Step 9: Show Flow Distribution in the Elbow

Create a vector plot to show the flow distribution in the elbow:

1.   From the menu bar, select Insert/Vector.

2.   Click OK to accept the default name. The Details view for the vector appears.

3.   On the Geometry tab, set Domains to fluid and Locations to symmetry.

4.   Click Apply.

5.   On the Symbol tab, set Symbol Size to 4.

6.   Click Apply and notice the changes to the vector plot.

Figure 1.7: Vector Plot of Velocity

7.   Change the vector plot so that the vectors are colored by temperature:

(a)   In the Details view for Vector 1, click on the Color tab.

(b)   Set the Mode to Variable. The Variable field becomes enabled.

(c)   Click on the down arrow beside the Variable field to set it to Temperature.

(d)   Click Apply and notice the changes to the vector plot.

8.   Optionally, change the vector symbol. In the Details view for the vector, go to the Symbol tab and set Symbol to Arrow3D. Click Apply.

9.   Hide the vector plot by right-clicking on a vector symbol in the plot and selecting Hide.

CFD-Post uses the Variable setting on the Geometry tab to determine where to place objects to best illustrate changes in that variable. Once the object has been put in place, you can have CFD-Post measure other variables along those streamlines by using the Variable setting on the Color tab. In this example you will create streamlines to show the flow distribution by velocity, then recolor those streamlines to show turbulent kinetic energy:

1.   From the menu bar select Insert/Streamline. Accept the default name and click OK.

2.   In the Details view for Streamline 1, choose the points from which to start the streamlines. Click on the down arrow beside the Start From drop-down widget to see the potential starting points. Hover over each point and notice that the area is highlighted in the 3D Viewer. It would be best to show how streamlines from both inlets interact, so, to make a multi-selection, click the Location editor icon . The Location Selector dialog box appears.

3.   In the Location Selector dialog box, hold down the Ctrl key and click velocity inlet 5 and velocity inlet 6 to highlight both locations, then click OK.

4.   Click Preview Seed Points to see the starting points for the streamlines.

5.   On the Geometry tab, ensure that Variable is set to Velocity.

6.   Click on the Color tab and make the following changes:

(a)   Set the Mode to Variable. The Variable field becomes enabled.

(b)   Set the Variable to Turbulence Kinetic Energy.

(c)   Set Range to Local.

7.   Click Apply. The streamlines show the flow of massless particles through the entire domain.

Figure 1.8: Streamlines of Turbulence Kinetic Energy

8.   Select the check box beside Vector 1. The vectors appear, but are largely hidden by the streamlines. To correct this, highlight Streamline 1 in the Outline tree view and press Delete. The vectors are now clearly visible, but the work you did to create the streamlines is gone. Click the Undo icon to restore Streamline 1.

9.   Hide the vector plot and the streamlines by clearing the check boxes beside Vector 1 and Streamline 1 in the Outline tree view.