Cylinder-lamina system fluid–structure interaction problem solved with an original OpenFOAM code

Abstract

In numerical simulations, the partitioned approach allows treating a multi-physics phenomenon as two different computational fields, which are solved separately with their respective mesh discretisation and algorithms. This is of particular interest to fluid–structure interaction (FSI) problems for their complex resolution. In this respect, through the partitioned approach, ModsFsiFoam (MODalSuperpositionFsiFoam) solver has been developed. It allows the application of two different methods for fluid and solid solutions. In particular, it is based on a theoretical approach, the modal superposition principle, for the structural solution; this method provides a certain result for the linear structural field. The FVM (Finite VolumeMethod), by far the most widely used method for fluid-dynamics and gas-dynamics problems, has been used instead to solve the Navier–Stokes equations for an incompressible laminar flow of Newtonian fluid. The interfacial conditions have been used to pass information between the domains through a coupling algorithm. Implemented in OpenFOAM, a development environment consisting of libraries and applications for Linux distributions, written in the C++ source code, ModsFsiFoam solver has been already applied with satisfactory results to a typical fluid–structure interaction case found in literature, i.e. a system composed by an inverted flag treated as a flexible lamina, clamped to a wind tunnel wall, in which airflow is introduced in the axial direction. In this work, ModsFsiFoam solver outputs are compared with a system, the results of which are known for both fluid-dynamics and structural fields. The configuration consists of a laminar incompressible channel flow around a solid structure with an elastic part.