Overview🔗
- Solver: pimpleFoam
- 3D decay of homogeneous incompressible isotropic turbulence (HIIT) based on the reference [10]
- Mesh and initial velocity field created using the
createBoxTurb
utility - Energy spectrum calculated using the
energySpectrum
function object - $FOAM_TUTORIALS/incompressible/pimpleFoam/LES/decayIsoTurb
The domain comprises a 3D cube with a side length is \(L = 0.09 \times 2 \pi\) m:
Cyclic conditions are applied to all patches.
Measurements were performed at a Reynolds number of 34000, based on a length scale of 5.08 cm and velocity of 10 m/s. This suggests a laminar viscosity of
\[\nu = \frac{|\u_0| L}{\mathrm{Re}} = \frac{10 \times 0.0508}{34000} = 1.5 \times 10^{-5} m^2/s\]Turbulence quantities were measured at non-dimensional times of:
\[t^* = \frac{t |\u_0|}{L} = 42, 98, 171,\]equating to dimensional times of 0.213, 0.498 and 0.869 seconds. By basing the initial condition on the 0.213s data, the comparisons can be performed at 0.285s and 0.656s.
Mesh🔗
The block mesh is created using the createBoxTurb
utility, with the
-createBlockMesh
option
Boundary conditions🔗
Cyclic conditions are applied to all patches
Initial conditions🔗
An initial velocity field was created using the createBoxTurb
utility.
This is based on the procedure described by Saad et. al.
[61], using the turbulence energy spectra at
\(t^*= 42\).
Results🔗
These are initial results and further details will be available shortly
An animation for a 256x256x256 box showing the velocity field, and turbulence structures using the Q criterion shows the decay of the complex flow field.
An example of the decay profiles for the WALE LES model shows good agreement.
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The grey region represents the wave numbers above the Nyquist limit for this mesh.