Submarine pipelines, as an important tool for oil and gas transportation, have been distributed in offshore oil and gas fields worldwide. Under extreme waves, a large number of submarine pipelines have been damaged in the past decades. In order to investigate the effect of extreme marine environments on the pipelines, the joint effect of solitary waves and background currents on the pipelines is numerically studied in this paper by using a numerical wave tank developed with a free surface tracking approach and the immersed boundary method. The sediment transport module including packed and suspended sediment is incorporated with the flow module. In order to ensure the calculation accuracy of this model, three verification cases related to the wave propagation profile, the hydrodynamic force on the cylinder and the scour hole profile are simulated and the numerical results match the experimental and analytical results well. Given the combined wave exerts on the different pipelines, the environmental variables consider the background current velocity and wave height, and the pipeline arrangement includes the different diameters and the suspended pipeline and tandem pipeline. It is noted that the hydrodynamic characteristics, the forces and the local scour around the pipeline are closely related to the background current and the diameter and layout of the pipeline. It is anticipated that the findings in this paper will enhance our understanding of the damage mechanism of submarine pipeline by waves and may also be useful in future design practices for pipelines.

海底管道，作为石油和天然气运输的重要工具，已经分布在全世界的海上油气田中。在极端的海浪中，在过去的几十年中，大量的海底管道遭到了破坏。为了研究极端海洋环境对管道的影响，本文采用自由表面跟踪方法和沉浸边界方法开发了数值波箱，对孤波和背景电流对管道的联合效应进行了数值研究。 。包括填料和悬浮泥沙的泥沙输送模块与流量模块结合在一起。为了确保该模型的计算准确性，以下三个验证案例与波传播剖面有关，模拟了气缸上的水动力和冲刷孔的轮廓，数值结果与实验和分析结果吻合良好。考虑到组合波作用在不同的管线上，环境变量考虑了背景电流速度和波高，并且管线布置包括不同的直径以及悬挂管线和串联管线。值得注意的是，流体动力特性，管道周围的力和局部冲刷与背景电流以及管道的直径和布局密切相关。可以预期，本文的研究结果将加深我们对波浪对海底管道破坏机理的理解，并且可能在将来的管道设计实践中很有用。