A streamline is the path that a particle of zero mass would take through the fluid domain. The path is calculated using a Runge-Kutta method of vector variable integration with variable timestep control. Streamlines start at each node on a given locator.
The assumption of steady-state flow is assumed when a streamline is created, even with a transient simulation. Although the CFD-Post streamline algorithm is efficient, the calculation of large numbers of streamlines in a large domain can still take a long period of time. Therefore, when calculating streamlines for a solution for the first time, start by plotting a small number of streamlines and then increase the number of streamlines until the best generation time vs. detail ratio is found.
Note: In multi-domain turbo cases, streamlines may not always cross from one domain to next. This can happen when there is no overlap between the two domains, or when the domain interface is not modeled as an interface, but rather as outlet/inlet pair (for example, in Fluent). If you want to view streamlines in both domains in such cases, you can start the streamlines from both "inlets", or from the inlet and the outlet, setting the Direction to be Forward and Backward.
The following characteristics of streamlines will be discussed:
Note: There are several ways to insert a streamline:
From the menu bar, select Insert > Streamline.
From the toolbar, click the Streamline
icon.Depending on the context, you may be able to perform an insert from the shortcut menu in the tree view or in the 3D Viewer.