Review of acoustic wind tunnel testing and analysis methods for helicopter rotors

Acoustic wind tunnel testing and analysis methods for helicopter rotors provide an essential technical basis for investigating rotor aerodynamic noise generation mechanisms and low-noise design. These methods primarily cover two areas: rotor aeroacoustic wind tunnel testing and aeroacoustic signal processing. Wind tunnel testing is used to acquire rotor aerodynamic noise and related experimental data, whereas signal processing is used for acoustic signal feature extraction, identification and separation of noise components, and noise mechanism analysis. In this paper, acoustic wind tunnel testing and analysis methods for helicopter rotors are reviewed. The current status of aeroacoustic wind tunnel testing techniques for helicopter rotors is outlined, and recent advances in signal processing and analysis methods for rotor aerodynamic noise are summarized. Particular emphasis is placed on cyclostationary signal processing methods and their applications in rotor aerodynamic noise analysis. The main challenges and future development trends in this field are also discussed.