Stream lines

Menu: View results->Stream lines

With this option you can display a stream line, or in fluid dynamics, a particle tracing, in a vector field.

Note: stream lines are confined in a single volume mesh, i.e. they do not jump from one volume mesh to the next volume mesh, even if they are close neighbors. In the provided example there are three volume meshes and stream lines will not cross the volume boundaries. You can join the volume meshes into a new single volume mesh using Geometry->Join->Volume sets . Then you can delete the three separate volumes and switch the single joined volume mesh on.

The above image results from doing this tutorial with the three separated volumes. The image at the end of this stream lines tutorial is achieved if following step is done before the enumerated stream lines tutorial steps.

Select Geometry->Join->Volume sets to create a single volume mesh, and delete the three other volume meshes: V volumes, V cil and V wake.

• Select View results->Default analysis/step->RANSOL->103.0 through the menu bar or clicking on 
• Select View results->Stream lines->Along line->Velocity through the menu bar

With this option you can define a segment along which several start points will be chosen. The number of points will also be asked for, including the ends of the segment. In the case of just one start point, this will be the center of the segment.

 NOTE: This action could also be done clicking on in the icon bar. In this case we have to select the way to define the start point through the mouse menu. In this case select Contextual->Along line.
We want to create several stream lines along the model doing 2 lines.

• Write the initial point in the command line 10,15,3
• Write the final point in the command line 10,-15,3
• You are asked for the number of points along the line. Enter 5 and click Ok.

The first line with 5 stream lines is created, repeat it to sample other line:

• Write the initial point in the command line 10,15,7
• Write the final point in the command line 10,-15,7
• You are asked for the number of points along the line. Choose 3.

The second series of 3 stream lines is created.

• Click the middle mouse button or press the <Esc> key in order to finish the operation.

Several configuration options can be set via the Preferences window  : Postprocess->Stream lines

• Play with some of the Stream lines options, like:
• Color mode: Stream contour filled (remember to set the contour fill color map mode to rainbow).

The stream lines will be drawn with the colors used in the velocity contour fill.

• Set Show arrows , with Size: 30 and Spacing: 10
• You may play with the different stream line Detail level: Points, Ribbons or 4 sided prisms. If the ribbons type is selected you may adjust the initial swirl angle to rotate the ribbon.
• Close the window
• Select View results->Delete->Stream lines->All

 NOTE: A way to achieve the best results is to first create a cut of the volume mesh through the region of interest and then use these nodal information as support to create stream lines and its options: along line, in a quad, etc.