tcell


tcell, a Fortran77 code which solves the time-dependent Navier Stokes equations in a two dimensional region called the "T Cell", by Hyung-Chun Lee.

As time increases, other flow parameters may be varied as well. For this code, the flow parameter that can vary is the magnitude of the inflow specified at the left boundary. The program stores the results of each timestep in a file. Each solution may be thought of as a "snapshot" of the gradual evolution of the flow field over time. In a typical run, 500 such files might be created.

A collection of snapshot files may be analyzed to seek a small underlying basis of fundamental flows. This basis may be used to approximate the entire set, or indeed to generate a reduced basis program that can quickly and cheaply compute new flow solutions whose flow parameters vary in small ways from those of the original set.

The "T-Cell" region is a T-shaped region contained in a subset of the unit square [01]x[01]. The top half of the region is a channel open to the left and right, with a rectangular recess in the bottom. The left channel opening extends from [0.0,0.5] to [0.0,1.0], and the right channel from [1.0,0.5] to [1.0,1.0]. The recess is a square, whose bottom extends from [0.25,0.0] to [0.75,0.0], and which extends upward to meet the channel.

             +--------------------+
             +--------------------+
            ->                      ->
      Inlet --->      Channel       --->  Outlet
            ->                      ->
             +-----+          +---+
             +----+|  Recess  |+--+
                  ||          ||
             Void ||          || Void
                  |+----------+|
                  +------------+
      
The grid can be thought of as being generated by a uniform 81 by 81 uniformly spaced grid of nodes, from which the nodes corresponding to the two voids have been deleted. This leaves 4,961 nodes. These nodes are organized into 2400 6-node triangular elements which are quadratic in velocity and linear in pressure.

Usage:

tcell
runs the program

Author:

Hyung-Chun Lee,
Ajou University, Korea,
in collaboration with Max Gunzburger and John Burkardt.

Licensing:

The computer code and data files described and made available on this web page are distributed under the MIT license

Languages:

tcell is available in a Fortran77 version and a MATLAB version.

Related Data and Programs:

tcell_test

BUMP, a Fortran90 program which seeks the appropriate channel inflow and bump shape which will cause the flow to most closely match a given downflow profile.

CHANNEL, a Fortran77 program which seeks the appropriate channel inflow which will cause the flow to most closely match a given downflow profile.

CVT_BASIS_FLOW, a Fortran90 program which extracts dominant solution modes from a set of flow solutions using CVT methods.

HCELL, a Fortran77 program which solves the Navier Stokes equations in the H-Cell region.

INOUT, a Fortran77 program which solves the Navier Stokes equations in the "In-Out" region.

MHD_CONTROL, a Fortran90 program which controls the evolution of an MHD system so that a particular state is achieved.

MHD_FLOW, a Fortran90 program which simulates the evolution of a system governed by the equations for magnetohydrodynamics.

NAST2D, a C++ program which solves the 2D Navier Stokes fluid flow equations

NAST2D_F90, a Fortran90 program which uses the finite volume method to set up and solve the 2D incompressible Navier Stokes equations with heat.

POD_BASIS_FLOW, a Fortran90 program which extracts dominant solution modes from a set of flow solutions using POD methods.

TCELL_FLOW, a dataset which contains 500 successive flow solutions of the T-Cell problem.

TCELL_FLOW_MOVIE, an animation of a time simulation of the flow computed by TCELL.

TCELL_MASS, a Fortran77 program which computes the mass matrix for the T-Cell problem.

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. Max Gunzburger,
    Finite Element Methods for Viscous Incompressible Flows,
    A Guide to Theory, Practice, and Algorithms,
    Academic Press, 1989,
    ISBN: 0-12-307350-2,
    LC: TA357.G86.
  2. John Burkardt, Max Gunzburger, Hyung-Chun Lee,
    Centroidal Voronoi Tessellation-Based Reduced-Order Modelling of Complex Systems,
    SIAM Journal on Scientific Computing,
    Volume 28, Number 2, 2006, pages 459-484.

Source Code:


Last revised on 15 December 2023.