波流耦合下围油栏栏前油水界面稳定性及拦油失效机理研究

In recent years, such as the Gulf of Mexico oil spill and the Dalian “7.16” oil spill accident have the potential to cause significant damage to the marine ecological environment. Oil booms are one of the most widely used equipment used to respond to an oil spill in marine or inland waters. The crucial impact factors on the oil containment efficiency and predicting the containment failure are oil-water interface stability and effective boom draft, the latter defined as the draft available at a given moment considering the displacements of the free surface in the vicinity of the boom and those of the boom itself, which is affected by the environmental parameters and the oil parameters. However, there is insufficient information on oil containment failure mechanism under wave-current coupling conditions. Here, the impact factors on oil-water interface stability before oil boom and containment failure mechanism will be studied through theoretical analysis, numerical simulations and physical experiments, including: first, the movement responses of oil boom under the wave and current conditions are calculated by theoretical analysis on fluid- structure coupling and numerical simulation technology of Dynamic Grid Algorithm, and validated with the results of physical experiments. Then, the computational hydrodynamic model and its boundary and initial conditions of oil-air-water three phase flow in the numerical wave tank are studied by numerical simulation. Finally, the specific gravity of oil, current velocity, wave steepness and effective oil boom draft are used to evaluate how the pressure gradient along the boom varies and affects the oil-water interface stability and oil containment failure velocity under coplanar and opposing current conditions, pure wave and pure current conditions. The results of this project can provide useful data for oil boom type choosing for Oil Spill Response.

近年来诸如墨西哥湾和大连“7.16”海洋溢油事故频发，对海洋环境造成严重危害，围油栏是处理海上溢油事故中一种常用的、有效的设备。围油栏的有效栏深受环境参数及油品参数的影响，与栏前油水界面稳定性是影响拦油效率以及围油栏失效的主要因素，关于波流耦合下围油栏拦油失效机理的研究仍不充分。鉴于此，本项目拟通过理论分析、数值模拟和物理实验相结合研究波流作用下栏前油水界面稳定性影响因素并探索分析其拦油失效机理，具体内容包括：首先通过流固耦合理论分析计算波流作用下浮子式围油栏运动响应，并用物理实验进行验证；然后通过数值模拟研究波流水槽内油-气-水三相流的计算流体动力学建模及其边界条件和初始条件，最后以油水密度比、水流流速、波陡、围油栏有效栏深为参数，研究波流同向、逆向及纯波浪、纯水流等不同工况下围油栏栏前压力梯度变化及其对油水界面稳定性和拦油失效速度的影响规律，为溢油应急反应中围油栏选配提供依据。

近年来诸如墨西哥湾和大连“7.16”海洋溢油事故频发，对海洋环境造成严重危害，围油栏是处理海上溢油事故中一种常用的、有效的设备。围油栏的有效栏深受环境参数及油品参数的影响，与栏前油水界面稳定性是影响拦油效率以及围油栏失效的主要因素，关于波流耦合下围油栏拦油失效机理的研究仍不充分。鉴于此，本项目通过理论分析、数值模拟和物理实验相结合研究波流作用下栏前油水界面稳定性影响因素并探索分析其拦油失效机理，具体内容包括：探索波流耦合作用下栏前压力梯度变化规律，即对波浪水流作用下栏前复杂耦合流场水力特性进行研究。通过理论分析和实验相结合，分析波流耦合作用下栏前油层存在形态与运移演变规律、栏前油层聚集及存在形态与分布规律和波流耦合作用下栏前流场中围油栏-水-油-空气多相介质相间作用力，建立相应的栏前压力梯度与油层厚度或长度、水流速度、波陡等参数的关系，建立波流耦合作用下栏前压力梯度计算模型。探索波流耦合作用下可动浮子式围油栏六个自由度运动响应机理，并同时进行拦油数值实验平台计算流体动力学建模与求解。基于FLUENT 软件及FLOW3D软件，搭建三维围油栏拦油数值模拟实验平台，合理选择多相流数学模型及造波、造流、消波消流模型，构建合理的波流耦合作用下浮子式围油栏六个自由度运动响应模型。研究波流耦合作用下可动浮子式围油栏栏前压力梯度变化及其对油水界面稳定性和拦油失效速度的影响规律。定量详细分析油水密度比值、水流流速、波陡、围油栏有效栏深、围油栏浮重比以及油的运动粘度等参数在波流同向、波流逆向、纯波浪以及纯水流等不同工况下对围油栏栏前压力梯度变化、油水界面稳定性和拦油失效速度的影响规律，为溢油应急反应中围油栏选配及围油栏结构优化提供依据。