海底热液羽流系统对海洋底部热量与物质输运等科学问题的研究具有重要意义。本文采用数值模拟的方法研究在温度层结环境中二维轴对称热液羽流的发展过程,讨论热液羽流不同喷口条件对羽流发展过程的影响。计算结果表明,热液羽流的喷发过程分为2个阶段:上升过程中温度逐渐降低浮力减小,在背景层结的作用下达到稳定的上升高度;其后羽流顶部转向横向输运。喷口温度、喷口半径对热液羽流的上升高度和横向输运能力的影响正相关。
The seafloor hydrothermal system plays an important role in exchanging both thermal energy and chemical components between the ocean and earth crust. The hydrothermal system in a temperature stratified background is simulated using an axisymmetric model, and the influences of spout temperature, spout radius, spout flow velocity are discussed. The results show that the temperature decreases because the plume continues to entrain fluid, the plume overshoots to the maximum plume rise height in the stratified environment eventually. Over time, a laterally spreading intrusion develops above the plume and the plume's transport range at the bottom still remains unchanged. The spout temperature and spout radius have positive correlations with the rise height and lateral range of the hydrothermal plume.
[1] Lowell R P, Rona P A, Von Herzen R P. Seafloor hydrothermal systems[J]. Journal of Geophysical Research:Solid Earth, 1995, 100(B1):327-352.
[2] Kelley D S, Baross J A, Delaney J R. Volcanoes, fluids, and life at midocean ridge spreading centers[J]. Annual Review of Earth and Planetary Sciences, 2002, 30(1):385-491.
[3] Woods A W. Turbulent plumes in nature[J]. Annual Review of Fluid Mechanics, 2010(42):391-412.
[4] Tao Y, Rosswog S, Brüggen M. A simulation modeling approach to hy-drothermal plumes and its comparison to analytical models[J]. Ocean Modelling, 2013(61):68-80.
[5] Lavelle J W, Di Iorio D, Rona P. A turbulent convection model with an observational context for a deep-sea hydrothermal plume in a time-vari-able cross flow[J]. Journal of Geophysical Research:Oceans, 2013, 118(11):6145-6160.
[6] Jiang H, Breier J A. Physical controls on mixing and transport within rising submarine hydrothermal plumes:A numerical simulation study[J]. Deep Sea Research Part I:Oceanographic Research Papers, 2014(92):41-55.
[7] Morton B R, Taylor G, Turner J S. Turbulent gravitational convection from maintained and instantaneous sources[C]//Proceedings of the Royal Society of London A:Mathematical, Physical and Engineering Sciences. The Royal Society, 1956, 234(1196):1-23.
[8] 叶丰, 包芸. 层结环境中热液羽流物质输运范围的模拟计算[J]. 热带海洋学报, 2016, 39(5):97-102. Ye Feng, Bao Yun. Study of hydrothermal plume transport range in a stratified background[J]. Journal of Tropical Oceanography, 2016, 39(5):97-102.
[9] Woods A W, Caulfield C C P. A laboratory study of explosive volcanic eruptions[J]. Journal of Geophysical Research, 1992, 97(B5):6699-6712.