Usage
Once installed, VERTEX-CFD relies on two files. The first one is the ‘vertexcfd’ executable, and the second one is the input file for the simulation. After the installation, the executable is located in <PATH TO INSTALLATION LOCATION>/bin/vertexcfd. The input file is case-specific, and there are example case files in vertex-cfd/examples/inputs. In this document, the input file located in vertex-cfd/examples/inputs/incompressible/incompressible_2d_channel.xml will be used as an example case.
Running a simulation
In order to run a simulation in serial, vertexcfd can be called directly as
<PATH TO INSTALLATION LOCATION>/bin/vertexcfd --i=PATH_TO_INPUT_FILE/incompressible_2d_channel.xml
To run in parallel, mpirun is required. An example script for the SLURM scheduler is below:
#!/bin/bash
#SBATCH -N 1
#SBATCH --ntasks-per-node=32
#SBATCH --time=1:00:00
#SBATCH -o output.log
#SBATCH -e error.log
source PATH_TO_ENVIRONMENT_SCRIPT
export OMP_PROC_BIND=true
export OMP_PLACES=threads
mpirun <PATH TO INSTALLATION LOCATION>/bin/vertexcfd --i=<PATH TO INPUT FILE LOCATION>/incompressible_2d_channel.xml
Once the simulation starts, the example output should look like the following:
============================================================================
Time Integration Begin
Thu Mar 31 21:46:09 2022
Stepper = Backward Euler
Simulation Time Range [0, 0.2]
----------------------------------------------------------------------------
Time Step = 1; Order = 1
CFL = 1.000e+00; dt = 6.186e-03; Time = 0.00000e+00
| Nonlinear | F 2-Norm | # Linear | R 2-Norm |
0 6.65e-02
1 2.03e-02 1 6.45e-16
2 4.66e-04 1 4.25e-16
3 5.40e-07 1 5.36e-16
4 3.19e-13 1 6.58e-16
Time step time to completion (s): 5.97e+00
Time Step = 2; Order = 1
CFL = 1.000e+00; dt = 5.644e-03; Time = 6.18583e-03
| Nonlinear | F 2-Norm | # Linear | R 2-Norm |
0 5.73e-02
1 5.72e-03 1 4.68e-16
2 5.40e-05 1 4.01e-16
3 3.47e-09 1 7.18e-16
Time step time to completion (s): 8.96e+00
Time Step = 3; Order = 1
CFL = 1.000e+00; dt = 5.385e-03; Time = 1.18299e-02
| Nonlinear | F 2-Norm | # Linear | R 2-Norm |
0 5.37e-02
1 4.14e-03 1 4.17e-16
2 3.35e-05 1 3.47e-16
3 2.01e-09 1 5.54e-16
Time step time to completion (s): 7.03e-01
... ...
... ...
... ...
... ...
Time Step = 40; Order = 1
CFL = 1.000e+00; dt = 4.853e-03; Time = 1.93731e-01
| Nonlinear | F 2-Norm | # Linear | R 2-Norm |
0 3.57e-02
1 1.15e-03 1 3.89e-16
2 1.68e-06 1 3.90e-16
3 1.66e-12 1 3.20e-16
Time step time to completion (s): 1.73e+00
41 * (dt = 4.852e-03, new = 1.417e-03) Adjusting dt to hit final time.
Time Step = 41; Order = 1
CFL = 1.000e+00; dt = 1.417e-03; Time = 1.98583e-01
| Nonlinear | F 2-Norm | # Linear | R 2-Norm |
0 3.56e-02
1 3.11e-04 1 2.95e-16
2 3.67e-08 1 2.73e-16
3 4.40e-16 1 2.86e-16
Time step time to completion (s): 6.91e+00
----------------------------------------------------------------------------
Total runtime = 1.45e+02 sec
= 2.42e+00 min
= 0.04 hr
Thu Mar 31 21:51:51 2022
Time integration complete.
============================================================================
Once the simulation is completed, the results should be ready for visualization. For the visualization, we suggest using ParaView. However, any visualization software that supports Exodus format should work. The example solution file screenshot visualized in Paraview is shown below: