Numerical And Experimental Investigation Of The Wake Behind A Rotary Oscillating Plate

The vibration of bridges,high-rise buildings,energy collecting plates caused by wind,the vibration of oil platform vibration damping plates in the ocean currents,and the flutter of wings in aircraft fight can be carried out using plates or thin rectangular columns as simplified models to do numerical and experimental research.By studying the wake changes of rotating and oscillating plate,it can lay a foundation for control of wind vibration and has important engineering significance.In this paper,wind tunnel experiment and numerical simulation are combined to find typical working conditions of vortex modes of 2S,2P,P+S,to verify the consistency of experimental and simulation results.Fixed Reynolds number Re=2900,plate rotation amplitude variation rangeθ=2.5°～50°,dimensionless vibration frequency f_eH/V∞=0.005～0.129,the typical working conditions of four vortex shedding modes are determined within the research scope(Three typical modes and a new mode called 2T).In each mode,the vortex morphology and velocity profile are compared through wind tunnel experiment and numeri cal calculation method.The consistency of simulation and experimental results is verified from two aspects of qualitative analysis and quantitative analysis.Using numerical calculation as the main research method,a total of ten vortex modes were found.It was found that the vortex mode of the wake of the rotating oscillating plate changed continuously with the increase of amplitude and vibration frequency.The change trend is from complex vortex structure to single structure gradually.In addition,chang ing amplitude and vibration frequency will also have different effects on vortex cut off length,lift and drag coefficient,power spectrum,wake width,and pressure distribution.