海底管线溢油数学模型研究

基于Lagrangian积分技术,推广了海底管线溢油数学模型,在模型中首次考虑了溢油的乳化,同时还考虑了剪切卷吸和对流卷吸以及溢油的扩散和溶解.该模型不但能够模拟不分层或分层环境中的水下溢油轨迹,而且还可以在改变水流流速的环境下模拟.讨论了不同Froude数、分层数以及溢油速度和水流速度比下的溢油轨迹和浓度值,通过多次数值模拟发现在改变小孔直径大小而保持Froude数以及溢油初速度和水流流速比不变的情况下,溢油的轨迹变化很小,且溶解总量和乳化总量都很小.将数值模拟结果与实验值进行对比,获得了令人满意的数值结果,说明该模型具有较高的准确性和可靠性,能够反映出海底管线溢油的扩散及上升轨迹.

Study of mathematical model for oil spills from seabed pipeline

A comprehensive mathematical model is developed to simulate the behavior of buoyant oil jets that result from the seabed pipeline. The mathematical model is developed based on a Lagrangian integral technique. The model considers the emulsification for the first time, the shear induced entrainment, the forced entrainment, the diffusion and dissolution of oil spills from the pipeline to the ambient. The model can simulate the behavior of oil in stratified or unstratified hydraulic environments. The presence of a variable ambient current is considered. The trajectory and concentration of oil spills are discussed in variable Froude number, stratified number and the ratio between the magnitudes of jet velocity and ambient velocity. The total dissolution and emulsification are both a little. The numerical model is tested against a variety of conditions. The cases compared include 2-D and 3-D jet trajectories. All comparisons show that the numerical model results match very well with the experimental data. So the model is exact and reliable and can give the diffusion and buoyant trajectories of oil spills from seabed pipeline.