Post-processing
The Channel3D program outputs two types of files:
| Data type | Type | Output frequency |
|---|---|---|
| Instantaneous field snapshots | Binary | Every nsave timesteps (specified in input file) |
| Statistics | Plain text file | Every nstats timesteps (specified in input file) |
Instantaneous field snapshots
This data is in binary format and can be read by the Python function read_field in the file_io.py module. Similar binary output files from the original (non-IB) Channel3D solver can be read by the same function with the original_format=True argument. The read_field function returns a dict containing the following keys:
| Key | Type / Shape | Included if original_format=True? |
Description |
|---|---|---|---|
x, y, z |
1D array (Nx, Ny, Nz) | Yes | Cell face coordinates in each spatial direction |
xm, ym, zm |
1D array | Yes | Cell center coordinates in each spatial direction (excluding ghost cells) |
xg, yg, zg |
1D array | Yes | Cell center coordinates in each spatial direction (including ghost cells) |
U |
3D array (len(x), len(yg), len(zg)) | Yes | Velocity components in the x direction |
V |
3D array (len(xg), len(y), len(zg)) | Yes | Velocity components in the y direction |
W |
3D array (len(xg), len(yg), len(z)) | Yes | Velocity components in the z direction |
P |
3D array (len(xg), len(yg), len(zg)) | Yes | Pressure field |
Hu_interior |
3D array | No | Indicator field for the interior domain at the U locations |
Hv_interior |
3D array | No | Indicator field for the interior domain at the V locations |
Hw_interior |
3D array | No | Indicator field for the interior domain at the W locations |
t |
scalar | No | Simulation time |
dt |
scalar | No | Time step size |
dpdx |
scalar | No | Mean streamwise pressure gradient in x-direction |
nu |
scalar | No | Kinematic viscosity |
xb, yb, zb |
1D arrays | No | Immersed boundary point coordinates |
nxb |
integer | No | Number of IB points in x |
nzb |
integer | No | Number of IB points in z |
fb |
1D array (3 times Nb,) | No | Force at IB points: [fx..., fy..., fz...] |
ub |
1D array (3 times Nb,) | No | Velocity at IB points: [ux..., uy..., uz...] |
sb |
1D array | No | Surface area around each IB point |
normals |
1D array (3 times Nb,) | No | Surface normals: [nx..., ny..., nz...] |
tangents_1 |
1D array (3 times Nb,) | No | First tangent vectors: [tx1..., ty1..., tz1...] |
tangents_2 |
1D array (3 times Nb,) | No | Second tangent vectors: [tx2..., ty2..., tz2...] |
Statistics
Coming soon.