This work aimed to develop an aeroacoustics analysis of a nose landing gear through rational and low-cost wind tunnel tests to develop potential noise mitigation technologies of aircraft components. This approach led to using a nose landing gear model of the Boeing 777 aircraft, whose more complex parts were 3D-printed. The aeroacoustics and aerodynamics tests were performed in a hard-wall wind tunnel with the capability to perform aeroacoustics tests after corner-vanes and fan section treatment to reduce background noise. Improved beamforming techniques were applied for noise source localization through microphone array measurements. Also, near field noise analysis was performed by microphones installed inside model cavities as part of the correlation procedures for noise investigation and creation of reference data for further CAA simulations. Additionally, using wake-flow mapping and lateral aeroacoustics measurements allowed the characterization of the flow field and noise source positions at low subsonic speeds in the approach condition. The flexibility of the model construction allowed a systematic assembly of the main parts and structures, and therefore, a noise build-up analysis showed the contribution of each component to the overall noise of the nose landing gear. Near-field measurements provided better insights into the noise generation mechanisms of each component. Despite some limitations identified by following this approach, the results were consistent and revealed that the noise sources are concentrated in the bay cavity, at the upper structure, and between the wheels. The feasibility of measuring noise sources on a detailed nose landing gear has been achieved with relatively low-cost development, providing useful data for further CAA computations as well as noise mitigation development.

这项工作旨在通过合理和低成本的风洞测试对前起落架进行气动声学分析，以开发飞机部件的潜在降噪技术。这种方法导致使用波音 777 飞机的前起落架模型，其更复杂的部件是 3D 打印的。气动声学和空气动力学测试在硬壁风洞中进行，能够在角叶片和风扇部分处理后进行气动声学测试，以降低背景噪音。改进的波束成形技术通过麦克风阵列测量应用于噪声源定位。此外，近场噪声分析由安装在模型腔内的麦克风进行，作为噪声调查和创建参考数据的相关程序的一部分，以供进一步 CAA 模拟。此外，使用尾流映射和横向气动声学测量允许在进场条件下表征低亚音速下的流场和噪声源位置。模型结构的灵活性允许主要部件和结构的系统组装，因此，噪声累积分析显示了每个组件对前起落架整体噪声的贡献。近场测量可以更好地了解每个组件的噪声生成机制。尽管遵循这种方法确定了一些局限性，但结果是一致的，并且表明噪声源集中在舱腔、上部结构和车轮之间。