Update: June 1, 2017

$FOAM_TUTORIALS/DNS/dnsFoam/boxTurb16

The flow in a cube that all six sides are periodic boundaries will be solved until 10 seconds **without using a turbulence model**. The turbulence generated by the utility boxTurb is used as the initial condition, and after the calculation, the enstrophy is calculated with the utility postProcess.

The mesh and initial conditions are as follows. The analysis area is divided into 16 equal parts in each of the X, Y, and Z directions as mesh.

Meshes

Initial velocity (U)

After the potential flow calculation, the enstrophy is calculated and output. To visualize the enstrophy, check the "enstrophy" in the "Properties" tab in ParaView.

Check "enstrophy"

The calculation result is as follows.

Absolute value of flow velocity (U)

Absolute value of flow velocity at 10 seconds (U)

Pressure at 10 seconds (p)

Enstrophy at 10 seconds

Since all boundary surfaces are periodic boundaries, momentum is conserved throughout the system and the flow does not decay.

cp -r $FOAM_TUTORIALS/DNS/dnsFoam/boxTurb16 boxTurb16

cd boxTurb16

blockMesh

boxTurb

dnsFoam

postProcess -func enstrophy

paraFoam

cd boxTurb16

blockMesh

boxTurb

dnsFoam

postProcess -func enstrophy

paraFoam

The boxTurb generates the initial conditions, and the postProcess calculates the enstrophy.

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