空腔尖劈结构吸声性能的实验研究

对尖劈结构的吸声性能进行了实验测试,进而研究了含空腔尖劈吸声结构的吸声性能。根据变截面波导理论建立的吸声系数方程,计算了尖劈结构的吸声系数,讨论了尖劈结构吸声性能随频率、静水压力及空腔结构的变化规律,并将计算值与实验值进行了对比。研究结果表明:随着静水压力的增大,尖劈结构吸声系数曲线的形状基本不变,但其数值有所下降;同种材料不同空腔类型尖劈结构的吸声性能差别较大,在低频段尤为明显,而对于同种腔型尖劈结构,其吸声性能则主要由空腔尺寸决定;对于含空腔尖劈吸声结构,增大空腔尺寸可以使尖劈空腔共振加强而提高其低频吸声效果,但空腔尺寸过大反而会影响尖劈结构的整体吸声效果,这对水下尖劈吸声结构的设计及其在实艇减振降噪中的应用具有一定的参考意义。

Experimental Research on Sound-Absorption Performance of the Wedge Structure with Cavity

The sound-absorption performance of wedge structure as well as that with cavity was tested by experiment.According to the sound-absorption equations obtained from the non-uniform waveguide theo-ry,the sound-absorption coefficient of wedge structure was calculated and the variation of performance with frequency,hydrostatic pressure and cavity structure was discussed.The calculated results were then compared with the experimental results.It shows that with the increase of water depth,the shape of sound-absorption coefficient curve does not change significantly under hydrostatic pressure,while the larger the hydrostatic pressure is,the greater the wedge sound-absorption coefficient drops down.Sound-absorption performance of the wedge made by the same material with different types of cavity varies sig-nificantly,especially in the low frequency range.As for the wedge with same type of cavity,its sound-absorption performance is mainly determined by the size of cavity.Thus,the low frequency sound-ab-sorption performance of the wedge structure with cavity can be greatly improved with the increase of cav-ity size,but the overall sound-absorption effect will be weakened if the cavity size is excessively large.These provide reference for the design of underwater wedge structure and the application of the wedge structure to the vibration and noise reduction of ship structure.