Post-processing helps you inspect the solution and communicate its physical meaning.
A useful figure identifies the field being shown, its units, its location, and any reference-frame choices needed to interpret it.
Learning objective
Create clear pressure and velocity visualizations and explain what they show.
Key idea
Every CFD figure should answer a defined question and provide enough information for another person to interpret it correctly.
Understand the idea
Open the case using the method documented in the starter and select the intended saved solution.
Use a Slice to inspect a plane through the flow. Use Glyphs to display velocity direction and magnitude at selected locations. Use Stream Tracer to explore the direction of a selected velocity field.
A streamline is tangent to the velocity field at the selected solution state. In unsteady flow, it is not generally the same as a particle trajectory.
Check which velocity is displayed: absolute and relative velocities have different meanings.
Also verify the pressure field’s dimensions. Some incompressible solvers use pressure divided by density. Do not label that field in pascals without applying the appropriate interpretation or conversion
Engineering example
Create a slice passing through the rotor axis and colour it by velocity magnitude.
Use it to identify acceleration, low-speed regions, and possible recirculation. Inspect vectors or streamlines before drawing conclusions about flow direction.
For comparisons, keep the viewing plane, camera position, field definition, and colour scale consistent.
Practical task
Export three figures:
- A velocity-magnitude slice.
- A pressure view with correctly identified units.
- A streamline view with its velocity field and seed location documented.
Add a caption explaining the engineering observation in each figure.
Checkpoint
Why can two automatically scaled colour plots be misleading when compared?
Their colours may represent different numerical values. Using a common scale helps distinguish real differences from differences caused by the display settings.