CFD provides a wealth of data for evaluating external flow features and performance, these include: Velocity and pressure field distributions, for instance to predict and control drag and lift. Visualisation of fluid flow over surfaces.

The jet plane considered here, has a zero incidence with the air flow.
The picture is an example of the pressure distribution on the jet plane. The red color is used to highlight high pressure region. Here the larger red region is actually the engine intake region.
In addition to the pressure field, pathlines are used to highlight the flow field surrounding the jet.

CFD can be use to predict high speed compressible flows such as a engine exhaust. Here, flow velocity can reach very high values (1000 m/s) with very high temperatures (1500 K).
The picture highlights an exhaust expansion in the free atmosphere. The pattern of evenly spaced rings sometimes visible in the exhaust of an engine is typically referred to as shock diamonds or Mach disks. The phenomenon occurs anytime a flow exits a nozzle at supersonic speeds and at a pressure that is different than that of the external atmosphere.