【摘要】 基于κ-ε湍流模型,建立了海底管道立管与海洋平台桩腿相连接、海流流经海洋平台桩腿发生绕流现象的三维流场模型,模拟了冲刷过程中不同条件下立管附近流场及压力的变化,研究了海底管道立管局部冲刷机理。模拟结果表明:随着与立管连接的横管悬空量增大,立轴漩涡越来越密集,海底管道局部冲刷速度加快;在一定范围内,随着桩腿与立管间距的增大,冲刷速度加快,但是当该间距增大到一定程度时,冲刷速度逐渐减慢;增大桩腿的直径,可以减少海流携带泥沙量,冲刷作用得以减缓。更多还原

【Abstract】 On the bases of κ-ε turbulent flow model, it is possible to construct 3D flow-field model to reflect circumferential flows of sea currents around spud legs of offshore platform with riser of subsea pipeline connected with spud legs of offshore platform. By using the model, it is possible to simulate the changes of flow fields and pressures around riser under different conditions during erosion. In addition, the mechanism related to local erosion of riser in subsea pipeline is studied. Research results show that the vertical axial vortex is more and more intensive with the increase of the suspended length of horizontal pipe connected with riser. In addition, local erosion of subsea pipeline is accelerated under such circumstances. Within certain scope, erosion velocity is increased with the increase of the space between spud legs and riser. But as soon as the space is increased to a certain limit, erosion velocity is decelerated. By enlarging the diameters of spud legs, it is possible to reduce the washing volume carried by sea currents, and eventually alleviate erosion.更多还原