A simple mass-conserved Level Set Method for FSI problems with free-surface flows

Resumo

The present work is dedicated to the numerical simulation of Fluid-Structure Interaction (FSI) problems involving floating bodies subjected to the action of free-surface flows. The free-surface treatment is considered using the Level Set Method (LSM), which historically has a drawback of being too dissipative, leading to mass conservation errors. In a relatively new modification, proposed by Yuan et al. (2018) and implemented here, a source or sink term is introduced into the original Level Set equation to compensate the mass loss or offset the mass increase, leading to better results. Also, in our model, the flow equations are discretized using the Characteristic-Based Split (CBS) method in the context of the Finite Element Method (FEM). The structure is kinematically described using a rigid body approach. The system of equations of motion is discretized in time using the implicit Newmark and a-Generalized methods. Several problems are simulated, comparing the results with those from the original LSM, demonstrating that the modified version has the capability of accurately capturing the interface and keeping the mass conservation.