飞机座舱结构声的弹性波主动控制研究

研究通过控制飞机座舱结构振动的弹性波的传播来减少由振动产生的辐射噪声的方法。制作了飞机座舱原理性模型，分析了外界气动力作用下弹性振动传播的主要路径，确定了压电元件的布置方案。利用弹性波控制的基本思想，采用IIR自适应滤波嚣识别被控通道的特性，实现对座舱结构振动的前馈控制，以抑制其辐射噪声．进行了不同单频激励下的振动和噪声控制试验，并测量了控制前后的振动和噪声。结果表明，控制后振动和噪声衰战了10dB以上。

Structural Noise Suppression of Aircraft Cabin Using Elastic Wave Control Concept

A method is investigated for structural noise reduction of aircraft cabin by elastic wave control concept. An aircraft cabin model is made and the elastic wave propagating paths are analyzed while the air is exciting upon the cabin structures. The functional elements are located to the model. Based on the concept of elastic wave control, a strategy for structural borne noise suppression is put forward. By employing piezo elements, the structural noises are suppressed by attenuating its vibrations, while the vibrations are abated by controlling the propagation of the elastic waves. An IIR adaptive filtering feed forward algorithm is derived and a simplified filtered U LMS updating algorithm is developed in C language. Experiments are carried out for validation of the method under different sinusoid exciting, and the vibrations and the noises of cabin are reduced by more than 10 dB.