声辐射阻抗传感器元件设计与声阻抗测量实验研究

Research on Design of the Resistance Probe and Experiments Using the Probe

声辐射抗阻是声优化设计中的关键设计变量,但目前尚未有成熟商用传感器面市,各种测量方法皆处于实验室研究阶段,文中根据前期研究所得的用可测量——声压表达的声辐射阻抗计算公式,选择了实验中用以近似点声源腔的扬声器和测量结构表面及扬声器内声压的声压传感器.设计了声辐射阻抗传感器,选取了信号采集设备并搭建了实验系统,用该套测量系统测量了无限大障板上圆形活塞的声辐射阻抗,对比了无限大障板上圆形活塞自点表面声阻实验值和解析解,结果表明在1～3kHz频段实验值和解析解非常接近,通过进一步改进低频段的性能后,可使用该装置对复杂结构表面辐射声阻进行测量.

According to our prior research, sound radiation resistance expression has been derived with measurable sound pressures. In this paper, sound radiation resistance is studied by experimental re- search. A small loudspeaker is selected to approximate a point simple source, two microphones are choosed to measure surface sound pressure and the sound pressure of loudspeaker cavity separately. A sound radiation resistance probe is designed and signal acquisition device is selected. Then a measure- ment system is set up. The probe and the measurement system are used to measure the sound radia- tion resistance of baffled circular piston. Analytical and experimental radiation resistance curve as a function of frequency are compared. The results show that the analytical and experimental predictions for the resistance are in close agreement between 1 kHz and 3 kHz. Thus the resistance probe can be used to predict radiation resistance of geometrically complex boundary surfaces.