Formation and estimation of peak impact force on suspended pipelines due to submarine debris flow
Formation and estimation of peak impact force on suspended pipelines due to submarine debris flow
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DOI：
10.1016/j.oceaneng.2019.106695
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发表时间：
2020
影响因子：
5
通讯作者：
Xuesheng Qian;Jingping Xu;Yong Bai;H. Das
中科院分区：
文献类型：
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作者：
Xuesheng Qian;Jingping Xu;Yong Bai;H. Das
近年来，海底泥石流对悬空管道的影响得到了广泛的研究。确定了冲击力的典型模式： 在低雷诺数时，它会增加直至达到稳定的平台；否则，它会急剧上升到峰值，然后下降到稳定值。然而，峰值冲击力的形成机制仍然是一个悬而未决的问题。为了解决这个问题，使用 ANSYS Fluent 18.0 开发了二维 (2D) 双相（泥浆和水）数值模型。该模型用于模拟恒速海底泥石流对悬空管道的冲击。在此，观察到悬吊管道上的峰值冲击系数和稳定冲击系数（它们是无量纲冲击力）的类似模式。揭示了峰值冲击力的形成机制。研究发现，稳定的冲击力依赖于海底泥石流的恒定速度，而峰值冲击力则取决于初始冲击时的速度和局部加速度。此外，提出了雷诺数与惯性系数和阻力之间的关系来估计峰值和稳定冲击力。将这些关系与文献中可用的实验和数值数据集进行比较，并建议将来进行实验室实验以获得更多测量数据集以进行进一步验证。
In recent years, submarine debris-flow impact on suspended pipeline has been extensively investigated. Typical modes of impact force are identified: At low Reynolds number, it increases till reaches a stable plateau; otherwise, it sharply rises to a peak before decreasing to a stable value. However, the formation mechanism of peak impact force remains an open question. To address this issue, a two-dimensional (2D) biphasic (slurry and water) numerical model is developed using ANSYS Fluent 18.0. This model is used to simulate the constant-speed submarine debris-flow impact on a suspended pipeline. Herein, similar modes of peak and stable impact coefficients, which are nondimensionalized impact forces, on a suspended pipeline are observed. The formation mechanism of peak impact force is revealed. It is found that, the stable impact force relies on the constant speed of a submarine debris flow, while peak impact force depends on its velocity and local acceleration at initial impact. Moreover, the relationships between Reynolds number and coefficients of inertia and drag are proposed to estimate the peak and stable impact forces. The relations are compared to experimental and numerical datasets available in literatures, and laboratory experiments are recommended in future to obtain more measured datasets for further verification.