分布式波浪前缘静子叶片对单级轴流风扇单音噪声影响的数值研究

Numerical Study on Tonal Noise Reduction of Single Axial Fan with Distributed Wavy Leading-Edge Stator

关键词:  波浪前缘叶片  单音噪声  声类比理论  风扇  FW-H方程  混合模型

Key words:  Wavy leading-edge blade  Tonal noise  Acoustic analogy  Fan  FW-H equations  Hybrid method

摘要:

为了适应逐年严苛的适航噪声标准，改善飞机噪声环境，突破航空发动机降噪技术的瓶颈，有必要开发新的降噪手段以指导叶轮机械降噪设计。采用URANS与FW-H方程混合方法，通过将波浪前缘构型运用在叶片流动损失较大、声源强度较强的部分后，进一步观察其气动性能和降噪效果。研究表明：与基准叶片相比，分布式波浪前缘静子叶片可以在1BPF（Blade Passing Frequency）时降低风扇入口声功率级0.67~1.9dB，2BPF时降低风扇入口声功率级1.87~4.18dB，3BPF时降低风扇入口声功率级2.4~6.8dB，同时，总压比最高提升0.027%，等熵效率最高提升0.28%。因此，分布式波浪前缘静子叶片在叶轮机械降噪方面有很好的运用前景。

Abstract:

In order to adapt to the severe airworthiness noise standards， improve the aircraft noise environment， and break through the bottleneck on noise reduction technology of aircraft engines， it is necessary to develop new noise reduction methods to guide the turbomachinery noise reduction design. The aerodynamic performance and noise reduction effectiveness by applying wavy leading-edge to the part with larger flow loss and higher sound source intensity with the hybrid method of URANS and FW-H equation were studied. The results show that， compared with base blade， the fan inlet sound power level could be reduced about 0.67~1.9dB at 1BPF， 1.87~4.18dB at 2BPF and 2.4~6.8dB at 3BPF， respectively， by using those distributed wavy leading-edge stators. Meanwhile， total pressure ratio and isentropic efficiency increase up to about 0.027%， 0.28%， respectively. Therefore， the distributed wavy leading-edge stator has a good application prospect in the turbomachinery noise reduction.