In this study,two dimensional unsteady flows of cylinder and cylinder with additional fairing close to a free surface were numerically investigated.The governing momentum equations were solved by using the Semi Implic...In this study,two dimensional unsteady flows of cylinder and cylinder with additional fairing close to a free surface were numerically investigated.The governing momentum equations were solved by using the Semi Implicit Method for Pressure Linked Equations(SIMPLE).The Volume of Fluid(VOF)method applied to simulate a free surface.Non-uniform grid structures were used in the simulation with denser grids near the cylinder.Under the conditions of Reynolds number 150624,271123,210874 and 331373,the cylinders were simulated with different depths of invasion.It was shown that the flow characteristics were influenced by submergence depth and Reynolds numbers.When the cylinder close to the free surface,the drag coefficient,lift coefficient and Strouhal numbers will increase due to the effect of free liquid surface on vortex shedding.With additional fairing,can effectively reduce the influence of the free surface on the drag coefficient.Fairing will reduce lift coefficient at high Reynolds numbers,but increase lift coefficient when Reynolds numbers are small.Fairing can effectively reduce Strouhal numbers,thus can well suppress the vortex induced vibration.展开更多
文摘In this study,two dimensional unsteady flows of cylinder and cylinder with additional fairing close to a free surface were numerically investigated.The governing momentum equations were solved by using the Semi Implicit Method for Pressure Linked Equations(SIMPLE).The Volume of Fluid(VOF)method applied to simulate a free surface.Non-uniform grid structures were used in the simulation with denser grids near the cylinder.Under the conditions of Reynolds number 150624,271123,210874 and 331373,the cylinders were simulated with different depths of invasion.It was shown that the flow characteristics were influenced by submergence depth and Reynolds numbers.When the cylinder close to the free surface,the drag coefficient,lift coefficient and Strouhal numbers will increase due to the effect of free liquid surface on vortex shedding.With additional fairing,can effectively reduce the influence of the free surface on the drag coefficient.Fairing will reduce lift coefficient at high Reynolds numbers,but increase lift coefficient when Reynolds numbers are small.Fairing can effectively reduce Strouhal numbers,thus can well suppress the vortex induced vibration.
