风扇出口导向叶片低噪声设计Ⅰ：方法与优化

Low noise design of fan outlet guide vane,part Ⅰ:Method and optimization

作为“风扇出口导向叶片(Outlet Guide Vanes,OGV)低噪声设计”系列文章的第1篇,本文在现有压气机气动设计流程的基础上,加入了噪声评估过程,建立了基于通流设计的气动/声学一体化设计方法。为提高设计阶段的评估速度,以三维升力面理论与管道声学理论为基础,从通流设计和造型设计输出中提取参数,结合转子尾迹模型,建立了转/静干涉噪声的解析预测模型。以现代大涵道比涡扇发动机风扇/增压级为对象,采用该模型系统分析了OGV轴向掠形与周向倾斜对转/静干涉噪声的影响,获取了轴向掠形角与周向倾斜角等三维设计参数与风扇噪声的关系图谱,初步确定了低噪声设计较优降噪量的掠和倾组合方案。以此为基础,在保持叶尖子午投影位置和弦长不变的前提下,将叶片前缘和径向积叠进行参数化,采用遗传算法进一步开展了OGV的低噪声优化设计,最终获得了2个优化方案,预估的降噪量达到了8dB。

As the first part of the"Low noise design of fan outlet guide vane"serial articles,this paper proposes an integrated aerodynamic and acoustic design method.The influence of axial sweep and circumferential lean of Outlet Guide Vane(OGV)on the rotor wake/stator interaction noise of a modern high-bypass ratio fan stage is investigated.To improve the evaluation efficiency in the design process,an analytic model for the rotor/stator interaction noise is employed based on the three dimensional lifting surface and duct acoustic theories.A rotor wake model whose parameters are obtained from throughflow calculation and blade design steps is also applied.The rotor/stator interaction noises of different combinations of sweep and lean angles are examined to obtain the effect graph,which is used to choose a prime combination of sweep and lean angles as the starting point of the following optimization.During the optimization,the chord length and blade tip meridian position are fixed,and a genetic algorithm is employed to obtain the final leading edge and stack line shape of OGV.The two obtained swept and leaned vanes can gain a promising reduction of interaction noise at least of 8 dB.