Breaking dam with Fluent2D and KratosStructure2D

This example simulates a dam-break on a top-fixed flexible gate. The liquid, initially located in a free-surface tank, imposes a variable pressure on the bending flexible gate. This case has been examined numerically and experimentally by Antoci et al. [1]. Here, this 2D FSI calculation is performed with Fluent and Kratos Multiphysics.

For details about geometry, parameters and boundary conditions refer to the example with Fluent and Abaqus.

Coupling algorithm

The coupling technique used is IQN-ILSM with reuse of $q = 50$ time steps. These are used to stabilize and accelerate the convergence.

Predictor

The initial guess at each time step is made using the linear predictor.

Convergence criterion

Two convergence criteria have been specified:

• The number of iterations in every time step is larger than 20.
• The residual norm of the displacement is a factor $10^{3}$ lower than the initial value.

The simulation stops as soon as one of the two criteria is met.

Solvers

Fluent is used as flow solver. The provided mesh is triangular. When the gate bends, remeshing is performed to preserve its quality. A script to regenerate it using Gambit is included. This script allows the resolution and geometric parameters to be changed.

The structural solver is Kratos Multiphysics. First-order, quadrilateral, plane strain elements are used.

To exchange information between the solvers on the fluid-structure interface, the use of mappers is required. In the structural solver wrapper, a linear interpolation mapper is used to interpolate in the x- and y-direction from and to the coupled solver.

References

[1] Antoci C., Gallatie M. and Sibilla S., "Numerical simulation of fluid-structure interaction by SPH", Computers & Structures, vol. 85, no. 11, pp. 879-890, 2007.