Co-Simulation for VIV Analysis Using Immersed Boundaries and Geometrically Exact Beam Theory with Contact

Luiz Felipe Marchetti Couto¹; Henrique Campelo Gomes¹; Alfredo Gay Neto¹; Paulo de Mattos Pimenta¹

¹ Polytechnic School at the University of São Paulo

doi:10.20906/CPS/CILAMCE2015-0901

Resumo

This work deals with a class of fluid-structure interaction problems in which the structure can move with large displacements including contact interaction with other bodies or itself. The structure is modeled using geometrically exact rods, including the possibility of contact interaction with rigid walls representing the boundary of the desired physical domain. Furthermore, self-contact searching is also addressed for particular situations when the structure tries to touch itself. Both contact with the walls and self-contact consider large displacements possibility, including normal and friction effects using a penalty approach. The interaction between fluid and structure domains is solved by an immersed boundary approach that uses discontinuous Lagrange multipliers to enforce kinematic and force equilibrium along the interface between the non-matching overlapping meshes, in an alternative to usual Arbitrary Lagrangian Eulerian (ALE) approaches. The engineering applicability of the proposed work is of great interest to deep-water offshore oil exploitation. Risers structures usually are subjected to sea current effects and many important phenomena such as vortex-induced vibration (VIV) is a result of fluid-structure interaction. The proposed technique uses few elements to solve the structural problem, once structural rod elements are considered. Bi-dimensional unsteady flow of an incompressible viscous fluid is adopted, and the interaction with the structural model is enforced by a separate solution of structure and fluid problems, connected by loading and displacements updating during simulation, step by step, along a dynamic transient time evolution.

Palavras-chave: Exact Beam Theory; Contact; Fluid-Structure Interaction; Immersed Boundaries