Fluid-structure interaction analysis of thin delta wing at transonic speed

Abstract

The oscillation of a thin flat-delta wing at transonic speed was investigated by fluid-structure interaction (FSI) analysis based on open-source software. The analysis model was composed of fluid solver SU2, structure solver CalculiX, and coupler preCICE. It was found that self-induced oscillation of the delta wing is induced by the compression and expansion waves and elastic deformation in the transonic regime. The primary frequency of the oscillation was approximately 25 Hz for all speeds considered herein. However, the eigenfrequencies of the present condition of the delta wing, which are 9.62, 36.69, 51.22, 88.94, etc., did not correspond to the oscillation frequency. The phase delay of pressure for the deformation of the delta wing appeared in the oscillation. After the maximum displacement of the wing tip, the pressure almost follows the displacement until the minimum displacement, and no instability occurs. However, there is a phase delay in the pressure from a certain displacement after the maximum displacement. It was suggested that this phase delay causes instability in displacement.