Example 339: Solving 3d Navier-Stokes equations

Solving the 3d non-dimensional Navier-Stokes pipe flow.


The comfile run by this example is as follows:

# Example 339 - Solving 3d non-dimensional Navier Stokes flow in a pipe

fem def para;r;pipe3d;example # Define the array parameters to allow Voronoi mesh use

fem def coord 3,1             # Define 3d rectangular Cartesian coordinates
fem def node;r;pipe3d;example # Define the Delaunay/Voronoi nodes
fem def base;r;pipe3d;example # Define 3d simplex basis functions 
fem def elem;r;pipe3d;example # Define 3d Delaunay elements
fem up dela                   # Update the Delaunay triangulation to ensure Delaunayism
fem def mesh;r;pipe3d;example # Define a Voronoi mesh to be calculated
fem def equa;r;pipe3d;example # Define equation type. This will be a time integration,
                              # Navier Stokes equation, of a general type, solved 
                              # using finite volumes.       
fem def mate;r;pipe3d;example #  Define material. This is unimportant as the equations
                              # solved are non-dimensional, ie only depend on the 
                              # Reynolds number. These parameters are used only for
                              # conversion back to dimensional form. This has not
                              # been implemented yet.
fem def init;r;pipe3d;example # Define initial conditions. At one end of the pipe will
                              # be a specified inlet velocity (Type inlet), while at the
                              # other end will be an outlet boundary condition. All other
                              # Bc's will be a Wall with zero velocity. Be sure to use
                              # duct flow outlet boundary conditions as they are superior
fem def solv;r;pipe3d;example # Define the solution parameters. 
                              # Always use automatic stepping unless stupid.
                              # As the mesh is fixed, you want to use a sparse LU 
                              # solver (only needs to be factorised once). 
                              # Use QUICK advection (best for steady state cases).
                              # The Courant number scales the maximum allowable
                              # time step by a factor of safety, should be between
                              # 0.3 and 0.7.
fem solv                      # Solve to steady state.

Additional testing commands:

fem list node solution

Files used by this example are:

Name             Modified     Size

example_339.com 20-Nov-2001 2.2k pipe3d.ipbase 10-Apr-2000 2.1k pipe3d.ipelem 10-Apr-2000 265k pipe3d.ipequa 26-May-2003 1.4k pipe3d.ipinit 13-Mar-2001 31k pipe3d.ipmate 10-Apr-2000 684 pipe3d.ipmesh 06-Nov-2001 978 pipe3d.ipnode 10-Apr-2000 33k pipe3d.ippara 12-Nov-2002 5.6k pipe3d.ipsolv 13-Apr-2007 2.7k test_output.com 10-Apr-2000 23

Download the entire example:

Name                      Modified     Size

examples_3_33_339.tar.gz 14-Apr-2007 21k

Testing status by version:

StatusTestedReal time (s)
cm_aix_mp_1SuccessThu Apr 1 10:11:32 200426
cm_aix_mp_2SuccessThu Apr 1 12:00:03 200418
cm_aix_mp_4SuccessThu Apr 1 12:03:09 200417
cm_aix_mp_8SuccessThu Apr 1 12:45:10 200416
cm_n32_mp_1SuccessThu Sep 1 01:37:54 200528
cm_n32_mp_2SuccessThu Sep 1 03:22:07 200528
cm_n32_mp_4SuccessTue Aug 16 13:43:03 200525
cm_n32_mp_8SuccessTue Aug 16 13:43:44 200529
i686-linux
cmSuccessSun Mar 6 00:01:52 20161
cm-debugSuccessSat Mar 5 00:11:58 20164
mips-irix
cmSuccessSun Aug 19 01:41:16 200711
cm-debugSuccessWed Aug 15 01:42:48 200741
cm-debug-clear-mallocSuccessSat Aug 18 01:51:04 200744
cm-debug-clear-malloc7SuccessMon Aug 20 01:47:17 200745
cm64SuccessSun Aug 19 01:42:29 200711
cm64-debugSuccessTue Aug 21 01:43:45 200745
cm64-debug-clear-mallocSuccessThu Apr 1 10:13:47 200421
rs6000-aix
cmSuccessWed Mar 4 01:08:02 20091
cm-debugSuccessMon Mar 2 01:11:48 200912
cm64SuccessWed Mar 4 01:08:03 20092
cm64-debugSuccessTue Mar 3 01:16:45 200914
x86_64-linux
cmSuccessSun Mar 6 00:01:03 20160
cm-debugSuccessSat Mar 5 00:01:47 20162

Testing status by file:


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Input last modified: Fri Apr 13 10:32:43 2007


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