Numerical Simulation Of Flow Field And Analysis Of Influencing Factors Of Current Force Of The Water Flow Over A Gear-type Mixture Embankment

The gear-type mixture embankment is a kind of new structure,which was used between Taicang and Nantong in the first-stage deep water channel project from Nanjing to the estuary in the Yangtze River.It is still in the early stages of application and research.So there is no clear understanding of the distribution of pressure on the gear-type component and it's influence on the flow field.And there is no theoretical or empirical formula can be directly applied to computing the current force of water flow over a gear-type mixture embankment.Therefore,in order to promote this new type of structure,we must have a further study on it‘s impact to the flow field and its mechanical characteristics under the action of water flow.A numerical simulation of flow field of the water flow over a gear-type mixture embankment based on CFX software was presented in this paper.The numerical model involved the full Navier-Stokes equations,the two-equation k-? turbulent model and Reynolds equation.In order to track the free surface,the volume of fluid(VOF)method was employed.Analysing the free surface and flow field of the water flow over a gear-type mixture embankment,extracting the current force on the gear-type components and comparig it with the results of theoretical formula are the main tasks of this paper.The results show that the numerical simulation method used in this paper can be applied to 3D numerical simulation of the flow around an obstacle or over an embankment and to calculate current force of a complicated geometry.What's more,we find that the flow field of the water flow over a gear-type mixture embankment is fully different to the circle flow field,and the theoretical formula can't be directly applied to calculating the current force of the water flow over a gear-type mixture embankment.To further understand the mechanic features of the action of water flow on the gear-type mixture embankment,the single variable control method is adopted.Then numerical simulations are performed respectively according to different incident velocities,different incident angles and different relative heights of the embankment.And analysing the impact of these factors on current force of the water flow over a gear-type mixture embankment is the core content.The results show that the current force of water flow over a gear-type mixture embankment increases with the incident velocity and angle of current as well as the relative height of embankment.But the changing trends all have their own characteristics.