海底沉积物声速与物理性质的理论关系  

Theoretical relations between sound velocity and physical-mechanical properties for seafloor sediments

作　　者：龙建军[1] 李赶先[2] 

机构地区：[1]广东工业大学机电工程学院,广州510006 [2]中国科学院南海海洋研究所边缘海地质重点实验室,广州510301

出　　处：《声学学报》2015年第3期462-468,共7页Acta Acustica

基　　金：国家自然科学基金(41176034;11174299;41476028);声场声信息国家重点实验室开放课题(SKLA201408)资助

摘　　要：为建立海底沉积物声速与物理性质的关系,引入密度变化比和弹性模量变化比为参数描述海底沉积物声速。密度变化比是描述声速的一个复合参数,由孔隙率、固相密度和海水密度三个物理参数表示;弹性模量变化比是描述声速的另一个复合参数,由孔隙率、固相体积模量和海水体积模量三个物理参数表示;声速公式可展开为这两个复合参数的泰勒多项式。两个复合参数的变化构成声速曲面,声速曲面包含了声速特性与沉积物性质的完整信息;而单参数声速公式是声速曲面上的一条曲线。数值计算与测试结果对比表明:把孔隙率-声速经验公式变换为参考声速乘以一个调制函数的标准形式,各个海区的孔隙率-声速经验公式的调制函数是相当接近的。论文导出的声速公式与Wood声速公式的区别在于弹性模量的模型不同。To describe the wave velocity of seafloor sediments, two composite parameters that are the ratio of density variation to density （RDVD） and the ratio of the elastic modulus variation to elastic modulus （REMDEM） are introduced in this paper. The RDVD is one composite parameter which is consisted of porosity, density of solid-phase and water density, and the REMDEM is another composite parameter which is expressed by porosity, bulk modulus of solid-phase and the bulk modulus of seawater. Sound speed formula can be expanded to Taylor power polynomials of the two composite parameters above. The two composite parameters vary to constitute a sound speed surface, and the surface contains the whole information of acoustic characteristics and sediment physical properties. A porosity-sound speed function is a curve on the sound velocity surface. Numerical calculation and comparison of test results show that： if the empirical formula of porosity-sound velocity of is converted to a reference sound velocity multiplied by a standard form of modulation function, the modulation functions empirical formula of porosity-sound velocity from various sea zones are quite close each other. The difference between the formula of sound speed in the papers and Wood one is in elastic modulus model.

关 键 词：海底沉积物 物理性质 声速 理论关系 经验公式 复合参数 弹性模量 密度变化 

分 类 号：O427.1[理学—声学]