Hydrostatic and nonhydrostatic simulation study on the frontal collision of buoyant plumes
Abstract
Buoyant plumes from different river mouths extensively collide and converge in coastal areas worldwide, but these interactions and dynamics have not been extensively studied. Plume-to-plume interactions have been mainly investigated using hydrostatic simulations so far, which have limitations in terms of flow structure resolution. This study conducts a comprehensive investigation on both hydrostatic and nonhydrostatic simulations to understand the dynamics of the frontal collision of two buoyant plumes. The results show that nonhydrostatic simulations distinctly differ from hydrostatic simulations. Moreover, nonhydrostatic simulations yield plume evolutions that are more in line with the physical reality and field observations in terms of the flow structures. Nonhydrostatic simulations reveal bore-like structures at the rear of the plume front, clearly exhibiting their effects on the shape evolution and interfacial entrainment. Furthermore, the existing classification of plume collision is reexamined, and the basic dynamics and collision types under nonhydrostatic simulations are elucidated. Additionally, dynamic pressure characteristics are investigated, which suggests that dynamic pressure is the key to the generation and evolution of vortex structures.
Funder
National Key Research and Development Program of China
Fundamental Research Funds for the Central Universities
Research funding of China Three Gorges Corporation
Water Conservancy Science and Technology Project in Jiangsu Province
Subject
Condensed Matter Physics,Fluid Flow and Transfer Processes,Mechanics of Materials,Computational Mechanics,Mechanical Engineering
Reference79 articles.
1. Mixing and transport in coastal river plumes;Annu. Rev. Fluid Mech.,2015
2. River plumes as a source of large-amplitude internal waves in the coastal ocean;Nature,2005
3. An observational and numerical study of river plume dynamics in Otsuchi Bay, Japan;J. Oceanogr.,2016
4. Physical processes in the ROFI regime;J. Mar. Syst.,1997
5. L.-F. Lu , “ Numerical modeling of the dispersal and mixing processes within the plume of the Changjiang River Estuary,” Ph.D. thesis ( Shanghai Jiao Tong University, 2008).