带弹性障板充液管路管口的声辐射特性

The characteristics of sound radiated from the opening of a fluid-filled pipe baffled with an elastic plate

建立了末端带有弹性障板的有限长直管道的声固耦合有限元模型,分析了声激励下管与流体、弹性板与流体、以及管板整体与流体三种耦合工况下管口声能量响应以及声阻抗的变化。结果表明:声激励下,耦合系统辐射声能量在大部分频段内以管口流体声占主导;末端弹性障板的存在会显著影响管口的辐射声功率响应,特别是板的周向对称模态对声功率响应的峰谷影响很大;而管与管内流体的耦合使得弹性障板低频段辐射声功率有一定提升。可见,管口流体声阻抗响应与其声功率响应具有一致的变化规律。

The vibro-acoustic characteristics of a finite pipe baffled with an elastic plate were investigated under the consideration of the fluid which interacts both with the pipe and the circular plate.The coupled system model of structure and sound were established based on the Finite Element Method(FEM).Concentrating on the sound energy and radiation impedance of the opening of the pipe system under the acoustic excitation of a plane wave,different coupled conditions were analyzed respectively,which are the pipe fixed,the plate fixed and the full coupled condition.The results showed that:the sound power is predominantly radiated by the fluid rather that the structure under the acoustic excitation in the low frequencies we concerned;the vibration of the elastic plate has effectively influenced the sound power and the radiation impedance response of the coupled system although the sound energy radiated is much less than the fluid,further study indicated that the symmetric bending mode has a remarkable effect on the peak frequencies of the sound power response;and the interaction of the pipe and the internal fluid has enhanced the sound energy transmitted from fluid to the elastic plate.The responses of the radiation impedance have coincidence peak frequencies with the responses of the sound power.