飞行器仪器舱混响室声环境实验研究和数值模拟

Acoustic Environmental Experiment and Numerical Simulation of Apparatus Cabin of Aircraft in Reverberation Chamber

针对飞行器发射、飞行中的环境噪声问题,进行了飞行器的混响室噪声实验.在噪声实验过程中,以特定规范谱为声压级控制谱来调节混响室声场,使测量的噪声谱与控制谱接近,模拟飞行器的飞行环境进行了3次不同声压级的噪声实验,得到了实验件的内部声场和结构加速度响应.在实验的基础上,利用统计能量分析法对飞行器噪声实验进行了数值模拟.研究结果表明:在噪声实验中,飞行器内部的声场低于外部混响室的声场,但内、外最大声压差相差不大;结构的响应与结构刚度有关.数值模拟结果与实验数据的对比表明,统计能量分析方法在250 Hz以上的高频段模拟结果较好,而在250 Hz以下预示精度存在较大差别,说明利用统计能量分析方法进行中高频段噪声环境预示是可行的.

Focusing on flight environmental noise issues for aircraft, three experiments of different sound pressure levels were conducted in the reverberation chamber, where the specific acoustic power spectrum was utilized as the reference spectrum and the reverberant sound spectrum was adjusted to make the response spectrum in accordance with the reference spectrum. The acoustic environment of aircraft was simulated and structure responses were obtained. Numerical simulation for aircraft environmental noise test was performed with the statistical energy analysis method on the basis of the experimental data. The results show that for aircraft subjected to external acoustic excitations, the internal sound field gets lower than the external sound field, but the maximum sound level difference between the internal and external sound fields changes slightly. The structure response is related to structure stiffness. Comparing the numerical simulation results and the experimental data, the model simulation by the statistical energy analysis coincides well with the experimental results above 250 Hz, but the accuracy gets worse below 250 Hz. So the acoustic environment prediction by the statistical energy analysis is feasible within the middle and higher frequency range.