NaSt3DGP is an implementation of a solver for the incompressible Navier-Stokes equations in three dimensions. It is based on a Chorin type projection method.
The main features of NaSt3DGP are:
Much emphasis is laid on the point that also complex problems, such
as flows around complicated geometries, can be defined in a clear
and easy way to rapidly obtain numerical results. To this end, there
is a simple macro-language with a few but powerful and meaningful
key-words to describe the flow configuration. This allows the user
- spatial discretization by 2nd order finite differences on a rectangular, non-uniform, staggered mesh
- convective term: higher order upwind schemes (VONOS, SMART), central differences (2nd order), simple upwind (1st order)
- 2nd order Adams-Bashforth scheme for the time discretization
- boundary conditions: slip, no slip, periodic, inflow, outflow (Neumann, convective, natural)
- (passive) advection-diffusion transport model for concentration of species
- Boussinesq advection-diffusion transport model for temperature
- handling of complex geometries by a simple cell decomposition/enumeration technique
- BiCGStab and SOR iterative solver for pressure Poisson equation (lexicographical, red-black, colored red-black)
- parallelization by means of 3D domain decomposition with good communication/work ratio heuristics
- parallelization based on MPI
- implemented in C++
- various import/export formats, including architecture independent ones and for the VTK graphics library
- macro language for easy problem description
NaSt3DGP is essentially based on the code described in the book:
- build complex geometries by union, intersection, subtraction
of CSG (Constructive Solid Geometry) primitives using shape
parameters independent on the discretization
- describe the computational mesh in a simple way
- define various parameters, e.g. Reynolds number, stopping
value for iterative solver, upwind parameter, etc.
Griebel/Dornseifer/Neunhoefer, Numerische Simulation in der Strömungsmechanik, Vieweg Verlag (1995)
Griebel/Dornseifer/Neunhoefer, Numerical Simulation in Fluid Dynamics, SIAM Philadelphia (1998), (english version)
The software package NaSt3DGP is available for download free of charge for academic research and non-commercial use. Please refer to the Download section for details on licensing and how to obtain the software.
The NaSt3DGPF package is an extension of NaSt3DGP including additional features. In particular, free surface flows and surface tension are implemented employing a level-set approach. If you are interested in licensing NaSt3DGPF, please visit the NaSt3DGPF website for further details.