Example 2: automatic preparation of a series of Flux projects ready to be solved


The objective is to study 3 specific configurations of a parameterized device.

Example description

The studied device is a simple geometrical figure (quadrilateral) defined using 6 parameters: X1, Y1, X2, Y2, X3, Y3.

This command file could be used to create different Flux projects in 2D.


The process includes the following stages:

Stage Description Context
1 Preparing a Flux project which contains the base geometry Flux
2 Saving in a command file the sequence of the geometry modification with mesh rebuilding Flux
3 Modification of the previous command file using the PyFlux language Text editor
4 Executing this file to test it Flux

Stage 1

To build the basic geometrical figure on which the modifications will be carried out, to carry out the following procedure:

Step Action
1 Open a new Flux project

Build the geometry:

  • create the following 6 geometric parameters:

    X1 = 20, Y1 = 0, X2 = 0, Y2 = 10, X3 = 20, Y3 = 10

  • create the following 4 points:

    (0, 0); (X1, Y1); (X2, Y2); (X3, Y3);

  • create the 4 lines to close a rectangle with these 4 points
  • build the faces

Mesh the device:

  • modify the value of the MEDIUM Mesh line (value: 1 mm)
  • assign the MEDIUM Mesh line to the 4 points
  • mesh the faces
4 Save the project under the name BASE.FLU

Stage 1: final result

The project BASE.FLU contains:

  • 6 parameters,
  • 4 points ((3 are parameterized))
  • 4 lines (segments)
  • 1 meshed face

Stage 2

To save in a command file the sequence of modification:

Step Action
1 Create a command file ModifParam.py

Carry out the modification actions:

  • delete the mesh (to enable the geometrical modification)
  • modify the value of a geometric parameter
  • mesh the faces
  • save the project under another name
3 Close the command file

Stage 2: final result

The command file ModifParam.py containing the saved sequence is presented as follows:

Stage 3

To modify the previous command file using the PyFlux syntax:

Step Action
1 Write a function in the PyFlux language, which enables the automatic creation of a Flux project (corresponding to a set of parameters) starting from a base project BASE.FLU.
2 Write the calls of the previous function to create the 3 desired cases
3 Save the command file

Stage 3: file explanation

The command file ModifyParam.py containing the modify() function and the calls of this function is presented as follows:

Element Function
#! Preflu2D 9.33
indication on the executable program
def modify(VX1,VY1,VX2,VY2,VX3,VY3,case)

definition of the modify() function having as input 7 parameters

(6 numerical values to define the geometric parameters X1, Y1, X2, Y2, X3, Y3 and 1 string to define the name of the project)

deletion of the mesh
ParameterGeom['X1'].expression= str(VX1)

modification of geometric parameter

(X1 takes the value VX1 , converted into string by the method s tr() ,


meshing faces
saving the project under the name defined by the input parameter case

call of the function to build the first case,

Stage 4

Run the command file.

Stage 4: final result

After running the command file, the user has in his/her working directory 4 Flux projects, whose characteristics are given in the table below.

P1: ( 0, 0) P1: ( 0, 0) P1: ( 0, 0) P1: ( 0, 0)
P2: (20, 0) P2: (10, 0) P2: (10, 0) P2: (10, 0)
P3: ( 0, 10) P3: ( 0, 10) P3: (10, 10) P3: ( 0, 10)
P4: (20, 10) P4: (20, 10) P4: (20, 10) P4: (15, 5)