Dam break against a flexible wall: flexibleDamBreak

Prepared by Amirhossein Taran and Philip Cardiff

Tutorial Aims

  • Demonstrates how to perform a multi-phase fluid-solid interaction simulation

Case Overview

This case extends the traditional OpenFOAM damBreak tutorial to include a flexible dam. This benchmark has been examined several times in literature, including by Walhorn et al. [1], Meduri et al. [2], and Ryzhakov et al. [3]. The initial configuration of this example is shown in Figure 1, where a column of water is at rest located behind a membrane on the left side of a tank. At time \(t = 0\), the membrane is removed, and the column of water collapses. During the collapse, the water impacts a flexible obstacle (the "dam") at the bottom of the tank, causing it to deflect elastically. For benchmarking, the horizontal displacement of the dam is tracked over time. Table 1 provides the material properties and geometry data for reference. The solid component employs a neo-Hookean large strain constitutive law. The total Lagrangian solid model (nonLinearGeometryTotalLagrangianTotalDisplacement) is used as the solid solver, and the volume-of-fluid incompressible multiphase fluid model (interFluid) is used as the fluid solver.

Figure 1: Problem geometry and initial conditions

Table 1: Problem Physical Parameters

Parameter Value
Solid Young's Modules (\(E\)) 1 MPa
Solid Density \((\rho)\) 2500 kg m\(^{-3}\)
Solid Poisson Ratio \((\nu)\) 0
Fluid Viscosity\((\mu)\) 0.001 Pa s
Fluid Density \((\rho)\) 1000 kg m\(^{-3}\)
gravity 9.81 m \(s^{-2}\)
L 0.0146 m
H 0.080 m
W 0.012 m


Upon starting the solution, the water column collapses due to gravity and will hit the flexible dam. The solids4foam predictions for the deflection of the top-right corner of the dam are compared with numerical solutions from the literature in Figure 2, showing reasonable agreement. For better agreement, a mesh and time-step independence study should be performed.

Figure 2: Displacement over time for the top-left corner of flexible obstacle (the "dam")

Running the Case

The tutorial case is located at solids4foam/tutorials/fluidSolidInteraction/flexibleDamBreak. The case can be run using the included Allrun script, i.e. > ./Allrun. The Allrun script first executes blockMesh for both solid and fluid domains (> blockMesh -region fluid and > blockMesh -region solid ), and the solids4foam solver is used to run the case (> solids4Foam). Optionally, if gnuplot is installed, the displacement history of the top-right edge of the obstacle Optionally, to create post-processing plots, it is possible to use solidPointDisplacement functionObjects, which will keep track of the specified point during the solution.


[1] E. Walhorn et al. "Fluid-structure coupling within a monolithic model involving free surface flows". Computers & Structures. Vol. 25-26, pp. 2100–2111, 2005.

[2] S. Meduri et al. "A partitioned fully explicit Lagrangian finite element method for highly nonlinear fluid-structure-interaction problems". Internat. J. Numer. Methods Engrg. Vol. 113, pp. 43–64, 2017.

[3] P.B. Ryzhakov et al. "A monolithic Lagrangian approach for fluid-structure interaction problems". Computational Mechanics. Vol. 46, pp. 883–899 , 2010.