A CFD (computational fluid dynamic) simulation for oil leakage from damaged submarine pipeline

The objective of the present paper is to study the oil flows from damaged submarine pipelines with different leak sizes. CFD (computational fluid dynamic) simulations with FLUENT software are carried out to investigate the process of oil spill from submarine pipeline to free surface. Effects of oil density, oil leaking rate, leak size and water velocity on the oil spill process are examined. High density, slow leaking, small leak size or fast current brings about long time for oil reaching the maximum horizontal migrate distance when it reaches surface. And this maximum horizontal migrate distance increases with the increase of leak size or water velocity, while increases with the decrease of leaking rate. Then, the dimensionless time required for oil droplets which have the longest horizontal migrate distance when they reach the sea surface and the dimensionless longest horizontal distance the droplets migrate when they reach the sea surface are analyzed and the fitting formulas are obtained. Only the formula for the dimensionless longest horizontal distance versus dimensionless density meets the polynomial, other five formulas meet the natural logarithm distribution. Using the formulas we can obtain when and where to see oil reaching the sea surface, and conduct rapid response. Finally, the maximum horizontal migration distance of oil at certain time is predicted, and a forecasting model is proposed. The using methods of fitting formulas and the forecasting model are shown in the paper by examples. These calculated results provide useful guidance to place the oil containment boom.