民用大涵道比涡扇发动机风扇机匣声衬设计

为了研究民用大涵道比涡扇发动机风扇机匣声衬的降噪效果,基于Wiener-Hopf管道声传播预测方法和声阻抗模型,形成了风扇机匣声衬设计流程和方法,对某民用大涵道比涡扇发动机风扇机匣开展声衬设计研究,包括风扇前和风扇/OGV之间两段声衬的设计。首先选择边线和飞越两个适航工况的管道可传播声模态作为降噪目标声源,以工程要求为设计边界,获得最优声阻抗和声衬结构参数,然后在真实流道形状下,对所设计声衬在目标声源和其他频带声源的消声量进行评估。结果表明,所设计的两段风扇机匣声衬在目标声源和低阶BPF其他声源处的消声量可观,达到声衬降噪的目的。

Fan Case Acoustic Liner Design of the High Bypass Ratio Turbofan Engine

In order to investigate the noise reduction effects of fan case acoustic liner of the high bypass ratio turbofan engine, the fan case acoustic liner design process are established based on Wiener-Hopf duct sound propagation method and perforate liner impedance model, researches were done for the purpose of fan case acoustic liner designing of a certain turbofan engine, including the acoustic liner near the leading edge of fan blade, and the acoustic liner between fan blade and OGV. Firstly, two acoustic modes were selected as the target source for acoustic liner designing, considering engineering design demand, the optimized impedance and acoustic liner structure parameter were calculated. Then the reduction loss of real duct was calculated. The results show that the IL of target source and certain BPF source was significant, both for the two segments of liner.