A modal approach for coupled fluid structure computations of wing flutter

Abstract

In this paper, a modal approach for the fast calculation of flow mesh deformation around a wing is developed based on the elastic solid method of dynamic mesh. The flow mesh domain is assumed to be a pseudo elastic solid. The displacement of the wing and the pseudo elastic solid is continuous at the fluid structure interface. Considering the condition of displacement continuity, the governing equation for the vibration of the wing with the pseudo elastic solid together is derived. The frequencies and mode shapes of the wing and the pseudo elastic solid are computed. Then the nodal displacements for the wing and the flow mesh are computed using modal superposition. The flutter boundary of the AGARD Wing 445.6 is predicted using the present modal approach by considering the first four modes of the wing. The calculated results compare well with the experimental data. The computing time is reduced by 54.8% compared with the pre-existing elastic solid method.