海底沉积物声波现场测试和有限差分数值模拟研究  

Measurement of marine sediment and modeling acoustic wave with a finite-difference method

作　　者：王东[1] 张海澜[1] 陶春辉[2] 

机构地区：[1]中国科学院声学研究所,北京100080 [2]国家海洋局第二海洋研究所海底科学重点实验室,杭州310012

出　　处：《声学技术》2007年第1期15-20,共6页Technical Acoustics

摘　　要：利用基于Biot理论的高阶交错网格有限差分算法,模拟了声源在不同位置条件下激发声波的传播,重点讨论了纵波和各种转换波的声场,并与我国某海域地区海底沉积层的现场测试数据进行了对比。研究结果表明,海底沉积层中的纵波具有明显的频散现象,这种频散现象与理论预期结果相吻合,而且由Biot理论得到的纵波频散规律和现场测试结果有较好的一致性,但对于纵波的衰减,二者符合得不好,这是因为Biot理论模型的假设条件和海底沉积层的差别较大造成的。计算声场显示,当声源放置在海水中时,在沉积层中产生三种转换波;当声源放置在沉积层中时,在沉积层中产生了多种类型的波。在某些条件下,海底沉积层中的横波速度低于慢纵波速度。Velocity and the attenuation of acoustic waves propagating in marine sediment are investigated experimentally and theoretically based on the Blot theory. In order to explain the results of in situ measurements and the phenomena of wave propagation in seafloor environment, the Biot＇s theory and a high-order staggered grid finite-difference method are used. Velocity of P-wave obtained from in situ measurements is in good agreement with the Blot＇s analytical solutions, but attenuation is not. Numerically modeled fields show that different source locations result in different transmitted waves and, in some cases, shear waves propagate at slower velocity than that of slow compression waves, which is important for in situ measurements.

关 键 词：海底沉积物 现场测试 有限差分 孔隙介质Biot理论 

分 类 号：TB566[交通运输工程—水声工程]