抑制风噪装置的实验

本文基于风噪原理提出了一种抗风噪结构设计,来抑制传声器拾取风噪。该设计由渐变管道和填充泡棉的腔体两部分组成。渐变管道用来降低气流流速,填充泡棉的腔体用来充当声屏障。COMSOL有限元仿真验证了渐变管道降低流速的能力,风噪实验证明了该设计能有效地抑制风噪。讨论了关键因素对该结构抗风噪能力的影响：大的腔体,小的渐变管道等效直径和高的泡棉密度,都有利于抗风噪效果。最后,基于声传输线和等效电路理论,建立了声波经过该抗风噪结构的传递损失模型。基于该模型和高频不失真条件,提出了抗风噪结构的尺寸设计指标。

Experiment on a structure for suppressing the wind noise

Based on the principle of the wind noise, an anti-wind noise structure design is proposed to suppress the wind noise picked up by the microphone. The design consists of a gradient pipe and a cavity filled with foam. The gradient pipe is used to reduce the speed of the air flow, and the cavity filled with foam is used as a sound barrier. COMSOL simulation verifies the ability of gradient pipeline reducing velocity, and experiments show that the designed structure can effectively suppress the wind noise. Besides, the influence factors are discussed: large cavity, small pipe diameter and high foam density are helpful to the anti-wind noise performance. Finally, based on the sound transmission line and equivalent circuit theory, the transmission loss model of sound wave passing through the structure is established. Based on the model and the condition of high frequency distortion, the size requirements of the structure are proposed.