跨音弯掠风扇转子叶片的气动弹性剪裁

跨音风扇进口级增压比的进一步提高，主要受两方面的制约，一是效率，二是气动弹性失稳。这两个因素与转子流场中的激波和激波诱导的大尺度分离紧密相关。激波结构又和转子叶片前缘空间曲线形状直接联系。因此，如何精心设计转子叶片前缘空间曲线形状来控制激波结构，就成了当代风扇气动力学的前沿，并导致风扇弯掠空气动力学概念的出现。在具体设计中，此问题可称之为气动与气动弹性综合剪裁。本文简述综合剪裁中的一个组成部分，即气动弹性剪裁问题，并对一个单级风扇转子叶片给出实例。

AEROELASTIC TAILORING FOR ROTOR BLADES OF TRANSONIC SWEPT FANS

In order to raise the fan stage pressure,as an important measure to enhance engines thrust/weight ratio,there are two restrictive factors:First of all,the increase of rotor tip wheel speed will strengthen the shock waves in rotor passages,which decrease the efficiency.Then the strengthened shock waves could induce the onset of stall flutter.For the turbofans with small bypass ratio,the stall flutter is the main type of aeroelastic instabilities in the transonic fans.Both the above-mentioned two restrictive factors for raisng the stage pressure ratio are correlated closely with 3D shock wave structure and the largescale separation zone induced mainly by 3D interaction of the shock wave with boundary layer.However,the 3D shock wave structure inside rotor passages is correlated with the spatial curve of rotor blade leading edge closely.So,how to design the spatial curve of blade leading edge becomes an important frontier problem of the turbomachinery aerodynamics.During designing process of some modern transonic swept fans,a kind of integrated aerodynamic/aeroelastic tailoring program has been used.The aeroelastic tailoring,a main part of the integrated tailoring,is described,and an example has been shown in this paper.