磁致伸缩换能器辐射板形状对声场分布的影响

磁致伸缩换能器可作为热声制冷机的声源装置,辐射板的形状直接影响声压输出效率,从而影响制冷效果。为提高换能器工作效率、减小换能器体积,辐射板需在Terfenol-D棒的激励下产生大振幅、高频率的活塞振型。针对这一问题,应用ATILA软件分析了磁致伸缩换能器辐射板形状对谐振腔振动幅频特性的影响以及对谐振腔内声场分布的影响。结果表明:相同激励条件下,凹球面辐射板出现活塞振型时振幅最大,对应谐振腔中声压幅值最高;谐振腔端面形状为凹球面时,具有聚焦声压幅值的作用;端面形状为凹发射端-凸反射端组合的谐振腔内声压幅值最高。以上结论为合理设计辐射板、谐振腔两端面组合形状提供了参考。

The influence of the shape on radiation sound field distribution of the magnetostrictive transducer

Magnetostrictive transducer can be used as a source device for thermoacoustic refrigerator, the shape of the radiation plate directly affects pressure output efficiency, thus affects the cooling effect. In order to improve the working efficiency and reduce the volume of the transducer, the vibration mode of the large amplitude and high frequency of the radiation plate is generated by the excitation of the Terfenol-D bar. To solve this problem, in this paper, the influence of the shape on the characteristics of vibration amplitude frequency and the acoustic field distribution of the resonant cavity of the magnetostrictive transducer is analyzes by using ATILA software.Results show that: under the same excitation conditions, the amplitude concave spherical radiation board is at maximum piston modes, corresponding to the maximum amplitude of the sound pressure cavity. Cavity facet is concave spherical shape, having a focusing effect sound pressure amplitude. The resonator acoustic pressure amplitude of end shapes with concave transmitting end - convex reflector end is highest. These conclusions provide a reference for as reasonable designing radiating plate and end combinations form of resonator cavity.