摘要
Complex interactions of plates with ambient fluid are common in daily lives,e.g.flags flapping in wind,aerofoils oscillating in flow.Recently,the feasibility to harvest energy using the flutter motion has been demonstrated.The objectives of this study are to systematically explore the effects of the material damping on flag flutter,and then to study the energy interchange between the fluid and the flag.In this study,a two-dimensional model was developed.Three dimensionless parameters govern the system,i.e.the mass ratio between the structure and the fluid,the dimensionless fluid velocity and the dimensionless material damping.Results show that the critical velocity increases with the increase of the material damping.The oscillation frequency of the flag decreases with the increase of the material damping,and the time-averaged energy dissipation rate initially increases and then decreases.The increase of the material damping causes the transition of the system from a higher frequency oscillating state to a lower frequency oscillating state,and from a chaotic state to a periodic state.
基金
supported by the National Natural Science Foundation of China(Grant Nos.10832010,11002138 and 11102027)
the Innovation Project of CAS(Grant No.KJCX2-YW-L05)
