Supported output formats

Eddylicious supports several file formats for outputting the generated inflow fields. The choice of the file format is usually dictated by the CFD solver.

The HDF5 file format

HDF5 is a file format specifically developed for storing large scientific datasets. More details regarding HDF5 can be found here.

In HDF5 data can be sorted into groups. The data itself is stored in the form of datasets. One can think of datasets as of multidimensional arrays.

Let \(N_p\) be the number of points at which the inflow fields are generated and \(N_t\) the amount of time-values for which the inflow fields are generated. Eddylicious creates the following datasets inside the HDF5 file.

  • points, \(N_p \times 3\) — the points associated with the values of the inflow fields. The three columns represent the \(x\), \(y\), and \(z\) coordinates respectively.
  • times, \(N_t \times 1\) — the time values associated with the inflow fields.
  • velocity, \(N_t \times N_p \times 3\) — the values of the velocity field. The first index is associated with time, the second with the available points and the third one with the components of the velocity field. Same order as in points applies.

The following parameters need to be provided in the configuration file in order to output the velocity fields in the HDF5 file format.

writer          hdf5
writePath       path to the where the database will be stored
hdf5FileName    name of the hdf5 file

OpenFOAM native format

This is natively supported by OpenFOAM. In order to read in boundary data from the hard-drive OpenFOAM has a special boundary conidtion called timeVaryingMappedFixedValue. This boundary condition expects a folder called boundaryData/\<patchname\> to be located in the constant directory of the case. Inside the folder a file named points should reside. This file provides a list of the points where the boundary data is available. The boundary data itself resides in folders named as the time-value associated with the data. The data for each available field is stored in its own file named identically to the internal name of the field in OpenFOAM (for instance U for the velocity field). The format of each such file is quite similar to the The foamFile format but has some additional headers.

The following parameters need to be provided in the configuration file in order to output the velocity fields in the OpenFOAM native format.

writer          ofnative
writePath       /path/to/OpenFOAM/case
inletPatchName  name of the inlet patch