Feasibility of measuring noise sources on a detailed nose landing gear at low cost development

Abstract 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.