基于时间平均的海底沉积物声速预测

在海底沉积物声速预测中,把不同海域的物理性质完全不同的沉积物试验数据拟合出一个统一的方程存在不足,不但数据过于离散,而且方程中参量的物理意义不明确。借鉴Wyllie等建立的时间平均方程的思路,基于声传播过程中路程、时间和声速之间的基本关系,引入了表征固液双相之间的堆垒方式和耦合状态对声传播路径影响的耦合系数,建立了沉积物声速预测模型。将鹿回头外海、南海南部和北部的沉积物测量数据进行线性回归分析,分别得出适用于不同海域的沉积物声速预测模型,拟合的复相关系数较大,偏差较小,证明该模型能够反映声速随孔隙度的变化规律,且各参数物理意义明确,具有一定的研究和理论探索意义。

A study on forecasting sound velocity of sea-floor sediments based on the time-average method

When predicting the sound velocity of sea-floor sediments, is not appropriate to sum up a uniform empirical equation from the sea-floor sediment data of different sea areas, where the sea-floor sediment’s physical properties are even completely different. Not only the data are discrete too, but the parameters in the equation are lack of exact physical meaning. Based on the idea of Wyllie’s time-average equation, a sea-floor sediment sound velocity forecasting model is established with the relationship of distance, time and velocity. In the model, the introduced parameter coupling coefficient stands for the impact of stacking and coupling mode of a solid-liquid two-phase system on a sound propagation.The measurement data of sea-floor sediment samples from offshore Luhuitou, the southern and northern South China sea are applied to verifying the model, and three different sound velocity forecasting equations are fitted out. The conclusion is the model can exactly reflect the relation between sound velocity and porosity, moreover, the parameters in the model have physical meaning.