Numerical Research On The Characteristics Of Flow Around A Cylindrical Structure With A Rotating Plate

Cylindrical structures are widely used in the field of nature and practical engineering.Many important parts of the project are cylindrical structures.When fluid flows around these cylindrical structures,it creates complex flows around these structures.In particular,periodic fluid force is caused by the alternate shedding vortex produced periodically in the wake.The fluid force will produce great fluctuating drag and lift force on the cylindrical structure,which cause fatigue failure of the cylindrical structure and destroy the cylindrical structure.Therefore,it is necessary to analysis the suppression of vortex shedding in flow around a cylinder.Many scholars have researched the suppression method of vortex shedding in flow around a cylinder.In this paper,combined with numerical forecasting techniques,a rotating plate set on the end of the cylinder and to explore the effect of vortex shedding in flow around a cylinder made by the rotating plate.Based on the CEL language,the principle of rotor and stator and the mesh motion technique are combined in the numerical forecast.The Large Eddy Simulation model–Smagorinsky turbulence model is used to research the numerical simulation of flow around a cylinder with a rotating plate in high Reynolds number.In this paper,on the basis of the advantages and disadvantages of various turbulence models,the Large Eddy Simulation-Smagorinsky turbulence model combined with SIMPLE algebra solution is used to simulate the phenomenon of boundary layer separation on the cylinder and turbulent motion in the rotating domain.By changing the rotation parameters and the flow condition,the effect of vortex shedding in flow around a cylinder made by the rotating plate and the change rule of the force characteristic of the cylinder with different rotation parameter are simulated and analyzed.The rotation parameters that can suppress vortex shedding in the wake behind the cylinder effectively are contrasted and analyzed.The results of numerical simulation are shown that:In the sub-critical region,the rotating plate whose rotation angle is 15°and rotation frequency is 1.5f_s(f_s is the vortex shedding frequency in the wake behind the bare cylinder)has the best inbibition effect of vortex shedding.Compared with the bare cylinder,the rotating plate with this rotation parameters reduces the average drag coefficient by more than 20%,the fluctuating drag coefficient and the fluctuating lift coefficient by more than 60%.In the super-critical region,the rotating plate whose rotation angle is 10°and rotation frequency is 1.5f_s has the best inbibition effect of vortex shedding.Compared with the bare cylinder,the rotating plate with this rotation parameters reduces the average drag coefficient by more than 30%,the fluctuating drag coefficient and the fluctuating lift coefficient by more than 60%.