Visualisation

zCFD by default will output data in VTK format. This format can be read directly by many post-processing tools including ParaView by Kitware.

Output in other formats is also possible, including TECPLOT and EnSight as follows:

VTK Output

By default, zCFD will output data in VTK format. To explicitly force VTK output, use the following option in the ‘write output’ part of the control dictionary:

'write output' : {
                    # Output format
                    'format' : 'vtk',

EnSight Output

To output in EnSight format, use the following option in the ‘write output’ part of the control dictionary:

'write output' : {
                    # Output format
                    'format' : 'ensight',

Native HDF5 Output

To output in HDF5 format (the native format for zCFD), use the following option in the ‘write output’ part of the control dictionary:

'write output' : {
                    # Output format
                    'format' : 'native',

ParaView Catalyst Scripts

ParaView provides a powerful yet lightweight interface that allows parallel processing of simulation data during programme execution called ParaView Catalyst. This is driven by scripts (Python files) that can be called when data is output:

'write output' : {
                    # Output format MUST be VTK
                    'format' : 'vtk',
                    # The scripts should be in the same directory as the input files
                    'scripts' : ['paraview_catalyst1.py','paraview_catalyst2.py']

ParaView Client

To download the free ParaView software for visualising VTK format data on the local device, just visit the Paraview website.

ParaView Client-Server

In addition to running entirely locally on a device, ParaView can interface to a remote server. This allows users to run ParaView to access data that is held (and processed) on a different computer, potentially running larger simulation tasks that would be possible on the local machine. This also means that there is no need to transfer the large output files back to a local machine for post-processing. The remote machine can easily be set up to run a ParaView Server in parallel - meaning that very large post-processing jobs can be run quickly.

ParaView Server

To download and install ParaView Server, you can either use the version on the main ParaView website and follow the instructions here.

Alternatively or else use the version bundled with zCFD. The ‘pvserver’ included in the zCFD distribution includes plugins for reading the zCFD HDF5 mesh format directly.

To start a ParaView Server on your computer within the zCFD environment run:

> pvserver

ParaViewConnect

ParaviewConnect is a helper utility for connecting to remove ParaView servers. It reduces the complexity of setting up the required ssh connections and works well with zCFD. More information and installation instructions can be found on the Github page.

Jupyter Notebooks

We also recommend the use of Jupyter Lab for post-processing zCFD runs. This is one of the easiest ways to use Python, via an interactive notebook on your local computer. The notebook is a locally hosted server that you can access via a web-browser. Jupyter is included in the zCFD distribution and notebooks for visualising the residual data will automatically be created when you run a zCFD case. In addition there are several example notebooks available in the zPost.

To automatically start up notebook server on your computer within the zCFD environment run:

> start_lab