20/10/2004: Release 0.6.0

First the good news:

Diffusion equations with complex boundary conditions can now be solved
in 3D!

Now the bad news:

Variable density support is broken in this version (use 0.3.0 if you
need it). The reason is that this part of the code needs to be
reviewed/generalised to make sure it does the right thing.

The main changes/improvements in this version are:

- Support for diffusion equations in 3D complex geometries
- Flexible boundary conditions on embedded solid surfaces for
  diffusion equation in parameter files (see the tutorial)
- Updated tutorial and reference manual
- An initial implementation of a shallow-water 2D and 3D hydrostatic
  ocean model with semi-implicit Coriolis source terms and barotropic
  equation (multigrid for Helmoltz equation)
- Support for different types of simulations (ocean and incompressible
  Euler/NS for the moment)
- Support for multiple tracers
- Much improved interpolation of variables
- New consistent pressure correction formulation (which works with
  momentum source terms near boundaries)
- MPI configuration reworked (uses mpicc): tested with mpich and
  lam-mpi
- Bounding boxes for PPM output: allows to select a limited area for
  PPM output
- Optional binary file format (4 to 5 times faster file read)

Minor bug corrections and improvements:

- pkgconfig support
- MacOSX support
- Bug fix for 64 bits machines
- Relaxed constraints on refinement (still needs work)
- External library links in GfsFunction
- Short keyword support
- Lambda2 criterion of Jeong and Hussain (for vortex detection)
- etc...

20/05/2004: Release 0.3.0

Quite a lot has happened since 0.2.0. The main changes/improvements are:

- On systems supporting dynamic linking, functions of space and time
can be used instead of constants for most objects which require a
numerical argument. This is particularly useful for initialisation
(each field can be set using functions of space and time) where almost
any mathematical description of the initial conditions can be written
directly in the parameter file (no need to create a custom module
etc...). The same mechanism can also be used to define the initial
refinement of the grid (i.e. specify the mesh density as a
mathematical function directly in the parameter file) or variable
source terms.

- The boundary condition subsystem has been entirely revamped. It is
now possible to define complex boundary conditions by combining
independent boundary conditions (Dirichlet, Neumann etc...) for each
variable. Dynamic functions can be used within this framework which
allows for variable in space (e.g. profiles) and in time boundary
conditions.

- The code now includes a multigrid semi-implicit diffusion solver. It
can work together with embedded solid boundaries in 2D but not yet in
3D. It is possible to accurately specify the boundary conditions
(Dirichlet or Neumann) for the diffused variable on the solid
boundaries. All this allows for the solution of advection-diffusion
equations such as incompressible Navier-Stokes. Due to the stability
of the semi-implicit scheme it is also possible to solve pure Stokes
flows with no restriction on the time step.

- The adaptive engine has been rewritten. It is now possible to
control the maximum size of the simulation. When this maximum size is
reached, the algorithm will optimally distribute this maximum number
of cells so that the adaptive criterion is minimized.

- Note that the parameter file arguments of several objects have
changed (GfsAdapt in particular), so that full parameter file
compatibility with 0.2.0 is not guaranteed.

- Volume of Fluid or standard Godunov advection schemes can now be
selected in parameter files.

- New object outputs the pressure and viscous forces exerted on the
embedded solid boundary.

- The pressure is now properly scaled.

- Plus a large number of bug fixes, small improvements etc...

Have a look at the ChangeLog for details.

08/01/2003: Release 0.2.0

This new release of Gerris includes a number of new features as well
as some major code restructuring. 

The GTS library version 0.7.1 is required. It includes major
improvements for boolean operations between surfaces which greatly
improve the robustness of the treatment of solid boundaries within
Gerris.

The major changes are listed below. For a detailed summary see the
ChangeLog.

New features:

- Support for the variable density incompressible Euler equations.

- Support for user-defined source terms for any variable. Gaussian
  tracer source terms and constant source terms (e.g. acceleration of
  gravity in momentum equation) are provided.

- Base domain does not have to be cubic anymore. Independent length
  scales can be provided for each dimension.

- Module for OpenDX allowing direct import of Gerris simulation files.

- Updated documentation and tutorial: section about user-defined
  extension modules for initial conditions.

- Support for dynamic allocation of additional cell variables
  i.e. extension modules can dynamically add additional variables if
  needed.

- Automatic compilation and installation of 2D and 3D versions. 

- Preliminary implementation of a second-order Volume Of Fluid (VOF)
  advection scheme.

- A new GfsAdaptNotBox class can be used to specify parts of the
  domain which do not need to be refined. This is particularly useful
  for implementing absorbing outflow conditions.

Improvements and restructuring:

- Improved adaptive refinement algorithm.

- Restructuring of the test suite.

19/06/2002: Release 0.1.0

Hi all,

I am glad to announce the first "official" release of Gerris.

It needs the latest version of GTS (0.6.0) to compile.

A major change since last month is the addition of "dynamic adaptive
mesh refinement" i.e. the distribution of cells changes according to
what is happening to the solution. Have a look at the gallery on the
web site for a graphical illustration.

here:

http://gfs.sourceforge.net/gallery.html

and here (at the bottom of the page):

http://gfs.sourceforge.net/tangaroa.html

I also wrote a short tutorial which should help you get started with
the code (available online and in the distribution in doc/tutorial).

http://gfs.sourceforge.net/tutorial/tutorial1.html

Any feedback is of course welcome,

Enjoy,

Stephane

11/12/2001: Inital CVS checkin
01/08/2001: Initial setup
 LocalWords:  GfsAdaptNotBox
