Analyzing the Results

After the simulation has finished running, you examine Vector Scene 1, and the Wall Shear Stress (x) and Nusselt Number plots.

To analyze the results:
  1. Open Scenes > Vector Scene 1.


    At the inlet of the backwards facing step, there is a clear parabolic velocity profile visible, with the velocity reaching a maximum value of 0.997 m/s at the centerline of the channel, and a much lower velocity magnitude is at the channel walls. Once the flow reaches the step and the flow expands and separates, the velocity magnitude decreases. Behind the step, the recirculation zone forms and the velocity magnitude in this region is significantly lower compared to the approaching flow.

  2. Open Plots > Wall Shear Stress (x).


    The wall shear stress in the x direction steadily decreases from 0.0 Pa to a lowest value of approximately -0.00025 Pa at 3.0 m across the bottom step boundary. This is likely a result of the recirculation zone after the airflow has passed the step. From 3.0 m onwards, the wall shear stress in the x direction steadily increases, reaching a peak value of 0.00125 Pa at the outlet.

  3. Open Plots > Nusselt Number.


    As the bottom of the step is heated, the Nusselt number rapidly increases across this surface (up to 3.8 m). This is the recirculation zone. As the flow continues past this point, the Nusselt number continues to increase but at a much slower rate, reaching a maximum value of approximately 44 at the outlet.