Dam break problem with thin film that cause pressure drop

Update: July 1, 2017
OpenFOAM 4.x

Case directory

$FOAM_TUTORIALS/multiphase/interFoam/ras/damBreakPorousBaffle

Summary

Model geometry Model geometry

We compute the dam-break problem (collapse of the water column) for one second. The ceiling of the analysis domain (domain atmosphere) is assumed to be open, and the left wall, right wall and floor are assumed to be under no-slip conditions. The calculation is performed as a two-dimensional problem with a single mesh in the Z direction.

The direction of gravity acceleration is defined in the file "constant/g" as follows.

dimensions      [0 1 -2 0 0 0 0];
value           (0 -9.81 0);

The properties of the thin film that cause pressure drop are specified in the file "0/p_rgh" as the boundary conditions for the pressure on the front and back of the region as follows.

porous_half0
{
    type            porousBafflePressure;
    patchType       cyclic;
    D               1000;
    I               500;
    length          0.15;
    jump            uniform 0;
    value           uniform 0;
}

porous_half1
{
    type            porousBafflePressure;
    patchType       cyclic;
    D               1000;
    I               500;
    length          0.15;
    jump            uniform 0;
    value           uniform 0;
}

The meshes are as follows, and the number of mesh is 2268.

Mesh Meshes
Meshes (front view) Meshes (front view)

The calculation result is as follows.

Volume ratio of water (alpha.water)
Volume ratio of water at initial time (alpha.water) Volume ratio of water at initial time (alpha.water)
Volume ratio of water at 0.6 sec (alpha.water) Volume ratio of water at 0.6 sec (alpha.water)

We can see that the liquid goes into the thin film area while the liquid velocity is decreasing.

Commands

cp -r $FOAM_TUTORIALS/multiphase/interFoam/ras/damBreakPorousBaffle damBreakPorousBaffle
cd damBreakPorousBaffle

blockMesh
setFields
createBaffles -overwrite
interFoam

paraFoam

We create the internal walls for the thin film with createBaffles utility.

Calculation time

1 minute 2.74 seconds *Single, Inter(R) Core(TM) i7-2600 CPU @ 3.40GHz 3.40GHz