Chapter 5

FieldConvert is a utility embedded in Nektar++ with the primary aim of allowing the user to convert the Nektar++ output binary files (.chk and .fld) into a format which can be read by two common visualisation softwares: Paraview (.vtu format) or Tecplot (.dat format). FieldConvert also allows the user to manipulate the Nektar++ output binary files by using some additional modules which can be called with the option -m which stands for module. Note that another flag, -r (which stand for range) allows the user to specify a sub-range of the domain on which the conversion or manipulation of the Nektar++ output binary files will be performed.

Almost all of the FieldConvert functionalities can be run in parallel if Nektar++ is compiled using MPI (see the installation documentation for additional info on how to implement Nektar++ using MPI). 1

 5.1 Convert .fld / .chk files into Paraview, VisIt or Tecplot format
 5.2 Range option -r
 5.3 FieldConvert modules -m
  5.3.1 Smooth the data: C0Projection module
  5.3.2 Calculate Q-Criterion: QCriterion module
  5.3.3 Sum two .fld files: addFld module
  5.3.4 Combine two .fld files containing time averages: combineAvg module
  5.3.5 Concatenate two files: concatenate module
  5.3.6 Equi-spaced output of data: equispacedoutput module
  5.3.7 Extract a boundary region: extract module
  5.3.8 Compute the gradient of a field: gradient module
  5.3.9 Extract a plane from 3DH1D expansion: homplane module
  5.3.10 Inner Product of a single or series of fields with respect to a single or series of fields: innerproduct module
  5.3.11 Interpolate one field to another: interpfield module
  5.3.12 Interpolate scattered point data to a field: interppointdatatofld module
  5.3.13 Interpolate a field to a series of points: interppoints module
  5.3.14 Isocontour extraction: iscontour module
  5.3.15 Show high frequency energy of the Jacobian: jacobianenergy module
  5.3.16 Extract mean mode of 3DH1D expansion: meanmode module
  5.3.17 Project point data to a field: pointdatatofld module
  5.3.18 Print L2 and LInf norms: printfldnorms module
  5.3.19 Computes the scalar gradient: scalargrad module
  5.3.20 Scale a given .fld: scaleinputfld module
  5.3.21 Time-averaged shear stress metrics: shear module
  5.3.22 Boundary layer height calculation: surfdistance module
  5.3.23 Calculate vorticity: vorticity module
  5.3.24 Computing the wall shear stress: wss module
  5.3.25 Manipulating meshes with FieldConvert
 5.4 FieldConvert in parallel
 5.5 Processing large files in serial
  5.5.1 Using the nprocs and procid options
  5.5.2 Using the –part-only and –part-only-overlapping options