向器三元气动改型设计的算例分析,说明应用弯扭联合成型叶片是提高发动机性能的一个有效手段。 

APPLICATION OF COMPOUND LEANED BLADES TO CONTROLLING SECONDARY FLOW

Mechanism of controlling secondary flow by using positive leaned blades or compound leaned blades is considered in this paper.The conclusion is that the positive leaned blades produce a converse radial pressure gradient at the hub.Under its action the low energy fluid in the blade surface boundary layer is migrated from hub to midspan,the blade to blade transverse pressure gradient is reduced,passage vortices is weakened and hence the secondary flow losses are decreased.A computation of the compound leaned blades applied to guide vanes in a small engine has been performed as an example.Its results show that by comparison with conventional blades,the degree of reaction and static pressure at the hub of the compound leaned blades are increased,the flow behavior near the hub of working blades is improved;the degree of reaction at the tip is reduced and therefore the leakage losses are cut down too.It is proved that the positive leaned or the compound leaned blades are applicable to controlling the spanwise pressure gradient,the stage reaction and the downstream effect of the secondary flow.