Aerodynamic analysis of flapping-pitching flat plates

Modern wind energy industry is highly under the influence of the advances in aerospace and has borrowed and adopted many new and innovative concepts from that industry. With the aim of exploring potential benefits of flapping blades in wind turbines, this paper presents the preliminary results of the numerical simulation of a flapping-pitching rectangular flat plate in a uniform air flow. Various combinations of flapping amplitude, flapping frequency and pitching amplitude are analysed and their effect on the instantaneous and maximum lift coefficient is presented. The change in the flapping frequency and amplitude were shown to have considerable effect on the lift coefficient. It can be deduced from the results that the lift coefficient is influenced by the flapping frequency and flapping amplitude combination. For the size and geometry presented in this study, the lift coefficient is most affected by the flapping amplitude when compared to the flapping frequency. The results indicate that the pitching amplitude initially enhances the lift coefficient. However, excessive pitching amplitude results in low lift coefficient.