Plotting Streamlines

An effective way of visualizing a flow pattern is to draw streamlines, i.e. tracks of imaginary massless particles introduced into the flow at specified points. Here we will draw streamlines originating at the smaller inlet.

Double-click the Geometry Scene 1 node to display the problem geometry

Select the Geometry Scene 1 > Displayers > Geometry 1 node

In the Properties window, clear the Mesh checkbox

Select the Geometry 1 > Parts node and make sure that the only Parts selected for display are Fluid: inlet, Fluid: inlet2, Fluid: outlet and Fluid: wall.

Right-click on the Derived Parts node and select option New Part > Streamline

A new interactive in-place dialog appears on the left of the Graphics window enabling you to define the desired streamlines.

Accept the default settings for Input Parts (Fluid), Vector (Velocity) and Seed Mode (Part Seed)

Select Fluid: inlet 2 from the Seed Part list, as shown below.

Click Create, which will immediately display the desired streamlines, and then Close.

A new node called streamline will also appear in the simulation tree. To enhance the clarity of the display:

Open the streamline node and then select node Source Seed

In the Properties window, change both the U Points and V Points properties to 2

Select the Geometry 1 displayer node within the Geometry Scene 1 node and then change the Opacity property to 0.3. This will display the streamline tracks more clearly, as shown below.

The above plot illustrates very clearly the swirling nature of the flow. Streamlines can also be plotted together with vectors or contours, as in the following example.

Open the Scenes node and then double-click the Scalar Scene 2 node to display the previously produced cross-sectional plot

Select the Scalar Scene 2 > Displayers > Scalar 1 > Scalar Field node

In the Properties window, select Temperature from the Function pop-up menu to produce a temperature plot on the pre-selected cross section.

Select the Parts node and add the streamline part to the scene. The streamlines will be displayed in the Graphics window

Select the Scalar Scene 2 > Displayers > Scalar 1 node and, in the Properties window, change the Line Width value to 2 to see the streamlines more clearly.

Note that the streamlines are colored according to the local temperature along their path.

This completes the post-processing part of the tutorial. Descriptions of more complex post-processing operations may be found in some of the other tutorials in the STAR-CCM+ Training Guide.