PSI - Issue 24

Pierluigi Fanelli et al. / Procedia Structural Integrity 24 (2019) 939–948 Author name / Structural Integrity Procedia 00 (2019) 000–000

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position. This approach, making use also of dynamic reduction strategies (Salvini and Vivio (2006), Salvini and Vivio (2007)), allows to face complex structures with high frequency behavior. This paper describes a specific 2D application of this solver on a simple FSI system. The here-described case recreates the flapping phenomenon of an elastic inverted flag interacting with a wind flow. The structure, fixed at one of the chamber walls, is loaded by a coaxial flow.

2. modsFsiFoam workflow

The modsFsiFoam solver refers to the structure of the icoFsiFoam OpenFOAM solver, which belongs to the Solid Mechanics field, tested in previous works with bad results. It has been chosen to refer to the structure of this solver because of its simplicity and linearity, before the application of further modifications. This FSI solver is applied as transient solver for incompressible, laminar flow of Newtonian fluids with mesh motion. The applied modifications are based on the resolution of the structural domain through the theoretical-based approach, the modal superposition, and, consequently, on the chosen techniques for the pressure field transmission to the struc ture and for the communication of the structure displacement, in terms of fluid mesh movement, which is the input of the FVM fluid dynamic solution. The solver workflow is shown in the figure (1).

t

FVM CFD solution

Fluid patch pressure extrapolation

Modal analysis: modal frequencies and vibration modes

Dynamic analysis: solid CV nodes displacement vector

Fluid patch movement

t+1

FVM CFD solution

Fig. 1. modsFsiFoam solver workflow