This study focuses on advanced testing techniques in the acoustic field of aviation mechanical equipment, specifically addressing the fan noise issue of turbofan engines in civil aircraft. By applying cyclostationary modeling, the study uncovers the periodic mechanisms behind fan broadband noise, contributing to a better understanding and control of rotating aerodynamic noise sources. An independently developed, world-class duct acoustic mode excitation device, combined with a full-frequency acoustic synthetic aperture asynchronous measurement method, enables precise identification of complex modal distributions in the high-frequency range of compressors. This significantly enhances the accuracy of sound source propagation characteristic measurements. Furthermore, the study introduces a full-frequency acoustic imaging technology tailored for rotor aerodynamic noise imaging in environments with significant interference. This technology provides detailed experimental data to support noise assessment and noise reduction design. Overall, the cyclostationary modeling reveals the hidden periodic features of fan noise, the duct acoustic mode identification technology offers a precise new approach for aviation acoustic experiments, and the full-frequency acoustic imaging technology facilitates accurate localization and evaluation of noise sources.

Liang Yu is a full professor at Northwestern Polytechnical University. Prof. Yu has authored nearly 200 publications in the domain of "Acoustic Perception and Intelligent Information Processing in Mechanical Equipment," with a significant portion published in esteemed international SCI journals, including MSSP, JSV, and TIM. Throughout his career, he has successfully led three projects funded by the National Natural Science Foundation of China (NSFC) and over 20 projects sponsored by provincial, ministerial, and industrial entities. Prof. Yu plays an active role in the international academic community, serving as a member of the organizing committees for four prestigious international conferences: ICICSP, MEAE, ICMIE, and MAES. He has also been honored with the position of conference chair for the 2024 International Conference on Mechanical Engineering and Aerospace Engineering. His expertise and insights have been showcased through invited plenary speeches at two international conferences. Furthermore, Prof. Yu maintains a strong presence in the academic publishing sphere, serving as a reviewer for 34 domestic and international journals and as a guest editor for four special issues.