Numerical Research Of Suppression Mechanismfor Turbulent Flow Around Circular Cylinderusing A Splitter Plate

Cylindrical structures are widely used in the field of nature and ocean engineering,including columns of TLP platforms,columns of floating wind turbines,marine risers and so on.When high-speedfluid flows around a cylindrical structure in a certain state,periodic vortices often shed alternately behind the circular cylinder.Once the vortex shedding frequency is close to the natural frequency of the structure,the phenomenon of resonance occurs in the structure,and the structure will be subjected to great drag and lift force,resulting in horizontal and vertical oscillation,which is called vortex-induced vibration(VIV)or vortexinduced motions(VIM).It may give a great destruction to the structure,even cause serious disasters.Thus research on suppression method for VIV and VIM has become a subject in great demand of present academic research field.The cut-in point of this research is viscous flow around a circular cylinder,designing splitter plate at the back region of cylindrical structure to investigate the suppression of vortex shedding caused by boundary layer separation.aiming at reducing or inhibiting VIV or VIM of the cylindrical structure in the point of fluid movement.At high Reynolds numbers,the issue of flow around a circular cylinder is closely related to the physical phenomenon including turbulent variability,boundary layer separation,incomplete transition and shear layer separation point drift.This paper based on the OpenFOAM open source code,improved and embedded the advanced turbulence model,carried out the numerical calculation and prediction technology research on inhibitory mechanism of suppression board to cylindrical wake back flowing.Thr defects of the standard k-? modelwas focused on,andmodified k-?modelwasproposed baesd on energy model aiming atincreasing the intensity of vortex distribution in wake field to improve the calculation precision of fluctuatingforce.Based on the OpenFOAM(the open source code)and modified model,the method of discrete numerical superiority and PISO algorithm are researched,and the results are verified using iconic model to ensure the correctness and accuracy of numerical algorithm in this paper.On this basis,a series of numerical simulation on 2D viscous flow around a circular cylinder at different Reynolds numbers is carried out to study the mechanism of the suppression effect of the lengthof the splitter plate to different hydrodynamic coefficients and flow condition.Based on 2D cases,3D numerical simulation is carried out to study the mechanism of the suppression effect of the spanwise length and the position of the splitter plate to different hydrodynamic coefficients and flow condition,which provides a scientific theory and reference for the engineering design.