用遥测数据识别飞行外声场

给出了一种用遥测数据通过混响室噪声试验识别飞行外声场的方法,并提供了一个实例。该方法以遥测加速度功率谱为控制谱,以遥测点为响应测量点,通过噪声试验调节外声场声谱,使测量点的响应与控制谱一致,识别出飞行外声场。共识别了起飞段和跨音速段两种外声场。实例给出了某火箭某次遥测数据及识别外声场,并将识别外声场与该火箭另次飞行的实测外声场进行了比较。比较表明,识别外声场与实测外声场总声压级最大相差5.2dB,谱型振动能量分布存在较大差别。作为有限条件下(仅有遥测数据)获取外声场的一种方法,并以此外声场作为输入载荷对试件进行故障分析和振动环境获取,从飞行结果看,该方法是可行有效的。

Prediction of flight outer sound field by flight telemeasured dada

A method of predicting the flight outer sound field according to flight accelerate auto-power spectrum by means of reverberant acoustic test,and an example,are given.The method is to utilize the accelerate auto-power spectrum as the reference spectrum,and telemeasuring point as the response point,adjust the reverberant sound spectrum in a reverberant acoustic test,make the response spectrum in accordance with the reference one,and the reverberant sound field at this moment is just the predicted flight outer sound field.The sound fields of lift-off and transonic region are respectively predicted.In the example,both the flight data and predicted outer sound field are presented,and the predicted outer sound fields are compared with the in-service sound fields obtained in the next flight.It shows that the maximum difference of overall sound pressure level is 5.2dB,and a relative large difference between the spectrum does exist as well.