Application of phased array technique in the research of civil airplane airframe noise

Microphone phased array technique is one of the most important means of the airframe noise research. Microphone phased array technique was investigated to study the airfame noise in closed wind tunnels. An array optimization method was developed for the aeroacoustic measurement in closed wind tunnels, and the arrays for surveying high lift noise and landing gear noise are designed separately. Based on the phased array technique, the noise of scaled high lift device and landing gear of a civil airplane are surveyed in the closed wind tunnel. It can be concluded from the experiment results that the major noise sources are identified by the phased array technique and the efficiency of the noise reduction are verified.