A Conservative Mesh-free Approach for Fluid-structure Interface Problems

The problem of building a methodology to couple fluid and structure is addressed in this paper. If the goal of the fluid-structure simulation is the stability assessment, an important issue to be addressed is the conservation of the momentum and energy exchanged between the participating domains. In realistic aerospace applications, the fluid and structural meshes are not compatible, either because discretized with major geometrical and topological discrepancies, or because different resolution requirements are set. As a consequence, different strategies may be required to solve the interface problem in each specific case. A new scheme is presented, based on the Moving Least Square (MLS) patches technique used in the field of surface reconstruction from N irregularly distributed given data points. The MLS method represents the correct framework which can be easily adapted to different interface problems. The goal is to develop an accurate but flexible method, capable of interfacing arbitrary structural or aerodynamic discretization schemes. A complete independence from the formulation of the structural and aerodynamic solvers is sought, while the conservation properties are retained as far as possible. A few applications are shown to highlight the quality of the proposed scheme.