This changelog is focused on changes related to our tagged releases. The intent is to document all notable changes, with most recent listed first.


  • shift default interpolation type for StructuredGrids from “simple” to “linear”

[4.1.0] - 2022-02-23

Meta Change


  • Default install location $HOME/dgdinst –> $HOME/gdtkinst

  • Specification of cfl_schedule in transient code is now of the form:

      config.cfl_schedule = {{0.0,0.5}, {0.5e-3,1.0}, {2.0e-3,10.0}}

    In each pair, the first number is time and the second number is CFL value.

  • For specialist post-processing, class BlockFlow renamed to FluidBlockLite to better represent its intent. FluidBlockLite is used in post-processing to read, interact, manipulate fluid data at a block level. The “lite” refers to the fact that it is not a full-blown FluidBlock object as implemented in the code internals.

  • prep-gas now selects the CompositeGas when requesting a thermally perfect gas model. This uses the the unified gas model machinery built in 2021, and begins the deprecation of the special-purpose implementations.

  • Lua version embedded in code upgraded: 5.1.4 –> 5.4.3


  • Clean up on MPI exit paths to avoid hanging processes when the gas dynamics encounters adverse situations.
  • Fixed bug in computation of transport properties and update of sound speed at a boundary interface for the special user-defined boundary interface effect.


  • Control point form as option for algebraic grid generation on structured grids See technical note:

  • Conical inflow as option to supersonic inflow, constant flux and shock-fitting boundary conditions. See example in: examples/eilmer/2D/nozzle-conical-ideal

  • GridArray class added to separate the role of grid division out from FBArray.

  • FBArray can now be constructed from an array of grid objects. See example: examples/eilmer/2D/shear-layer-periodic/psl-gridArray.lua

  • An option to compute mixture averaged diffusion coefficients from the binary diffusion coefficients of all interacting pairs in the mixture.

  • A more robust calculation of wall distances for use in the Spalart-Allmaras turbulence model.

  • e4monitor program now has option to run in foreground mode to start a simulation:

      $ e4monitor --job=cone20 --startup=1 --period=1 --command="mpirun -np 8 --oversubscribe e4mpi --run --job=cone20"
  • CubePatch geometry object. CubePatch is like SpherePatch but produces a flat (square) surface with edge length 2a.

  • Meta-data at Eilmer start-up now include more information: Revision-date, Build-date and Profiling.

  • RuledSurface geometry object.