Fluid-elastic structure interaction, otherwise known as hydroelasticity is an important branch of hydrodynamics. An improved hybrid numerical model is proposed in this paper to study the fluid-elastic structure interaction in time domain. The hybrid numerical model is a strongly coupled numerical model created by combining the Fully Nonlinear Potential flow (FNPT) model and the Navier-Stokes equation. The solution to FNPT model was estimated by using the finite element method and the NS model was solved using the Meshless Local Petrov- Galerkin (MLPG) method. The two models are strongly coupled in space and time. This hybrid model is once again, near strongly coupled with the structural solver. The structure used in this study has been numerically described using the Euler-Bernoulli beam equation based on finite element method. The performance of the model has been improved by incorporating the Arbitrary Eulerian-Lagrangian (ALE) scheme to assist particle movement. A new free surface detection scheme has also been incorporated. Further, three different schemes have been proposed and investigated in this paper for fluid (FNPT)-fluid (NS) -elastic structure (Euler-Bernoulli beam equation) coupling.
Fluid structure interaction or Hydroelasticity has been an extensively studied area in the field of hydrodynamics. The mathematical formulations used for establishing the hydroelastic theories evolved from the strip theory formulations. In general, the models can be classified based on the approach as monolithic formulation and partitioned approach. In monolithic formulation, the mathematical model is represented by a single equation. The partitioned approach makes use of the highly developed individual areas and combines these independent areas to build a stable mathematical model. Further, monolithic formulations can be classified based on the simplifying assumptions used in the formulations as linear and nonlinear models. Considerable amount of research has been done in this area in the field of hydrodynamics.
Another approach to solving the mathematical model is by the use of the partitioned approach. Developments in the area of computational mechanics in the recent years along with research in the area of solution estimation techniques such as Finite Element Methods and Mesh-free methods such as SPH, MPS and MLPG_R have resulted in extensive use of partitioned approach for fluid elastic structure interaction problems.
