NAST2D
A Finite Volume Code for Fluid Flow

NAST2D is a FORTRAN90 program which implements the finite volume method to solve for the transient velocity, pressure, and temperature of an incompressible fluid in a variety of 2D flow regions.

NAST2D is a FORTRAN90 version of the program, which was originally written in C.

NAST2D writes graphics files, in particular, a text file containing the stream function at every gridpoint. It can also create "streakline" files, containing the position of marker particles over time.

Usage:

nast2d < input.par > output

• input.par is a "parameter file", that specifies the problem to be solved and associated parameter settings;
• output is the printed output from the program, which you will probably want to have redirected to a file, as illustrated here.

Languages:

NAST2D is available in a C++ version and a FORTRAN90 version.

Related Data and Programs:

BUMP, a FORTRAN90 program which solves a fluid flow problem in a channel including a bump which obstructs and redirects the flow.

HCELL, a FORTRAN77 program which computes the pressure and velocity for a Navier Stokes flow in an "H"-shaped region.

INOUT, a FORTRAN77 program which computes the pressure and velocity for a Navier Stokes flow in a square region with an inlet and an outlet.

MHD_CONTROL, a FORTRAN90 program which tries to control the evolution of an MHD system so that a particular state is achieved.

MHD_FLOW, a FORTRAN90 program which simulates the evolution of an MHD system.

NAST2D_STREAK_MOVIE, a MATLAB program which creates an animation of the streakline data over time.

TCELL, a FORTRAN77 program which computes the pressure and velocity for a Navier Stokes flow in a "T"-shaped region.

TOMS866, a MATLAB library which is the Incompressible Flow Iterative Solution Software;
this library is commonly called IFISS;
this is ACM TOMS algorithm 866.

Reference:

1. Michael Griebel, Thomas Dornseifer, Tilman Neunhoeffer,
   Numerische Simulation in der Stroemungsmechanik,
   Vieweg 1995.
2. Michael Griebel, Thomas Dornseifer, Tilman Neunhoeffer,
   Numerical Simulation in Fluid Dynamics,
   SIAM, 1998,
   This book can be ordered directly from the SIAM web site.
3. http://www.math.jmu.edu/~dpruett/software/
   The NAST2D_F90 web site.

Source Code:

• main.f90, the main program;
• boundary.f90 handles boundary conditions;
• defs.h, an include file that contains the definitions of some constants;
• extras.f90, contains some extra routines to write data to files for visualization by MATLAB;
• init.f90, reads the user input file;
• interfaces.h, an include file that contains the subroutine interface definitions;
• nrtype.f90, reads the user input file;
• surface.f90 handles free boundaries;
• uvp.f90, handles the assembly and solution of the equations that define the state variables;
• visual.f90, routines that write out files for visualization;
• nast2d.sh, commands to compile, link and load the source code;

Examples and Tests:

BACKSTEP is the backward-facing step:

• backstep.par, the parameter file;
• backstep.txt, the output file;

CIRCLE is flow past a circular obstacle:

• circle.par, the parameter file;
• circle.txt, the output file;
• circle.psi, the PSI file, containing the stream function values, which can be displayed by the NAST2D_CONTOUR MATLAB routine;

CONVECT is buoyancy flow with heated side walls:

• convect.par, the parameter file;
• convect.txt, the output file;

DAM is a free boundary problem with a breaking dam:

• dam.par, the parameter file;
• dam.txt, the output file;

DCAVITY is the driven cavity:

• dcavity.par, the parameter file;
• dcavity.txt, the output file;

DROP follows the splash of a drop of liquid:

• drop.par, the parameter file;
• drop.txt, the output file;

FLTRAP is a buoyancy flow with obstacles:

• fltrap.par, the parameter file;
• fltrap.txt, the output file;

MOLDING is a flow based on injection molding:

• molding.par, the parameter file;
• molding.txt, the output file;

RAYLEIGH is a buoyancy flow with heated upper and lower walls:

• rayleigh.par, the parameter file;
• rayleigh.txt, the output file;

WAVE is a free surface flow over a step:

• wave.par, the parameter file;
• wave.txt, the output file;

You can go up one level to the FORTRAN90 source codes.