Spatiotemporal modes extraction for partitioned-coupling data between high-enthalpy flow and flexible structure by dynamic mode decomposition

Abstract

A fluid-structure interaction (FSI) analysis model based on the partitioned coupling approach and a dynamic mode decomposition (DMD) approach with a mode sensing approach by the Greedy algorithm were developed for flexible aeroshell, which is one of the innovative atmospheric-entry technologies. This FSI model is composed of open-source software SU2 for the flow field, CalculiX for the structure field, and coupling library preCICE. The present DMD approach reproduced dominant modes from the spatiotemporal data of displacement by the FSI simulation. It was revealed that the deformation of the aeroshell and torus mainly consists of modes combining a swinging motion and membrane deformation of about 160—170 Hz, and translation motion with membrane deformation of 550 Hz. These DMD-reconstructed modes indicated deformations and frequencies are completely different from the natural oscillation modes. This is because the deformations of aeroshell were significantly affected by aerodynamic forces.