The effect of tidal force and topography on horizontal convection

Ding, Guang-Yu1,2,3; He, Yu-Hao1,2,3; Xia, Ke-Qing1,2,3,4

2021-12-09

10.1017/jfm.2021.1026

JOURNAL OF FLUID MECHANICS   影响因子和分区

0022-1120

1469-7645

We present a numerical study on how tidal force and topography influence flow dynamics, transport and mixing in horizontal convection. Our results show that local energy dissipation near topography will be enhanced when the tide is sufficiently strong. Such enhancement is related to the height of the topography and increases as the tidal frequency omega decreases. The global dissipation is found to be less sensitive to the changes in omega when the latter becomes small and asymptotically approaches a constant value. We interpret the behaviour of the dissipation as a result of the competition among the dominant forces in the system. According to which mechanism prevails, the flow state of the system can be divided into three regimes, which are the buoyancy-, tide- and drag-control regimes. We show that the mixing efficiency eta for different tidal energy and topography height can be well described by a universal function eta approximate to eta(HC)/(1 + R), where eta(HC )is the mixing efficiency in the absence of tide and R. is the ratio between tidal and available potential energy inputs. With this, one can also determine the dominant mechanism at a certain ocean region. We further derive a power law relationship connecting the mixing coefficient and the tidal Reynolds number.

buoyancy-driven instability topographic effects mixing and dispersion

SCI ; EI

英语

第一 ; 通讯

National Natural Science Foundation of China[12072144] ; Research Grants Council of HKSAR["CUHK14301115","CUHK14302317"] ; Department of Science and Technology of Guangdong Province[2019B21203001]

Mechanics ; Physics

Mechanics ; Physics, Fluids & Plasmas

WOS:000728249100001

CAMBRIDGE UNIV PRESS

20215211389015

Buoyancy ; Energy dissipation ; Mixing ; Potential energy ; Reynolds number ; Tidal power

Energy Losses (industrial and residential):525.4 ; Tidal Power Plants:611.2 ; Fluid Flow, General:631.1 ; Chemical Operations:802.3 ; Physical Properties of Gases, Liquids and Solids:931.2 ; Materials Science:951

ENGINEERING

2-s2.0-85121613078

Web of Science

1.Southern Univ Sci & Technol, Ctr Complex Flows & Soft Matter Res, Shenzhen 518055, Peoples R China
2.Southern Univ Sci & Technol, Dept Mech & Aerosp Engn, Shenzhen 518055, Peoples R China
3.Chinese Univ Hong Kong, Dept Phys, Hong Kong, Peoples R China
4.Southern Univ Sci & Technol, Guangdong Prov Key Lab Turbulence Res & Applicat, Shenzhen 518055, Peoples R China

Ding, Guang-Yu,He, Yu-Hao,Xia, Ke-Qing. The effect of tidal force and topography on horizontal convection[J]. JOURNAL OF FLUID MECHANICS,2021,932.

Ding, Guang-Yu,He, Yu-Hao,&Xia, Ke-Qing.(2021).The effect of tidal force and topography on horizontal convection.JOURNAL OF FLUID MECHANICS,932.

Ding, Guang-Yu,et al."The effect of tidal force and topography on horizontal convection".JOURNAL OF FLUID MECHANICS 932(2021).