Plus 2.X:3D-Objects

General Information

Figure 1: The 3D-Object

WUFI plus offers the possibility to model 3D thermal bridges. In this chapter the procedure is explained using the easy example of a thermal bridge you can see in the picture on the left. There is a movie to be found at the end of this chapter to help you understand how to create a 3D-Object.

Figure 2: The Input Mask

To model a thermal bridge a new 3D-Object must be created. This can be done by clicking on the "New" button in the 3D-Objects section in the Navigation Tree. The newly created object appears in the Navigation Tree and can then be edited.
The whole input mask for the 3D Objects looks like shown in Figure 2.

Measures

The first step is inputting the right measures along x, y, and z axis, this is done in the part of the input mask that is shown in Figure 3.

Figure 3: Measure-Input

For each change of material, a new division must be created and dimensioned. This can be done by using the "New", "Delete", "Copy" and "Insert" button. According to Figure 1, input should look like this:

Figure 4: Finished Measure-Input

There is a movie at the end of this page for better understanding.

Figure 5:Materials

Materials and Boundary Conditions

The second step is to assign the right materials and boundary conditions. First, requested materials need to be selected from the database using the "Add" button. In this case brick and concrete are chosen (see Figure 1).

Figure 6:Materials and boundary conditions along the x-axis

In principle to assign a material or boundary condition to the right element, choose the division, select the material or boundary condition and click on the element.

X-Axis

If this is done in the x-axis tab, the procedure is the following:

• Imagine you look at the 3D-Element in direction of the green arrow (=in viewing direction of the x-axis) in Figure 6.
• Imagine you "cut the element into slices" along the measurement units (=each time there is a change of material). As you can see in Figure 6 you get five "slices" (or divisions): Boundary Condition on the outside, 1,2,3 and Boundary Condition on the inside.

Figure 7: First Division-B.Cond.

• It is started with the uppermost division, the (outside) Boundary Condition (B. Cond.)[1]. After clicking onto it, this "slice" is displayed in the picture below (in view direction of the x-axis). The first division is the Boundary Condition i.e. the outer air so "climate" [2] is selected and then the elements below are clicked on[3]. Now "climate" is assigned to them and they turn blue.

• 

  Figure 8: Second Division
  Next the second division is selected, this is section 1 in Figure 6 above. Obviously the whole area is brick, so brick is selected and then assigned to the three elements by clicking onto them. The small outer elements remain untouched, they are adiabat, there is no heat exchange happening through them as they are only the continuance of the walls.
  
• 

  Figure 9:Third Division
  After that, the third division is chosen, this is area 2 in Figure 6. This "slice" of the wall has both a brick and a concrete part. The outer parts are brick, the inner one is concrete.
  
• 

  Figure 10: Fourth Division
  The fourth division (area 3 in Figure 6) gets concrete assigned to its middle part and as the two outer areas are inner air, they belong to "Zone 1:Heated Zone".
  
• Last the fifth division remains untouched, it's adiabat.

Figure 11:Input Y-Axis

Figure 12:Input Z-Axis

Y-Axis and Z-Axis

If input made for the x-axis was correct and complete, input for y- and z-axis is correct too automatically. However check it, to make sure everything is correct. If everything was done the right way input should look like Figure 11 and 12.
For better understanding of these steps watch the movie at the end of this page. <nr>

Graphic Window and Monitor Positions

Figure 13: Graphic Window

After finishing all tasks above the display of the 3D-Element should look like Figure 13.
There are a couple of possible operations in the graphic window:

• Number 1
  • Rotating around X, Y and Z Axis (use left and right mouse for different directions); Rotating can also be done by clicking onto the requested axis and using the scroll wheel to rotate.
  • Centering the display
  • Zooming in (left mouse) and out (right mouse) of the display; Zooming is also possible using the scroll wheel of the mouse (only if no axis is selected i.e. red)
• Number 2: The elements to be shown can be selected user defined.
  • It is possible to display all elements
  • Also only selected materials (i.e. ONLY concrete or ONLY masonry)can be displayed
  • It can be decided whether only one layer should be displayed; Select this layer on the left side in one of the tabs (X,Y,Z) and choose the desired division.
• Number 3: Display of boundary conditions can be switched off, if you do so, only the "solid" materials are displayed.

Figure 14: Monitor Position 1

Figure 15: Monitor Position 2

• Number 4: You can set monitor positions. Click the button and another window opens up where you can enter coordinates. Note, that these coordinates belong to the coordinate system that was used to input the 3D-Object, that is the one shown in Figure 1.

For example one monitor position could be set into the upper edge between brick and concrete (See Figure 14). Its coordinates are:
X=0.3
Y=1.2
Z=0,5
If monitor positions were defined, they are displayed as dots in the picture on the down left side of the input window (see Figure 15).
For these monitor positions temperature is calculated during a calculation and values can be found in the export-section after a calculation.

"Initial temperature" and "Show fine division"

Figure 16: "Initial temperature" and "Show fine division"

• Before a calculation the initial temperature of the elements can be set as requested.
• Show fine division: If fine division is checked, the grid (the way 3D Object is discretised) is displayed. The grid can be altered as desired in the grid section.

There is a movie at the end of this page. Watch it to see how monitor positions are set.

Calculation

During a calculation temperature distribution inside an object can be observed by the user in viewing direction of all axes and for all divisions. If smooth is checked, the display of the distributions is smoothed during the calculation, however this has no effect on the results.

Figure 17: Display during the calculation

Results for monitor positions can be found in the export-section after the calculation.

Movie

All that is described above is shown in this movie.