Flow And Dynamic Of The Three-dimensional Stratified Fluid Around A Seamount

Due to the vertical difference in temperature and salinity,the ocean is a natural stratified fluid in nature.As the land,the bottom of the ocean also has varying topography.The seamount is one of the representative of marine geology,and its existence in the ocean has an important influence on the flow structure of seawater.The study of the three-dimensional stratified flow around the seamount is of great importance in understanding,developing and using the ocean.In the thesis,numerical simulation method is used to study the influence of the seamount on the upstream and downstream structure of the flow.Qualitative and quantitative conclusions have been obtained by the calculation based on a large number of cases.By comparing flows for different Reynolds numbers(Re)and stratified strengths(K),it is found that the vertical motion of seawater depends on the Reynolds number and the stratification intensity and that the vertical motion magnitude increases with the Reynolds number but reduces with K.The further examination of numerical results shows that there is significant upwelling on the upstream of the seamount.The lower the stratification intensity,the lower the Reynolds number for which the dividing point appears.The scaling relation of the height of the dividing point under homogeneous seawater has been obtained.In addition,according to the quantitative analysis of the vertical flow rate at different sections,the dependence of the vertical flow rate on the Reynolds number is quantified.The three-dimensional flow around the seamount under homogeneous and stratified seawater is analyzed in the thesis.Although the qualitative and quantitative analysis of the upstream and downstream structure has been carried out,it is still necessary to verify further the conclusions in the thesis with theoretical analysis,field measurement and laboratory experiment.