Experimental and numerical study on gas release and dispersion from underwater soil

• Published in: Process safety and environmental protection Vol. 149; pp. 11 - 21
• Main Authors: Geng, Zhiyuan, Li, Xinhong, Chen, Guoming, Zhu, Hongwei, Jiang, Shengyu
• Format: Journal Article
• Language: English
• Published: Rugby Elsevier B.V 01.05.2021; Elsevier Science Ltd
• Subjects: Buried pipes; Gas pipelines; Gas plume; Mathematical models; Numerical models; Numerical simulation; Plumes; Pressure effects; Risk assessment; Small-scale experiment; Soil dispersion; Soils; Subseagas release; Underwater; Underwater pipelines; Water depth; Numerical simulation; Subseagas release; Gas plume; Small-scale experiment
• ISSN: 0957-5820; 1744-3598
• DOI: 10.1016/j.psep.2020.09.065

This paper focuses on the dispersion behavior of gas released from underwater soil by using experimental and numerical approaches. A small-scale experimental system is developed and a number of release scenarios are carried out. The results indicate that the released gas breaks through the sand layer after consuming a certain amount of initial energy and enters the water in the form of bubble plumes, which is similar to the theoretical model. The plume interacts intensely with the surface and forms a fountain with a periodic change in height. The effect of leak pressure, water depth and buried depth on plume behavior and critical parameters including plume diameter, fountain height and rise time are discussed. The experimental data are also utilized to verify the effectiveness of the presented numerical model using Eulerian-Eulerian volume of fluid (VOF) approach. The validated numerical model is subsequently employed to analyze three full-scale scenarios, and the results show good consistency with the experiments. Both the experiments and numerical models are of great value for evaluating the consequences of gas released from underwater buried pipelines and providing data and theoretical support for the subsequent risk assessment.