The analysis of pitching wing with elastic deformation

摘要

In this paper, the thrust generation, the efficiency and the flow field of pitching wing with elastic deformation by fluid force are investigated numerically. The Navier-Stokes equation and the equation of elastic deformation are combined by using the Newton- Raphson method. Then, the calculation of flow field and deformation of elastic wing are carried out simultaneously. The thrust generated by an elastic wing exceeds the thrust of rigid wing with the increase of pitching frequency. Furthermore, the efficiency of pitching wing with appropriate elasticity becomes higher than that of rigid wing. Elastic deformation of wing increases the thrust component of fluid force, and the power needed for pitching motion decreases by deformation of wing. These are the main factors that improve the characteristics of thrust generation and the efficiency of elastic wing. The optimal values of flexural rigidity exist for both thrust generation and efficiency respectively. The pitching wing with the optimal value of flexural rigidity improves the characteristics of thrust generation and efficiency substantially.