Numerical Simulation Research On Coriolis Force's Influence On Gulf Tidal Current Movement

Tide waves move in a rotating system created by the rotation of the earth and are affected by gravity,fluid viscous force and Coriolis force.Recognizing and understanding the influence of Coriolis force in the Gulf tidal wave movement is of great significance to the development and utilization of Gulf resources.In this paper,numerical simulation and theoretical analysis are used to study the residual current movement in semi-enclosed bays,estuaries,sand waves and sand ridges under the action of Coriolis force.Chapter ? introduces the numerical models used in the calculation,including the average depth two-dimensional hydrodynamic model and the three-dimensional POM water flow model,and gives the corresponding difference method and calculation process.Among them,the average water depth two-dimensional hydrodynamic model is used for the numerical simulation of 3.1,3.2 and the chapter IV model,and the three-dimensional POM water flow model is used for the hydrodynamic numerical simulation of 3.3 and the chapter V.Chapter ? mainly studies the influence of Coriolis force on tidal wave movement in a semi-enclosed bay.Firstly,the reason for the formation of the tidal ellipse in the semi-closed bay is explained by the analytical solution: The high-frequency wave caused by the coupling of the solid wall boundary and Coriolis force in the semi-closed rectangular bay is the Poincaréwave.Poincaré waves have horizontal standing wave characteristics and longitudinal forward wave characteristics.The standing wave characteristics produce periodic lateral movement of the water body,which leads to the deflection of the velocity vector and the generation of tidal current ellipses.Analyzed the influence of Poincaré waves on the reflection coefficient under different bay aspect ratios.Then the tidal ellipse is formed in different bay shapes.Research the changes under.Taking convergent and divergent bays with different shrinkage scales as examples,the size,inclination,and maximum velocity of the tidal current ellipse are analyzed as a function of the shape of the bay.Finally,the influence factors of the tidal ellipse along the water depth are analyzed,that is,the friction at the bottom of the bed on the tidal current.The influence of the vertical distribution of the ellipse.Chapter ? mainly analyzes the influence of Coriolis force on the tidal wave movement in the estuary.The strength of the fluctuating tidal path is measured by the ratio of the velocity difference between the north and south sides of the estuary to the average velocity of the crosssection.The divergence of the fluctuating tidal path of the estuary is measured around the changes in the ratio of runoff to tide,the ratio of width to depth and the coefficient of Coriolis force.the study.And through the numerical experiments of "no path" and "no tide",the fluctuations in the contribution of the tide and runoff to the divergence of the fluctuating tidal current path are considered separately.Chapter ?mainly explores the influence of Coriolis force on the vertical residual circulation of sand wave and sand ridge topography,discusses the different ratios of sand wave height to water depth,the ratio of tide level to water depth,and the angle between sand ridge direction and tidal current,impact on vertical circulation.The study found that the height of the sand wave itself has an important influence on the characteristics of the vertical circulation in the water area.The higher the initial height of the sand wave,the more obvious the vertical residual circulation,which is more conducive to the further development and maintenance of the sand wave;in addition,the inclination angle of the sand ridge and the tidal current direction will also affect the development of the sand ridge.The circulation is more obvious,which promotes the growth of sand ridges.