一种有效的消波装置

 对无限长渠道中小振幅入射波通过两块间距为ｌ,透水性能不同的多孔透水板的反射和透射进行了研究。应用分离变量法得到了反射波和透射波的波形。结果表明,当ｌ为入射波半波长的倍数时,反射波和透射波振幅最大,消波效果差,最佳消波率为５０％。当ｌ为入射波１／４波长加半波长的倍数时,反射波和透射波振幅最小,消波效果好,最佳消波率大于５０％。此外,还得到了无反射波的条件。

AN EFFECTIVE WAVE-DISSIPATION DEVICE

The reflection and transmission of small amplitude surface wave by two vertical po-rous plates with different penneabilities and spacing l fixed in the middle of an infinitely long channel of constant depth are studied.Analytical solutions in closed foims are obtained for the surface wave profiles.It is found that when the spacing l is a multiple of the half-wave length of the incident wave, both the reflected and transmitted wave amplitudes have the maximum values.In this case,the optimum wave-dissipation rate is less than 0.5. On the other hand,when the spacing l is a quarter-wavelength plus a multiple of the half-wavelength of the inci-dence wave, not only the reflected wave amplitude but also the transmitted wave amplitude re-duce to minima。In this case, the optimum wave-dissipation rate is greater than 0.5. Moreover,the condition related to non-reflected wave is obtained.