Pre-processing

The definition of the geometry is the first step to solve any problem. To create the box that encapsulates the flow, we only have to create the respective points, lines and surfaces using the Pre-processor tools. In the following paragraph we will show the necessary steps to create the geometry.

The definition of the geometry is the first step to solve any problem. To create the box that encapsulates the flow, we only have to create the respective points, lines and surfaces using the Pre-processor tools. From the surfaces we will define the so-called control volume, to which the boundary conditions will have to be assigned. In the following paragraph we will show the necessary steps to create the control volume.

First the points with the co-ordinates listed below have to be entered using one of the many methods provided by the Pre-processor:

               

Nº:

Coordinates:

 

 

1

0.000000

0.000000

0.000000

2

0.000000

0.000000

1.000000

3

0.000000

1.000000

0.000000

4

0.000000

1.000000

1.000000

5

1.000000

0.000000

0.000000

6

1.000000

0.000000

1.000000

7

1.000000

1.000000

0.000000

8

1.000000

1.000000

1.000000

Then the lines have to be created from the corresponding points, using the Create Line (use “Join” or Ctrl+A) option.

Once all the lines are defined, the surfaces have to be created using the tool Geometry > Create > NURBS surface > By contour and selecting the contour lines of the corresponding surface.

The previously created surfaces will define a single volume, which is the control volume. To create the volume the Create Volume option has to be used. If the volume cannot be created for whatever reasons, check that all the surfaces were properly created, that there were no duplicated lines and that all the surfaces belong to a single and eventually closed volume.

Thus we finally obtain the geometry shown in Figure 1:

Figure 1Final geometry for the analysis