空腔噪声测量技术探讨

Discussion of Measurement Technique for Cavity Noise

空腔流动现象广泛存在于飞机的飞行过程中,由其引起的强烈气动噪声会显著地降低腔内航空构件的寿命,并且破坏电子元件的灵敏度。首先介绍空腔诱发气动噪声的机理、空腔内部的流场类型及噪声分布情况。鉴于实际飞行过程中空腔周围边界条件与计算机仿真、风洞试验中的差异,飞行试验是获得飞机在飞行环境下空腔内声场和压力场分布的唯一途径。参考国内、外空腔声场和流场的风洞测量经验,提出飞行试验中的空腔噪声的测量方法与数据处理方法,并完成脉动压力传感器与表面传声器的对比试验,验证此测量方法的可行性。

Cavity flow phenomena occur very often during the aircraft flight.The very high noise generated by the airflow reduces the life of surrounding structural components and damages the sensitivity of surrounding electronic components.Because of the boundary condition differences among practical flight,computational simulation and wind tunnel test,flight test is the unique method to measure the distribution characteristic of sound field and pressure field in cavity of aircraft in flight.This paper introduced the generation mechanism of air-flow noise,flow types and the noise distribution in the cavity.Then,according to the measurement experiences from wind tunnel tests inland and overseas,the measurement method and data processing method for cavity noise in flight test were presented,and the feasibility of this method was verified by comparison of the test data from fluctuating pressure transducer and surface microphone.