Palabos Release 1.1

We’re glad to announce the 1.1 release of Palabos which, as usual, comes with important new models and features:

  • A free-surface model for binary fluid systems with infinite viscosity ratio (you may already have seen the movies of the breaking dam on the Palabos web page).
  • A parallel implementation of the marching-cube algorithm to export iso-surfaces.
  • An off-lattice boundary condition for advection-diffusion systems.
  • A Java binding for the Palabos library.

Get the newest release from the download page.

New Model: Free-Surface flow
Palabos already came with two multi-phase models (Shan/Chen and He/Lee). This new release now provides an efficient implementation of binary fluid systems with infinite viscosity ratio, through a free-surface model. The low-viscosity fluid is neglected here, and a volume-of-fluid approach used to trace the interface of the remaining fluid. Andrea implemented this model for us.
As usual, the implementation of this model is fully parallel, has excellent scaling properties, and can be conveniently combined with existing Palabos ingredients (e.g. Bounce-Back boundary treatment, VTK output, etc.).
In lieu of a documentation, a complete example is provided (examples/showCases/breakingDam3d.cpp).
Check out the new movies of the dam break problem on the Palabos web page!

Marching-Cube algorithm for surface post-processing
When you run Palabos on a large parallel machine, you run into the typical post-processing bottleneck: the produced data files are too large to be reasonable treated with Paraview, for example. For this reason, Palabos progressively introduces internal post-processing abilities that are fully parallel and therefore not subject to this bottleneck.
In this release, a parallel marching-cube implementation is provided which computes iso-surfaces and exports them in the STL format (see examples in examples/codesByTopic/marchingCube).
One particularly interesting application of the marching-cube algorithm is its ability to export the fluid surface from Palabos’ new free surface model. You can for example simulate a big river system on a parallel machine, and export the shape of the free surface at frequent intervals without running into an I/O bottleneck.

Off-lattice boundary condition for advection-diffusion systems
Since Version 1.0, Palabos provides an implementation of off-lattice boundaries for fluids: you can read a geometry description from an STL file, and automatically set up a fluid system, with inlets and outlets, in parallel, with sparse memory representation. A similar off-lattice model has now been implemented for the advection-diffusion equation, and it has become possible to simulate thermal convection in a general geometry.

New Java programmer interface
Additionally to the already existing Python interface, Palabos now offers a Java interface, implemented for us by Yann. Java is a compiled language and was implemented in a different spirit than the Python interface. The Python binding was developed to add interactive programming and rapid prototyping to Palabos’ programming interface. From the Java binding we rather expect to open up Palabos to a larger audience of programmers unfamiliar with C++, and to more easily integrate it with other software libraries.